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    <title>DEV Community: Diego Fernando Castillo Mamani</title>
    <description>The latest articles on DEV Community by Diego Fernando Castillo Mamani (@diegocastillo12).</description>
    <link>https://dev.to/diegocastillo12</link>
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      <title>DEV Community: Diego Fernando Castillo Mamani</title>
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    <item>
      <title>Securing Infrastructure as Code with Checkov: A Practical SAST Approach</title>
      <dc:creator>Diego Fernando Castillo Mamani</dc:creator>
      <pubDate>Fri, 05 Dec 2025 20:31:57 +0000</pubDate>
      <link>https://dev.to/diegocastillo12/securing-infrastructure-as-code-with-checkov-a-practical-sast-approach-2l56</link>
      <guid>https://dev.to/diegocastillo12/securing-infrastructure-as-code-with-checkov-a-practical-sast-approach-2l56</guid>
      <description>&lt;h2&gt;
  
  
  Introduction
&lt;/h2&gt;

&lt;p&gt;Infrastructure as Code (IaC) has revolutionized how we manage and deploy cloud resources. However, with great power comes great responsibility. Security misconfigurations in IaC templates can lead to serious vulnerabilities in production environments. This is where Static Application Security Testing (SAST) tools like Checkov come into play.&lt;/p&gt;

&lt;p&gt;In this article, we'll explore how to implement Checkov, a powerful open-source SAST tool, to scan and secure your Infrastructure as Code across multiple platforms including Terraform, CloudFormation, Kubernetes, and more.&lt;/p&gt;

&lt;h2&gt;
  
  
  What is Checkov?
&lt;/h2&gt;

&lt;p&gt;Checkov is a static code analysis tool developed by Bridgecrew (now part of Palo Alto Networks) that scans infrastructure code for security and compliance misconfigurations. It supports:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Terraform&lt;/li&gt;
&lt;li&gt;CloudFormation&lt;/li&gt;
&lt;li&gt;Kubernetes&lt;/li&gt;
&lt;li&gt;Helm&lt;/li&gt;
&lt;li&gt;ARM Templates&lt;/li&gt;
&lt;li&gt;Serverless Framework&lt;/li&gt;
&lt;li&gt;Docker&lt;/li&gt;
&lt;li&gt;And many more...&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  Why Use SAST for Infrastructure as Code?
&lt;/h2&gt;

&lt;p&gt;&lt;strong&gt;Early Detection&lt;/strong&gt;: Identify security issues before they reach production&lt;br&gt;
&lt;strong&gt;Compliance&lt;/strong&gt;: Ensure adherence to industry standards (CIS, PCI-DSS, HIPAA)&lt;br&gt;
&lt;strong&gt;Cost Reduction&lt;/strong&gt;: Fix issues early in the development cycle&lt;br&gt;
&lt;strong&gt;Automation&lt;/strong&gt;: Integrate seamlessly into CI/CD pipelines&lt;br&gt;
&lt;strong&gt;Policy as Code&lt;/strong&gt;: Define and enforce organizational security policies&lt;/p&gt;
&lt;h2&gt;
  
  
  Getting Started with Checkov
&lt;/h2&gt;
&lt;h3&gt;
  
  
  Installation
&lt;/h3&gt;

&lt;p&gt;Checkov can be installed using pip:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;pip &lt;span class="nb"&gt;install &lt;/span&gt;checkov
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Or using Docker:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;docker pull bridgecrew/checkov
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Basic Usage
&lt;/h3&gt;

&lt;p&gt;Scan a Terraform directory:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;checkov &lt;span class="nt"&gt;-d&lt;/span&gt; /path/to/terraform
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Scan a specific file:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;checkov &lt;span class="nt"&gt;-f&lt;/span&gt; main.tf
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Practical Example: Securing Terraform Code
&lt;/h2&gt;

&lt;p&gt;Let's examine a vulnerable Terraform configuration and how Checkov identifies the issues.&lt;/p&gt;

&lt;h3&gt;
  
  
  Vulnerable Configuration
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight hcl"&gt;&lt;code&gt;&lt;span class="c1"&gt;# main.tf - INSECURE EXAMPLE&lt;/span&gt;
&lt;span class="nx"&gt;resource&lt;/span&gt; &lt;span class="s2"&gt;"aws_s3_bucket"&lt;/span&gt; &lt;span class="s2"&gt;"data_bucket"&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;bucket&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"my-data-bucket"&lt;/span&gt;

  &lt;span class="c1"&gt;# Missing encryption&lt;/span&gt;
  &lt;span class="c1"&gt;# Missing versioning&lt;/span&gt;
  &lt;span class="c1"&gt;# Missing logging&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="nx"&gt;resource&lt;/span&gt; &lt;span class="s2"&gt;"aws_security_group"&lt;/span&gt; &lt;span class="s2"&gt;"web_sg"&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;name&lt;/span&gt;        &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"web-security-group"&lt;/span&gt;
  &lt;span class="nx"&gt;description&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"Security group for web servers"&lt;/span&gt;

  &lt;span class="nx"&gt;ingress&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nx"&gt;from_port&lt;/span&gt;   &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;
    &lt;span class="nx"&gt;to_port&lt;/span&gt;     &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;
    &lt;span class="nx"&gt;protocol&lt;/span&gt;    &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"-1"&lt;/span&gt;
    &lt;span class="nx"&gt;cidr_blocks&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"0.0.0.0/0"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;  &lt;span class="c1"&gt;# Too permissive!&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="nx"&gt;resource&lt;/span&gt; &lt;span class="s2"&gt;"aws_db_instance"&lt;/span&gt; &lt;span class="s2"&gt;"database"&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;allocated_storage&lt;/span&gt;    &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;20&lt;/span&gt;
  &lt;span class="nx"&gt;engine&lt;/span&gt;              &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"mysql"&lt;/span&gt;
  &lt;span class="nx"&gt;instance_class&lt;/span&gt;      &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"db.t3.micro"&lt;/span&gt;
  &lt;span class="nx"&gt;username&lt;/span&gt;            &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"admin"&lt;/span&gt;
  &lt;span class="nx"&gt;password&lt;/span&gt;            &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"hardcodedpassword123"&lt;/span&gt;  &lt;span class="c1"&gt;# Hardcoded password!&lt;/span&gt;
  &lt;span class="nx"&gt;skip_final_snapshot&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

  &lt;span class="c1"&gt;# Missing encryption&lt;/span&gt;
  &lt;span class="c1"&gt;# Publicly accessible by default&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Running Checkov
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;checkov &lt;span class="nt"&gt;-f&lt;/span&gt; main.tf &lt;span class="nt"&gt;--output&lt;/span&gt; json &lt;span class="nt"&gt;--output-file&lt;/span&gt; results.json
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Checkov Output
&lt;/h3&gt;

&lt;p&gt;Checkov will identify multiple security issues:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;Check: CKV_AWS_18: "Ensure the S3 bucket has access logging enabled"
Check: CKV_AWS_19: "Ensure the S3 bucket has server-side encryption enabled"
Check: CKV_AWS_21: "Ensure the S3 bucket has versioning enabled"
Check: CKV_AWS_23: "Ensure Security Group does not allow ingress from 0.0.0.0/0 to port 22"
Check: CKV_AWS_16: "Ensure RDS database is encrypted at rest"
Check: CKV_AWS_41: "Ensure RDS instance has IAM authentication enabled"
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Secure Configuration
&lt;/h3&gt;

&lt;p&gt;Now let's fix these issues:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight hcl"&gt;&lt;code&gt;&lt;span class="c1"&gt;# main.tf - SECURE VERSION&lt;/span&gt;
&lt;span class="nx"&gt;resource&lt;/span&gt; &lt;span class="s2"&gt;"aws_s3_bucket"&lt;/span&gt; &lt;span class="s2"&gt;"data_bucket"&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;bucket&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"my-data-bucket"&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="nx"&gt;resource&lt;/span&gt; &lt;span class="s2"&gt;"aws_s3_bucket_versioning"&lt;/span&gt; &lt;span class="s2"&gt;"data_bucket_versioning"&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;bucket&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;aws_s3_bucket&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;data_bucket&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;id&lt;/span&gt;
  &lt;span class="nx"&gt;versioning_configuration&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nx"&gt;status&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"Enabled"&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="nx"&gt;resource&lt;/span&gt; &lt;span class="s2"&gt;"aws_s3_bucket_server_side_encryption_configuration"&lt;/span&gt; &lt;span class="s2"&gt;"data_bucket_encryption"&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;bucket&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;aws_s3_bucket&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;data_bucket&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;id&lt;/span&gt;

  &lt;span class="nx"&gt;rule&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nx"&gt;apply_server_side_encryption_by_default&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="nx"&gt;sse_algorithm&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"AES256"&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="nx"&gt;resource&lt;/span&gt; &lt;span class="s2"&gt;"aws_s3_bucket_logging"&lt;/span&gt; &lt;span class="s2"&gt;"data_bucket_logging"&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;bucket&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;aws_s3_bucket&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;data_bucket&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;id&lt;/span&gt;

  &lt;span class="nx"&gt;target_bucket&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;aws_s3_bucket&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;log_bucket&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;id&lt;/span&gt;
  &lt;span class="nx"&gt;target_prefix&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"log/"&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="nx"&gt;resource&lt;/span&gt; &lt;span class="s2"&gt;"aws_security_group"&lt;/span&gt; &lt;span class="s2"&gt;"web_sg"&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;name&lt;/span&gt;        &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"web-security-group"&lt;/span&gt;
  &lt;span class="nx"&gt;description&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"Security group for web servers"&lt;/span&gt;

  &lt;span class="nx"&gt;ingress&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nx"&gt;from_port&lt;/span&gt;   &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;443&lt;/span&gt;
    &lt;span class="nx"&gt;to_port&lt;/span&gt;     &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;443&lt;/span&gt;
    &lt;span class="nx"&gt;protocol&lt;/span&gt;    &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"tcp"&lt;/span&gt;
    &lt;span class="nx"&gt;cidr_blocks&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"10.0.0.0/8"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;  &lt;span class="c1"&gt;# Restricted to internal network&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;

  &lt;span class="nx"&gt;egress&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nx"&gt;from_port&lt;/span&gt;   &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;
    &lt;span class="nx"&gt;to_port&lt;/span&gt;     &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;
    &lt;span class="nx"&gt;protocol&lt;/span&gt;    &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"-1"&lt;/span&gt;
    &lt;span class="nx"&gt;cidr_blocks&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"0.0.0.0/0"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="nx"&gt;resource&lt;/span&gt; &lt;span class="s2"&gt;"aws_db_instance"&lt;/span&gt; &lt;span class="s2"&gt;"database"&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;allocated_storage&lt;/span&gt;    &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;20&lt;/span&gt;
  &lt;span class="nx"&gt;engine&lt;/span&gt;              &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"mysql"&lt;/span&gt;
  &lt;span class="nx"&gt;instance_class&lt;/span&gt;      &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"db.t3.micro"&lt;/span&gt;
  &lt;span class="nx"&gt;username&lt;/span&gt;            &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"admin"&lt;/span&gt;
  &lt;span class="nx"&gt;password&lt;/span&gt;            &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;var&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;db_password&lt;/span&gt;  &lt;span class="c1"&gt;# Using variable instead&lt;/span&gt;
  &lt;span class="nx"&gt;skip_final_snapshot&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;

  &lt;span class="nx"&gt;storage_encrypted&lt;/span&gt;          &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
  &lt;span class="nx"&gt;iam_database_authentication_enabled&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
  &lt;span class="nx"&gt;publicly_accessible&lt;/span&gt;        &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="kc"&gt;false&lt;/span&gt;

  &lt;span class="nx"&gt;backup_retention_period&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;7&lt;/span&gt;
  &lt;span class="nx"&gt;enabled_cloudwatch_logs_exports&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"error"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"general"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="s2"&gt;"slowquery"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Integrating Checkov into CI/CD
&lt;/h2&gt;

&lt;h3&gt;
  
  
  GitHub Actions Example
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;IaC Security Scan&lt;/span&gt;

&lt;span class="na"&gt;on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="nv"&gt;push&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;pull_request&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;

&lt;span class="na"&gt;jobs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;checkov&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;runs-on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ubuntu-latest&lt;/span&gt;
    &lt;span class="na"&gt;steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Checkout code&lt;/span&gt;
        &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/checkout@v3&lt;/span&gt;

      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Set up Python&lt;/span&gt;
        &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/setup-python@v4&lt;/span&gt;
        &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;python-version&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;3.9'&lt;/span&gt;

      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Install Checkov&lt;/span&gt;
        &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;pip install checkov&lt;/span&gt;

      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Run Checkov&lt;/span&gt;
        &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
          &lt;span class="s"&gt;checkov -d . --output cli --output json --output-file checkov-report.json&lt;/span&gt;

      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Upload results&lt;/span&gt;
        &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/upload-artifact@v3&lt;/span&gt;
        &lt;span class="na"&gt;if&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;always()&lt;/span&gt;
        &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;checkov-report&lt;/span&gt;
          &lt;span class="na"&gt;path&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;checkov-report.json&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  GitLab CI Example
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="na"&gt;checkov&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;stage&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;test&lt;/span&gt;
  &lt;span class="na"&gt;image&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;bridgecrew/checkov:latest&lt;/span&gt;
  &lt;span class="na"&gt;script&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;checkov -d . --output cli --output junitxml --output-file checkov-report.xml&lt;/span&gt;
  &lt;span class="na"&gt;artifacts&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;reports&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;junit&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;checkov-report.xml&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Custom Policies
&lt;/h2&gt;

&lt;p&gt;Checkov allows you to create custom policies using Python:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;from&lt;/span&gt; &lt;span class="n"&gt;checkov.common.models.enums&lt;/span&gt; &lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;CheckResult&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;CheckCategories&lt;/span&gt;
&lt;span class="kn"&gt;from&lt;/span&gt; &lt;span class="n"&gt;checkov.terraform.checks.resource.base_resource_check&lt;/span&gt; &lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;BaseResourceCheck&lt;/span&gt;

&lt;span class="k"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;S3BucketEncryption&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;BaseResourceCheck&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
    &lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;__init__&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;self&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
        &lt;span class="n"&gt;name&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;Ensure S3 bucket is encrypted with KMS&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
        &lt;span class="nb"&gt;id&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;CKV_AWS_CUSTOM_1&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
        &lt;span class="n"&gt;supported_resources&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;aws_s3_bucket&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
        &lt;span class="n"&gt;categories&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="n"&gt;CheckCategories&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;ENCRYPTION&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
        &lt;span class="nf"&gt;super&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="nf"&gt;__init__&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;name&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;name&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nb"&gt;id&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="nb"&gt;id&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;categories&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;categories&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; 
                         &lt;span class="n"&gt;supported_resources&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;&lt;span class="n"&gt;supported_resources&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;

    &lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;scan_resource_conf&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;self&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;conf&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;server_side_encryption_configuration&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;conf&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
            &lt;span class="n"&gt;encryption_config&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;conf&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;server_side_encryption_configuration&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
            &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;rule&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;encryption_config&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                &lt;span class="n"&gt;rule&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;encryption_config&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;rule&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
                &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;apply_server_side_encryption_by_default&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;rule&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
                    &lt;span class="n"&gt;encryption&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;rule&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;apply_server_side_encryption_by_default&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="p"&gt;][&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
                    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;encryption&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;sse_algorithm&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;==&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="s"&gt;aws:kms&lt;/span&gt;&lt;span class="sh"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]:&lt;/span&gt;
                        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;CheckResult&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;PASSED&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="n"&gt;CheckResult&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;FAILED&lt;/span&gt;

&lt;span class="n"&gt;check&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nc"&gt;S3BucketEncryption&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Best Practices
&lt;/h2&gt;

&lt;ol&gt;
&lt;li&gt;
&lt;strong&gt;Run Checkov Early&lt;/strong&gt;: Integrate it into your development workflow&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Use Suppressions Wisely&lt;/strong&gt;: Document why certain checks are suppressed&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Keep Checkov Updated&lt;/strong&gt;: New checks are added regularly&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Set Baseline&lt;/strong&gt;: Use &lt;code&gt;--baseline&lt;/code&gt; to track improvements over time&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Combine with Other Tools&lt;/strong&gt;: Use alongside dynamic testing and manual reviews&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Educate Your Team&lt;/strong&gt;: Ensure developers understand the security implications&lt;/li&gt;
&lt;/ol&gt;

&lt;h2&gt;
  
  
  Suppressing False Positives
&lt;/h2&gt;

&lt;p&gt;Sometimes you need to suppress legitimate findings:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight hcl"&gt;&lt;code&gt;&lt;span class="nx"&gt;resource&lt;/span&gt; &lt;span class="s2"&gt;"aws_security_group"&lt;/span&gt; &lt;span class="s2"&gt;"special_case"&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;name&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"special-sg"&lt;/span&gt;

  &lt;span class="c1"&gt;#checkov:skip=CKV_AWS_23:This SG is for internal load balancer&lt;/span&gt;
  &lt;span class="nx"&gt;ingress&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="nx"&gt;from_port&lt;/span&gt;   &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;80&lt;/span&gt;
    &lt;span class="nx"&gt;to_port&lt;/span&gt;     &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;80&lt;/span&gt;
    &lt;span class="nx"&gt;protocol&lt;/span&gt;    &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;"tcp"&lt;/span&gt;
    &lt;span class="nx"&gt;cidr_blocks&lt;/span&gt; &lt;span class="p"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"0.0.0.0/0"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Measuring Success
&lt;/h2&gt;

&lt;p&gt;Track these metrics to measure the effectiveness of Checkov:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Vulnerability Detection Rate&lt;/strong&gt;: Number of issues found per scan&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Fix Time&lt;/strong&gt;: Time from detection to remediation&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;False Positive Rate&lt;/strong&gt;: Percentage of findings that are not actual issues&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Coverage&lt;/strong&gt;: Percentage of infrastructure code being scanned&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Compliance Score&lt;/strong&gt;: Pass rate against security benchmarks&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  Conclusion
&lt;/h2&gt;

&lt;p&gt;Implementing SAST tools like Checkov is essential for maintaining secure infrastructure as code. By catching security issues early in the development cycle, you can:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Reduce security risks in production&lt;/li&gt;
&lt;li&gt;Ensure compliance with industry standards&lt;/li&gt;
&lt;li&gt;Foster a security-first culture&lt;/li&gt;
&lt;li&gt;Save time and money on remediation&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;Start small by integrating Checkov into one project, measure the results, and gradually expand coverage across your organization. Security is a journey, not a destination, and tools like Checkov are invaluable companions along the way.&lt;/p&gt;

&lt;h2&gt;
  
  
  References
&lt;/h2&gt;

&lt;ul&gt;
&lt;li&gt;&lt;a href="https://www.checkov.io/" rel="noopener noreferrer"&gt;Checkov Official Documentation&lt;/a&gt;&lt;/li&gt;
&lt;li&gt;&lt;a href="https://owasp.org/www-community/Source_Code_Analysis_Tools" rel="noopener noreferrer"&gt;OWASP Source Code Analysis Tools&lt;/a&gt;&lt;/li&gt;
&lt;li&gt;&lt;a href="https://www.terraform.io/docs/cloud/guides/recommended-practices/index.html" rel="noopener noreferrer"&gt;Terraform Security Best Practices&lt;/a&gt;&lt;/li&gt;
&lt;li&gt;&lt;a href="https://www.cisecurity.org/cis-benchmarks/" rel="noopener noreferrer"&gt;CIS Benchmarks&lt;/a&gt;&lt;/li&gt;
&lt;/ul&gt;




</description>
    </item>
    <item>
      <title>🚀Building Your First MCP Server: A Complete Guide</title>
      <dc:creator>Diego Fernando Castillo Mamani</dc:creator>
      <pubDate>Tue, 02 Dec 2025 04:42:44 +0000</pubDate>
      <link>https://dev.to/diegocastillo12/building-your-first-mcp-server-a-complete-guide-4m7d</link>
      <guid>https://dev.to/diegocastillo12/building-your-first-mcp-server-a-complete-guide-4m7d</guid>
      <description>&lt;h2&gt;
  
  
  Introduction
&lt;/h2&gt;

&lt;p&gt;The Model Context Protocol (MCP) is revolutionizing how AI applications interact with external tools and data sources. Whether you're building Claude integrations, VSCode extensions, or custom AI workflows, understanding MCP servers is essential for modern AI development.&lt;/p&gt;

&lt;p&gt;In this comprehensive guide, we'll build a fully functional MCP server from scratch, deploy it to the cloud, and connect it to popular MCP clients. By the end, you'll have a working weather information server that any MCP client can use.&lt;/p&gt;

&lt;h2&gt;
  
  
  What is MCP?
&lt;/h2&gt;

&lt;p&gt;MCP (Model Context Protocol) is an open protocol that standardizes how AI applications connect to external data sources and tools. Think of it as a universal adapter that allows AI models like Claude to safely access your databases, APIs, file systems, and business tools.&lt;/p&gt;

&lt;h3&gt;
  
  
  Key Benefits
&lt;/h3&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;strong&gt;Standardized Integration&lt;/strong&gt;: One protocol works across all MCP-compatible clients&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Security First&lt;/strong&gt;: Built-in authentication and permission controls&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Flexible Architecture&lt;/strong&gt;: Support for local and remote servers&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Tool Discovery&lt;/strong&gt;: Clients automatically discover available capabilities&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  Architecture Overview
&lt;/h2&gt;

&lt;p&gt;An MCP server consists of three main components:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;
&lt;strong&gt;Resources&lt;/strong&gt;: Data sources the server can provide (files, database records, API data)&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Tools&lt;/strong&gt;: Actions the server can perform (create, update, delete operations)&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Prompts&lt;/strong&gt;: Pre-defined templates for common tasks
&lt;/li&gt;
&lt;/ol&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;┌─────────────┐         ┌─────────────┐         ┌─────────────┐
│             │         │             │         │             │
│ MCP Client  │◄───────►│ MCP Server  │◄───────►│  External   │
│  (Claude)   │   MCP   │   (Your     │         │   APIs      │
│             │ Protocol│    Code)    │         │             │
└─────────────┘         └─────────────┘         └─────────────┘
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Building Our Weather MCP Server
&lt;/h2&gt;

&lt;p&gt;Let's build a practical MCP server that provides weather information using a public API.&lt;/p&gt;

&lt;h3&gt;
  
  
  Project Setup
&lt;/h3&gt;

&lt;p&gt;First, create a new project and install dependencies:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;&lt;span class="nb"&gt;mkdir &lt;/span&gt;weather-mcp-server
&lt;span class="nb"&gt;cd &lt;/span&gt;weather-mcp-server
npm init &lt;span class="nt"&gt;-y&lt;/span&gt;
npm &lt;span class="nb"&gt;install&lt;/span&gt; @modelcontextprotocol/sdk axios dotenv
npm &lt;span class="nb"&gt;install&lt;/span&gt; &lt;span class="nt"&gt;-D&lt;/span&gt; @types/node typescript
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Project Structure
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;weather-mcp-server/
├── src/
│   ├── index.ts
│   ├── server.ts
│   └── weatherService.ts
├── package.json
├── tsconfig.json
└── .env
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Configuration Files
&lt;/h3&gt;

&lt;p&gt;&lt;strong&gt;tsconfig.json&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight json"&gt;&lt;code&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="nl"&gt;"compilerOptions"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"target"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"ES2022"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"module"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"Node16"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"moduleResolution"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"Node16"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"outDir"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"./dist"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"rootDir"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"./src"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"strict"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"esModuleInterop"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"skipLibCheck"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"forceConsistentCasingInFileNames"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="kc"&gt;true&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="nl"&gt;"include"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"src/**/*"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="nl"&gt;"exclude"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"node_modules"&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;package.json&lt;/strong&gt; (add scripts)&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight json"&gt;&lt;code&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="nl"&gt;"scripts"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"build"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"tsc"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"start"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"node dist/index.js"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"dev"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"tsc &amp;amp;&amp;amp; node dist/index.js"&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="p"&gt;},&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="nl"&gt;"type"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"module"&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Weather Service Implementation
&lt;/h3&gt;

&lt;p&gt;&lt;strong&gt;src/weatherService.ts&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="nx"&gt;axios&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;axios&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="kr"&gt;interface&lt;/span&gt; &lt;span class="nx"&gt;WeatherData&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nl"&gt;location&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="nl"&gt;temperature&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;number&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="nl"&gt;condition&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="nl"&gt;humidity&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;number&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="nl"&gt;windSpeed&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;number&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="nl"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;WeatherService&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="k"&gt;private&lt;/span&gt; &lt;span class="nx"&gt;apiKey&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="k"&gt;private&lt;/span&gt; &lt;span class="nx"&gt;baseUrl&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;https://api.openweathermap.org/data/2.5&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

  &lt;span class="nf"&gt;constructor&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;apiKey&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;apiKey&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;apiKey&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;

  &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="nf"&gt;getCurrentWeather&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;city&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt; &lt;span class="nb"&gt;Promise&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nx"&gt;WeatherData&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;try&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;response&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;axios&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;baseUrl&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;/weather`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="na"&gt;params&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
          &lt;span class="na"&gt;q&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;city&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="na"&gt;appid&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;apiKey&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="na"&gt;units&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;metric&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
        &lt;span class="p"&gt;}&lt;/span&gt;
      &lt;span class="p"&gt;});&lt;/span&gt;

      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;response&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

      &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="na"&gt;location&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;name&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;, &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;sys&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;country&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;temperature&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;Math&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;round&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;main&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;temp&lt;/span&gt;&lt;span class="p"&gt;),&lt;/span&gt;
        &lt;span class="na"&gt;condition&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;weather&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;].&lt;/span&gt;&lt;span class="nx"&gt;main&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;humidity&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;main&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;humidity&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;windSpeed&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;wind&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;speed&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;weather&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;].&lt;/span&gt;&lt;span class="nx"&gt;description&lt;/span&gt;
      &lt;span class="p"&gt;};&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;catch &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;throw&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`Failed to fetch weather data: &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;

  &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="nf"&gt;getForecast&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;city&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;days&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;number&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;5&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt; &lt;span class="nb"&gt;Promise&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="kr"&gt;any&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;try&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;response&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;axios&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;baseUrl&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;/forecast`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="na"&gt;params&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
          &lt;span class="na"&gt;q&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;city&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="na"&gt;appid&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;apiKey&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="na"&gt;units&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;metric&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="na"&gt;cnt&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;days&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="mi"&gt;8&lt;/span&gt; &lt;span class="c1"&gt;// API returns 3-hour intervals&lt;/span&gt;
        &lt;span class="p"&gt;}&lt;/span&gt;
      &lt;span class="p"&gt;});&lt;/span&gt;

      &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;response&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;data&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;catch &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="k"&gt;throw&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`Failed to fetch forecast data: &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  MCP Server Implementation
&lt;/h3&gt;

&lt;p&gt;&lt;strong&gt;src/server.ts&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;Server&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@modelcontextprotocol/sdk/server/index.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;StdioServerTransport&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@modelcontextprotocol/sdk/server/stdio.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;CallToolRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;ListToolsRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;ListResourcesRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;ReadResourceRequestSchema&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@modelcontextprotocol/sdk/types.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;WeatherService&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;./weatherService.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="kd"&gt;class&lt;/span&gt; &lt;span class="nc"&gt;WeatherMCPServer&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="k"&gt;private&lt;/span&gt; &lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;Server&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="k"&gt;private&lt;/span&gt; &lt;span class="nx"&gt;weatherService&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;WeatherService&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

  &lt;span class="nf"&gt;constructor&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;apiKey&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;weatherService&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;WeatherService&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;apiKey&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;server&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Server&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
      &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;weather-mcp-server&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;version&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;1.0.0&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="p"&gt;},&lt;/span&gt;
      &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="na"&gt;capabilities&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
          &lt;span class="na"&gt;tools&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{},&lt;/span&gt;
          &lt;span class="na"&gt;resources&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{}&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
      &lt;span class="p"&gt;}&lt;/span&gt;
    &lt;span class="p"&gt;);&lt;/span&gt;

    &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;setupHandlers&lt;/span&gt;&lt;span class="p"&gt;();&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;

  &lt;span class="k"&gt;private&lt;/span&gt; &lt;span class="nf"&gt;setupHandlers&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="c1"&gt;// List available tools&lt;/span&gt;
    &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;setRequestHandler&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;ListToolsRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;async &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;({&lt;/span&gt;
      &lt;span class="na"&gt;tools&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
        &lt;span class="p"&gt;{&lt;/span&gt;
          &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;get_current_weather&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Get current weather information for a city&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="na"&gt;inputSchema&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;object&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="na"&gt;properties&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
              &lt;span class="na"&gt;city&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;string&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;City name (e.g., "London", "New York")&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
              &lt;span class="p"&gt;}&lt;/span&gt;
            &lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="na"&gt;required&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;city&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
          &lt;span class="p"&gt;}&lt;/span&gt;
        &lt;span class="p"&gt;},&lt;/span&gt;
        &lt;span class="p"&gt;{&lt;/span&gt;
          &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;get_forecast&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Get weather forecast for upcoming days&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="na"&gt;inputSchema&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;object&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="na"&gt;properties&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
              &lt;span class="na"&gt;city&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;string&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;City name&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
              &lt;span class="p"&gt;},&lt;/span&gt;
              &lt;span class="na"&gt;days&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;number&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Number of days (1-5)&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="na"&gt;default&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;5&lt;/span&gt;
              &lt;span class="p"&gt;}&lt;/span&gt;
            &lt;span class="p"&gt;},&lt;/span&gt;
            &lt;span class="na"&gt;required&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;city&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
          &lt;span class="p"&gt;}&lt;/span&gt;
        &lt;span class="p"&gt;}&lt;/span&gt;
      &lt;span class="p"&gt;]&lt;/span&gt;
    &lt;span class="p"&gt;}));&lt;/span&gt;

    &lt;span class="c1"&gt;// Handle tool calls&lt;/span&gt;
    &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;setRequestHandler&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;CallToolRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;async &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;name&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;arguments&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;args&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;params&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

      &lt;span class="k"&gt;try&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;name&lt;/span&gt; &lt;span class="o"&gt;===&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;get_current_weather&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
          &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;weather&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;weatherService&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getCurrentWeather&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
            &lt;span class="nx"&gt;args&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;city&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;
          &lt;span class="p"&gt;);&lt;/span&gt;

          &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="na"&gt;content&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
              &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;text&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="na"&gt;text&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;JSON&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;stringify&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;weather&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="kc"&gt;null&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
              &lt;span class="p"&gt;}&lt;/span&gt;
            &lt;span class="p"&gt;]&lt;/span&gt;
          &lt;span class="p"&gt;};&lt;/span&gt;
        &lt;span class="p"&gt;}&lt;/span&gt;

        &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;name&lt;/span&gt; &lt;span class="o"&gt;===&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;get_forecast&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
          &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;forecast&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;weatherService&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getForecast&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
            &lt;span class="nx"&gt;args&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;city&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
            &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;args&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;days&lt;/span&gt; &lt;span class="k"&gt;as&lt;/span&gt; &lt;span class="kr"&gt;number&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;||&lt;/span&gt; &lt;span class="mi"&gt;5&lt;/span&gt;
          &lt;span class="p"&gt;);&lt;/span&gt;

          &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
            &lt;span class="na"&gt;content&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
              &lt;span class="p"&gt;{&lt;/span&gt;
                &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;text&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
                &lt;span class="na"&gt;text&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;JSON&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;stringify&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;forecast&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="kc"&gt;null&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
              &lt;span class="p"&gt;}&lt;/span&gt;
            &lt;span class="p"&gt;]&lt;/span&gt;
          &lt;span class="p"&gt;};&lt;/span&gt;
        &lt;span class="p"&gt;}&lt;/span&gt;

        &lt;span class="k"&gt;throw&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`Unknown tool: &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;name&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
      &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;catch &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
          &lt;span class="na"&gt;content&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
            &lt;span class="p"&gt;{&lt;/span&gt;
              &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;text&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
              &lt;span class="na"&gt;text&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`Error: &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;
            &lt;span class="p"&gt;}&lt;/span&gt;
          &lt;span class="p"&gt;],&lt;/span&gt;
          &lt;span class="na"&gt;isError&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
        &lt;span class="p"&gt;};&lt;/span&gt;
      &lt;span class="p"&gt;}&lt;/span&gt;
    &lt;span class="p"&gt;});&lt;/span&gt;

    &lt;span class="c1"&gt;// List available resources&lt;/span&gt;
    &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;setRequestHandler&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;ListResourcesRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;async &lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;({&lt;/span&gt;
      &lt;span class="na"&gt;resources&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
        &lt;span class="p"&gt;{&lt;/span&gt;
          &lt;span class="na"&gt;uri&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;weather://cities&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Popular Cities&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="na"&gt;description&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;List of popular cities for weather queries&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="na"&gt;mimeType&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;application/json&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
        &lt;span class="p"&gt;}&lt;/span&gt;
      &lt;span class="p"&gt;]&lt;/span&gt;
    &lt;span class="p"&gt;}));&lt;/span&gt;

    &lt;span class="c1"&gt;// Read resources&lt;/span&gt;
    &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;setRequestHandler&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;ReadResourceRequestSchema&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="k"&gt;async &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
      &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;uri&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;params&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

      &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;uri&lt;/span&gt; &lt;span class="o"&gt;===&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;weather://cities&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;cities&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
          &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;London&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;New York&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Tokyo&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Paris&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Sydney&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
          &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Berlin&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Toronto&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Singapore&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Dubai&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Mumbai&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
        &lt;span class="p"&gt;];&lt;/span&gt;

        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
          &lt;span class="na"&gt;contents&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;
            &lt;span class="p"&gt;{&lt;/span&gt;
              &lt;span class="nx"&gt;uri&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
              &lt;span class="na"&gt;mimeType&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;application/json&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
              &lt;span class="na"&gt;text&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;JSON&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;stringify&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;cities&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="kc"&gt;null&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
            &lt;span class="p"&gt;}&lt;/span&gt;
          &lt;span class="p"&gt;]&lt;/span&gt;
        &lt;span class="p"&gt;};&lt;/span&gt;
      &lt;span class="p"&gt;}&lt;/span&gt;

      &lt;span class="k"&gt;throw&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="s2"&gt;`Unknown resource: &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;uri&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="p"&gt;});&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;

  &lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="nf"&gt;start&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;transport&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;StdioServerTransport&lt;/span&gt;&lt;span class="p"&gt;();&lt;/span&gt;
    &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;connect&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;transport&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="nx"&gt;console&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Weather MCP Server running on stdio&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Entry Point
&lt;/h3&gt;

&lt;p&gt;&lt;strong&gt;src/index.ts&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="nx"&gt;dotenv&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;dotenv&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;WeatherMCPServer&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;./server.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="nx"&gt;dotenv&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;config&lt;/span&gt;&lt;span class="p"&gt;();&lt;/span&gt;

&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;apiKey&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;process&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;env&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;OPENWEATHER_API_KEY&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="o"&gt;!&lt;/span&gt;&lt;span class="nx"&gt;apiKey&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;console&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Error: OPENWEATHER_API_KEY environment variable is required&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="nx"&gt;process&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;exit&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;server&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;WeatherMCPServer&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;apiKey&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
&lt;span class="nx"&gt;server&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;start&lt;/span&gt;&lt;span class="p"&gt;().&lt;/span&gt;&lt;span class="k"&gt;catch&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;=&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;console&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;error&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Server error:&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;error&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="nx"&gt;process&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;exit&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
&lt;span class="p"&gt;});&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Environment Configuration
&lt;/h3&gt;

&lt;p&gt;&lt;strong&gt;.env&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;OPENWEATHER_API_KEY=your_api_key_here
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Get a free API key from &lt;a href="https://openweathermap.org/api" rel="noopener noreferrer"&gt;OpenWeatherMap&lt;/a&gt;.&lt;/p&gt;

&lt;h2&gt;
  
  
  Connecting to Claude Desktop
&lt;/h2&gt;

&lt;p&gt;To use your MCP server with Claude Desktop, add it to your configuration:&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;MacOS&lt;/strong&gt;: &lt;code&gt;~/Library/Application Support/Claude/claude_desktop_config.json&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Windows&lt;/strong&gt;: &lt;code&gt;%APPDATA%\Claude\claude_desktop_config.json&lt;/code&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight json"&gt;&lt;code&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="nl"&gt;"mcpServers"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="nl"&gt;"weather"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="nl"&gt;"command"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"node"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="nl"&gt;"args"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="s2"&gt;"/absolute/path/to/weather-mcp-server/dist/index.js"&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="nl"&gt;"env"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="w"&gt;
        &lt;/span&gt;&lt;span class="nl"&gt;"OPENWEATHER_API_KEY"&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="s2"&gt;"your_api_key_here"&lt;/span&gt;&lt;span class="w"&gt;
      &lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
    &lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
  &lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="w"&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Restart Claude Desktop, and you'll see the weather tools available!&lt;/p&gt;

&lt;h2&gt;
  
  
  Testing Your Server
&lt;/h2&gt;

&lt;p&gt;Build and run the server:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;npm run build
npm start
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;You can test it with Claude Desktop or create a simple test client:&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;test-client.ts&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;Client&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@modelcontextprotocol/sdk/client/index.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="nx"&gt;StdioClientTransport&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;@modelcontextprotocol/sdk/client/stdio.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;testWeatherServer&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;transport&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;StdioClientTransport&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
    &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;node&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;args&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;dist/index.js&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt;
  &lt;span class="p"&gt;});&lt;/span&gt;

  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;client&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;Client&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
    &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;test-client&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;version&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;1.0.0&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;
  &lt;span class="p"&gt;},&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;capabilities&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{}&lt;/span&gt;
  &lt;span class="p"&gt;});&lt;/span&gt;

  &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;connect&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;transport&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;

  &lt;span class="c1"&gt;// List available tools&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;tools&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;listTools&lt;/span&gt;&lt;span class="p"&gt;();&lt;/span&gt;
  &lt;span class="nx"&gt;console&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;log&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Available tools:&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;tools&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;

  &lt;span class="c1"&gt;// Call weather tool&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;result&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="nx"&gt;client&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;callTool&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
    &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;get_current_weather&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;arguments&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;city&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;London&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt;
  &lt;span class="p"&gt;});&lt;/span&gt;

  &lt;span class="nx"&gt;console&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;log&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;Weather result:&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;result&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="nf"&gt;testWeatherServer&lt;/span&gt;&lt;span class="p"&gt;();&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Deploying to Production
&lt;/h2&gt;

&lt;h3&gt;
  
  
  Option 1: Docker Deployment
&lt;/h3&gt;

&lt;p&gt;&lt;strong&gt;Dockerfile&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight docker"&gt;&lt;code&gt;&lt;span class="k"&gt;FROM&lt;/span&gt;&lt;span class="s"&gt; node:18-alpine&lt;/span&gt;

&lt;span class="k"&gt;WORKDIR&lt;/span&gt;&lt;span class="s"&gt; /app&lt;/span&gt;

&lt;span class="k"&gt;COPY&lt;/span&gt;&lt;span class="s"&gt; package*.json ./&lt;/span&gt;
&lt;span class="k"&gt;RUN &lt;/span&gt;npm ci &lt;span class="nt"&gt;--only&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;production

&lt;span class="k"&gt;COPY&lt;/span&gt;&lt;span class="s"&gt; dist ./dist&lt;/span&gt;

&lt;span class="k"&gt;ENV&lt;/span&gt;&lt;span class="s"&gt; NODE_ENV=production&lt;/span&gt;

&lt;span class="k"&gt;CMD&lt;/span&gt;&lt;span class="s"&gt; ["node", "dist/index.js"]&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Option 2: Google Cloud Run
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight shell"&gt;&lt;code&gt;gcloud run deploy weather-mcp-server &lt;span class="se"&gt;\&lt;/span&gt;
  &lt;span class="nt"&gt;--source&lt;/span&gt; &lt;span class="nb"&gt;.&lt;/span&gt; &lt;span class="se"&gt;\&lt;/span&gt;
  &lt;span class="nt"&gt;--platform&lt;/span&gt; managed &lt;span class="se"&gt;\&lt;/span&gt;
  &lt;span class="nt"&gt;--region&lt;/span&gt; us-central1 &lt;span class="se"&gt;\&lt;/span&gt;
  &lt;span class="nt"&gt;--set-env-vars&lt;/span&gt; &lt;span class="nv"&gt;OPENWEATHER_API_KEY&lt;/span&gt;&lt;span class="o"&gt;=&lt;/span&gt;your_key
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Best Practices
&lt;/h2&gt;

&lt;ol&gt;
&lt;li&gt;
&lt;strong&gt;Error Handling&lt;/strong&gt;: Always wrap external API calls in try-catch blocks&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Validation&lt;/strong&gt;: Validate all input parameters before processing&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Rate Limiting&lt;/strong&gt;: Implement rate limiting for external API calls&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Caching&lt;/strong&gt;: Cache frequently requested data to reduce API costs&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Logging&lt;/strong&gt;: Use structured logging for debugging and monitoring&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Security&lt;/strong&gt;: Never expose API keys in code or version control&lt;/li&gt;
&lt;/ol&gt;

&lt;h2&gt;
  
  
  Advanced Features
&lt;/h2&gt;

&lt;h3&gt;
  
  
  Adding Authentication
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;private&lt;/span&gt; &lt;span class="nf"&gt;validateRequest&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;any&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt; &lt;span class="nx"&gt;boolean&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;token&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;request&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;params&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;_meta&lt;/span&gt;&lt;span class="p"&gt;?.&lt;/span&gt;&lt;span class="nx"&gt;authorization&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;token&lt;/span&gt; &lt;span class="o"&gt;===&lt;/span&gt; &lt;span class="nx"&gt;process&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;env&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;AUTH_TOKEN&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h3&gt;
  
  
  Implementing Caching
&lt;/h3&gt;



&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight typescript"&gt;&lt;code&gt;&lt;span class="k"&gt;import&lt;/span&gt; &lt;span class="nx"&gt;NodeCache&lt;/span&gt; &lt;span class="k"&gt;from&lt;/span&gt; &lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="s1"&gt;node-cache&lt;/span&gt;&lt;span class="dl"&gt;'&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="k"&gt;private&lt;/span&gt; &lt;span class="nx"&gt;cache&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;new&lt;/span&gt; &lt;span class="nc"&gt;NodeCache&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt; &lt;span class="na"&gt;stdTTL&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;600&lt;/span&gt; &lt;span class="p"&gt;});&lt;/span&gt; &lt;span class="c1"&gt;// 10 minutes&lt;/span&gt;

&lt;span class="k"&gt;async&lt;/span&gt; &lt;span class="nf"&gt;getCachedWeather&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;city&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="kr"&gt;string&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt; &lt;span class="nb"&gt;Promise&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nx"&gt;WeatherData&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;cacheKey&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;`weather:&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;city&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;cached&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;cache&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="kd"&gt;get&lt;/span&gt;&lt;span class="o"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nx"&gt;WeatherData&lt;/span&gt;&lt;span class="o"&gt;&amp;gt;&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;cacheKey&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;

  &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;cached&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;cached&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;weather&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="k"&gt;await&lt;/span&gt; &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;weatherService&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;getCurrentWeather&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;city&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="k"&gt;this&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;cache&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;set&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;cacheKey&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="nx"&gt;weather&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;

  &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="nx"&gt;weather&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;h2&gt;
  
  
  Troubleshooting
&lt;/h2&gt;

&lt;h3&gt;
  
  
  Common Issues
&lt;/h3&gt;

&lt;p&gt;&lt;strong&gt;Server not appearing in Claude Desktop&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Verify the path in &lt;code&gt;claude_desktop_config.json&lt;/code&gt; is absolute&lt;/li&gt;
&lt;li&gt;Check that the build succeeded (&lt;code&gt;npm run build&lt;/code&gt;)&lt;/li&gt;
&lt;li&gt;Restart Claude Desktop completely&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;API errors&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Confirm your OpenWeather API key is valid&lt;/li&gt;
&lt;li&gt;Check rate limits on your API tier&lt;/li&gt;
&lt;li&gt;Verify network connectivity&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;TypeScript errors&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Ensure all dependencies are installed&lt;/li&gt;
&lt;li&gt;Run &lt;code&gt;npm run build&lt;/code&gt; to check for compilation errors&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  Conclusion
&lt;/h2&gt;

&lt;p&gt;You've now built a complete MCP server that can integrate with any MCP-compatible client. This weather server demonstrates the core concepts:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Tool definition and execution&lt;/li&gt;
&lt;li&gt;Resource management&lt;/li&gt;
&lt;li&gt;Error handling&lt;/li&gt;
&lt;li&gt;Client integration&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;The same patterns can be extended to build MCP servers for:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Database access&lt;/li&gt;
&lt;li&gt;File system operations&lt;/li&gt;
&lt;li&gt;API integrations&lt;/li&gt;
&lt;li&gt;Business tool automation&lt;/li&gt;
&lt;li&gt;Custom workflows&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  Next Steps
&lt;/h2&gt;

&lt;ol&gt;
&lt;li&gt;
&lt;strong&gt;Extend functionality&lt;/strong&gt;: Add more weather features (air quality, UV index, alerts)&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Add tests&lt;/strong&gt;: Implement unit and integration tests&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Monitor performance&lt;/strong&gt;: Add metrics and logging&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Build a remote server&lt;/strong&gt;: Convert to HTTP-based MCP server for multiple clients&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Create documentation&lt;/strong&gt;: Document your API for other developers&lt;/li&gt;
&lt;/ol&gt;

&lt;h2&gt;
  
  
  Resources
&lt;/h2&gt;

&lt;ul&gt;
&lt;li&gt;&lt;a href="https://modelcontextprotocol.io" rel="noopener noreferrer"&gt;MCP Official Documentation&lt;/a&gt;&lt;/li&gt;
&lt;li&gt;&lt;a href="https://openweathermap.org/api" rel="noopener noreferrer"&gt;OpenWeather API Docs&lt;/a&gt;&lt;/li&gt;
&lt;/ul&gt;

</description>
      <category>tutorial</category>
      <category>programming</category>
      <category>beginners</category>
      <category>ai</category>
    </item>
    <item>
      <title>🚀 CI/CD Testing Tools Comparison: GitHub Actions vs GitLab CI vs Jenkins (With Real Examples!)</title>
      <dc:creator>Diego Fernando Castillo Mamani</dc:creator>
      <pubDate>Sun, 30 Nov 2025 06:12:56 +0000</pubDate>
      <link>https://dev.to/diegocastillo12/testing-management-tools-a-comprehensive-comparison-with-real-world-examples-5930</link>
      <guid>https://dev.to/diegocastillo12/testing-management-tools-a-comprehensive-comparison-with-real-world-examples-5930</guid>
      <description>&lt;h2&gt;
  
  
  📋 Introducción
&lt;/h2&gt;

&lt;p&gt;Las herramientas de testing automatizado son fundamentales en el desarrollo moderno. Este artículo compara las principales plataformas CI/CD con ejemplos prácticos y código real.&lt;/p&gt;




&lt;h2&gt;
  
  
  🔧 Herramientas Analizadas
&lt;/h2&gt;

&lt;h3&gt;
  
  
  1️⃣ GitHub Actions
&lt;/h3&gt;

&lt;p&gt;&lt;strong&gt;¿Qué es?&lt;/strong&gt; Plataforma CI/CD nativa de GitHub&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;✨ Características Principales:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Integración nativa con repositorios GitHub&lt;/li&gt;
&lt;li&gt;Marketplace con miles de actions predefinidas&lt;/li&gt;
&lt;li&gt;Matrix builds para múltiples entornos&lt;/li&gt;
&lt;li&gt;2,000 minutos gratis/mes&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;💻 Ejemplo Real:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# .github/workflows/test.yml&lt;/span&gt;
&lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Run Tests&lt;/span&gt;

&lt;span class="na"&gt;on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;push&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;branches&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt; &lt;span class="nv"&gt;main&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;develop&lt;/span&gt; &lt;span class="pi"&gt;]&lt;/span&gt;
  &lt;span class="na"&gt;pull_request&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;branches&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt; &lt;span class="nv"&gt;main&lt;/span&gt; &lt;span class="pi"&gt;]&lt;/span&gt;

&lt;span class="na"&gt;jobs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;test&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;runs-on&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;ubuntu-latest&lt;/span&gt;

    &lt;span class="na"&gt;strategy&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;matrix&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="na"&gt;node-version&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;[&lt;/span&gt;&lt;span class="nv"&gt;16.x&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;18.x&lt;/span&gt;&lt;span class="pi"&gt;,&lt;/span&gt; &lt;span class="nv"&gt;20.x&lt;/span&gt;&lt;span class="pi"&gt;]&lt;/span&gt;

    &lt;span class="na"&gt;steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/checkout@v3&lt;/span&gt;

    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Setup Node.js ${{ matrix.node-version }}&lt;/span&gt;
      &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;actions/setup-node@v3&lt;/span&gt;
      &lt;span class="na"&gt;with&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="na"&gt;node-version&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;${{ matrix.node-version }}&lt;/span&gt;
        &lt;span class="na"&gt;cache&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;npm'&lt;/span&gt;

    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Install dependencies&lt;/span&gt;
      &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npm ci&lt;/span&gt;

    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Run tests&lt;/span&gt;
      &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npm test -- --coverage&lt;/span&gt;

    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Upload coverage&lt;/span&gt;
      &lt;span class="na"&gt;uses&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;codecov/codecov-action@v3&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;🎯 Mejor Para:&lt;/strong&gt; Proyectos en GitHub que necesitan integración simple y rápida&lt;/p&gt;




&lt;h3&gt;
  
  
  2️⃣ GitLab CI/CD
&lt;/h3&gt;

&lt;p&gt;&lt;strong&gt;¿Qué es?&lt;/strong&gt; Plataforma DevOps completa con CI/CD integrado&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;✨ Características Principales:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Plataforma todo-en-uno&lt;/li&gt;
&lt;li&gt;Auto DevOps para configuración automática&lt;/li&gt;
&lt;li&gt;Container registry incluido&lt;/li&gt;
&lt;li&gt;Visualización potente de pipelines&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;💻 Ejemplo Real:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# .gitlab-ci.yml&lt;/span&gt;
&lt;span class="na"&gt;stages&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;build&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;test&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;deploy&lt;/span&gt;

&lt;span class="na"&gt;variables&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;POSTGRES_DB&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;test_db&lt;/span&gt;

&lt;span class="na"&gt;build&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;stage&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;build&lt;/span&gt;
  &lt;span class="na"&gt;image&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;node:18&lt;/span&gt;
  &lt;span class="na"&gt;script&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;npm install&lt;/span&gt;
  &lt;span class="na"&gt;artifacts&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;paths&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;node_modules/&lt;/span&gt;
    &lt;span class="na"&gt;expire_in&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;1 hour&lt;/span&gt;

&lt;span class="na"&gt;unit_tests&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;stage&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;test&lt;/span&gt;
  &lt;span class="na"&gt;image&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;node:18&lt;/span&gt;
  &lt;span class="na"&gt;dependencies&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;build&lt;/span&gt;
  &lt;span class="na"&gt;script&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;npm run test:unit&lt;/span&gt;
  &lt;span class="na"&gt;coverage&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;/Lines\s*:\s*(\d+\.\d+)%/'&lt;/span&gt;
  &lt;span class="na"&gt;artifacts&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;reports&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="na"&gt;junit&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;junit.xml&lt;/span&gt;
      &lt;span class="na"&gt;coverage_report&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
        &lt;span class="na"&gt;coverage_format&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;cobertura&lt;/span&gt;
        &lt;span class="na"&gt;path&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;coverage/cobertura-coverage.xml&lt;/span&gt;

&lt;span class="na"&gt;integration_tests&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;stage&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;test&lt;/span&gt;
  &lt;span class="na"&gt;image&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;node:18&lt;/span&gt;
  &lt;span class="na"&gt;services&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;postgres:14&lt;/span&gt;
  &lt;span class="na"&gt;script&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;npm run test:integration&lt;/span&gt;
  &lt;span class="na"&gt;only&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;merge_requests&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;main&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;🎯 Mejor Para:&lt;/strong&gt; Equipos que usan GitLab y necesitan una solución DevOps completa&lt;/p&gt;




&lt;h3&gt;
  
  
  3️⃣ Jenkins
&lt;/h3&gt;

&lt;p&gt;&lt;strong&gt;¿Qué es?&lt;/strong&gt; Servidor de automatización open-source con máxima customización&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;✨ Características Principales:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;1800+ plugins disponibles&lt;/li&gt;
&lt;li&gt;Auto-hospedado con control total&lt;/li&gt;
&lt;li&gt;Builds distribuidos&lt;/li&gt;
&lt;li&gt;Comunidad masiva&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;💻 Ejemplo Real:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight groovy"&gt;&lt;code&gt;&lt;span class="c1"&gt;// Jenkinsfile&lt;/span&gt;
&lt;span class="n"&gt;pipeline&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
    &lt;span class="n"&gt;agent&lt;/span&gt; &lt;span class="n"&gt;any&lt;/span&gt;

    &lt;span class="n"&gt;tools&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="n"&gt;nodejs&lt;/span&gt; &lt;span class="s1"&gt;'NodeJS-18'&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;

    &lt;span class="n"&gt;environment&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="n"&gt;CI&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="s1"&gt;'true'&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;

    &lt;span class="n"&gt;stages&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="n"&gt;stage&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s1"&gt;'Checkout'&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
            &lt;span class="n"&gt;steps&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
                &lt;span class="n"&gt;checkout&lt;/span&gt; &lt;span class="n"&gt;scm&lt;/span&gt;
            &lt;span class="o"&gt;}&lt;/span&gt;
        &lt;span class="o"&gt;}&lt;/span&gt;

        &lt;span class="n"&gt;stage&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s1"&gt;'Install'&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
            &lt;span class="n"&gt;steps&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
                &lt;span class="n"&gt;sh&lt;/span&gt; &lt;span class="s1"&gt;'npm ci'&lt;/span&gt;
            &lt;span class="o"&gt;}&lt;/span&gt;
        &lt;span class="o"&gt;}&lt;/span&gt;

        &lt;span class="n"&gt;stage&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s1"&gt;'Test'&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
            &lt;span class="n"&gt;steps&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
                &lt;span class="n"&gt;sh&lt;/span&gt; &lt;span class="s1"&gt;'npm test -- --ci'&lt;/span&gt;
            &lt;span class="o"&gt;}&lt;/span&gt;
            &lt;span class="n"&gt;post&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
                &lt;span class="n"&gt;always&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
                    &lt;span class="n"&gt;junit&lt;/span&gt; &lt;span class="s1"&gt;'test-results/junit.xml'&lt;/span&gt;
                &lt;span class="o"&gt;}&lt;/span&gt;
            &lt;span class="o"&gt;}&lt;/span&gt;
        &lt;span class="o"&gt;}&lt;/span&gt;

        &lt;span class="n"&gt;stage&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s1"&gt;'Coverage'&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
            &lt;span class="n"&gt;steps&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
                &lt;span class="n"&gt;sh&lt;/span&gt; &lt;span class="s1"&gt;'npm run test:coverage'&lt;/span&gt;
            &lt;span class="o"&gt;}&lt;/span&gt;
            &lt;span class="n"&gt;post&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
                &lt;span class="n"&gt;always&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
                    &lt;span class="n"&gt;publishCoverage&lt;/span&gt; &lt;span class="nl"&gt;adapters:&lt;/span&gt; &lt;span class="o"&gt;[&lt;/span&gt;
                        &lt;span class="n"&gt;coberturaAdapter&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="s1"&gt;'coverage/cobertura-coverage.xml'&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt;
                    &lt;span class="o"&gt;]&lt;/span&gt;
                &lt;span class="o"&gt;}&lt;/span&gt;
            &lt;span class="o"&gt;}&lt;/span&gt;
        &lt;span class="o"&gt;}&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;

    &lt;span class="n"&gt;post&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
        &lt;span class="n"&gt;failure&lt;/span&gt; &lt;span class="o"&gt;{&lt;/span&gt;
            &lt;span class="n"&gt;emailext&lt;/span&gt; &lt;span class="o"&gt;(&lt;/span&gt;
                &lt;span class="nl"&gt;subject:&lt;/span&gt; &lt;span class="s2"&gt;"Build Failed: ${env.JOB_NAME}"&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt;
                &lt;span class="nl"&gt;body:&lt;/span&gt; &lt;span class="s2"&gt;"Check: ${env.BUILD_URL}"&lt;/span&gt;&lt;span class="o"&gt;,&lt;/span&gt;
                &lt;span class="nl"&gt;to:&lt;/span&gt; &lt;span class="s2"&gt;"${env.CHANGE_AUTHOR_EMAIL}"&lt;/span&gt;
            &lt;span class="o"&gt;)&lt;/span&gt;
        &lt;span class="o"&gt;}&lt;/span&gt;
    &lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="o"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;🎯 Mejor Para:&lt;/strong&gt; Empresas que necesitan customización extrema e infraestructura propia&lt;/p&gt;




&lt;h3&gt;
  
  
  4️⃣ CircleCI
&lt;/h3&gt;

&lt;p&gt;&lt;strong&gt;¿Qué es?&lt;/strong&gt; Plataforma cloud reconocida por su velocidad&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;✨ Características Principales:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Builds súper rápidos&lt;/li&gt;
&lt;li&gt;Caching inteligente&lt;/li&gt;
&lt;li&gt;Soporte Docker nativo&lt;/li&gt;
&lt;li&gt;Analytics poderosos&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;💻 Ejemplo Real:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# .circleci/config.yml&lt;/span&gt;
&lt;span class="na"&gt;version&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;2.1&lt;/span&gt;

&lt;span class="na"&gt;orbs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;node&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;circleci/node@5.1.0&lt;/span&gt;

&lt;span class="na"&gt;executors&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;node-executor&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;docker&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;image&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;cimg/node:18.17&lt;/span&gt;

&lt;span class="na"&gt;jobs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;test&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;executor&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;node-executor&lt;/span&gt;
    &lt;span class="na"&gt;parallelism&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;4&lt;/span&gt;
    &lt;span class="na"&gt;steps&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;checkout&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;restore_cache&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;keys&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
            &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;v1-deps-{{ checksum "package-lock.json" }}&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Install&lt;/span&gt;
          &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;npm ci&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;save_cache&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;paths&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
            &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;node_modules&lt;/span&gt;
          &lt;span class="na"&gt;key&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;v1-deps-{{ checksum "package-lock.json" }}&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;run&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Run tests&lt;/span&gt;
          &lt;span class="na"&gt;command&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
            &lt;span class="s"&gt;FILES=$(circleci tests glob "src/**/*.test.js" | \&lt;/span&gt;
                    &lt;span class="s"&gt;circleci tests split --split-by=timings)&lt;/span&gt;
            &lt;span class="s"&gt;npm test -- $FILES --coverage&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="na"&gt;store_test_results&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
          &lt;span class="na"&gt;path&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;test-results&lt;/span&gt;

&lt;span class="na"&gt;workflows&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;test-workflow&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;jobs&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
      &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;test&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;🎯 Mejor Para:&lt;/strong&gt; Teams que priorizan velocidad y ejecución paralela&lt;/p&gt;




&lt;h3&gt;
  
  
  5️⃣ Travis CI
&lt;/h3&gt;

&lt;p&gt;&lt;strong&gt;¿Qué es?&lt;/strong&gt; CI/CD clásico, popular en open-source&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;✨ Características Principales:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Configuración YAML simple&lt;/li&gt;
&lt;li&gt;Gratis para proyectos open-source&lt;/li&gt;
&lt;li&gt;Multi-lenguaje&lt;/li&gt;
&lt;li&gt;Build matrix&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;💻 Ejemplo Real:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="c1"&gt;# .travis.yml&lt;/span&gt;
&lt;span class="na"&gt;language&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;node_js&lt;/span&gt;

&lt;span class="na"&gt;node_js&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;16'&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;18'&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s1"&gt;'&lt;/span&gt;&lt;span class="s"&gt;20'&lt;/span&gt;

&lt;span class="na"&gt;services&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;postgresql&lt;/span&gt;

&lt;span class="na"&gt;env&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;global&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;DATABASE_URL=postgresql://postgres@localhost/test_db&lt;/span&gt;
  &lt;span class="na"&gt;matrix&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;TEST_SUITE=unit&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;TEST_SUITE=integration&lt;/span&gt;

&lt;span class="na"&gt;cache&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;directories&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;node_modules&lt;/span&gt;

&lt;span class="na"&gt;before_script&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;psql -c 'create database test_db;' -U postgres&lt;/span&gt;

&lt;span class="na"&gt;script&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;npm run lint&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="pi"&gt;|&lt;/span&gt;
    &lt;span class="s"&gt;if [ "$TEST_SUITE" = "unit" ]; then&lt;/span&gt;
      &lt;span class="s"&gt;npm run test:unit -- --coverage&lt;/span&gt;
    &lt;span class="s"&gt;else&lt;/span&gt;
      &lt;span class="s"&gt;npm run test:integration&lt;/span&gt;
    &lt;span class="s"&gt;fi&lt;/span&gt;

&lt;span class="na"&gt;after_success&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;npm run coverage:upload&lt;/span&gt;

&lt;span class="na"&gt;notifications&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;email&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="na"&gt;on_success&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;change&lt;/span&gt;
    &lt;span class="na"&gt;on_failure&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;always&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;🎯 Mejor Para:&lt;/strong&gt; Proyectos open-source y equipos que buscan simplicidad&lt;/p&gt;

&lt;h2&gt;
  
  
  💡 Best Practices
&lt;/h2&gt;

&lt;p&gt;&lt;strong&gt;1. 🔺 Pirámide de Testing&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Más tests unitarios&lt;/li&gt;
&lt;li&gt;Menos tests de integración&lt;/li&gt;
&lt;li&gt;Mínimos tests E2E&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;2. ⚡ Optimización&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Cachear dependencias&lt;/li&gt;
&lt;li&gt;Ejecutar en paralelo&lt;/li&gt;
&lt;li&gt;Fail fast cuando sea posible&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;3. 📈 Cobertura&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Monitorear tendencias&lt;/li&gt;
&lt;li&gt;Apuntar a 80%+ en crítico&lt;/li&gt;
&lt;li&gt;No sacrificar calidad por %&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;4. 🔒 Seguridad&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Usar secrets para credenciales&lt;/li&gt;
&lt;li&gt;Escanear dependencias&lt;/li&gt;
&lt;li&gt;Actualizar regularmente&lt;/li&gt;
&lt;/ul&gt;




&lt;h2&gt;
  
  
  🎬 Repositorio de Ejemplo
&lt;/h2&gt;

&lt;p&gt;He creado un repositorio completo con ejemplos funcionales:&lt;/p&gt;

&lt;p&gt;📦 &lt;strong&gt;Repo:&lt;/strong&gt; &lt;code&gt;github.com/your-user/ci-cd-testing-comparison&lt;/code&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Incluye:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;✅ API Node.js con Express&lt;/li&gt;
&lt;li&gt;✅ Tests unitarios (Jest)&lt;/li&gt;
&lt;li&gt;✅ Tests de integración (Supertest)&lt;/li&gt;
&lt;li&gt;✅ Tests E2E (Playwright)&lt;/li&gt;
&lt;li&gt;✅ Configuraciones para todas las plataformas&lt;/li&gt;
&lt;li&gt;✅ Docker setup&lt;/li&gt;
&lt;li&gt;✅ Documentación completa&lt;/li&gt;
&lt;/ul&gt;




&lt;h2&gt;
  
  
  🎯 ¿Cuál Elegir?
&lt;/h2&gt;

&lt;p&gt;&lt;strong&gt;Elige GitHub Actions si:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Ya usas GitHub&lt;/li&gt;
&lt;li&gt;Quieres setup rápido&lt;/li&gt;
&lt;li&gt;Necesitas gran ecosistema&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;Elige GitLab CI/CD si:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Quieres plataforma todo-en-uno&lt;/li&gt;
&lt;li&gt;Necesitas self-hosting&lt;/li&gt;
&lt;li&gt;Buscas DevOps completo&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;Elige Jenkins si:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Necesitas control total&lt;/li&gt;
&lt;li&gt;Tienes infraestructura propia&lt;/li&gt;
&lt;li&gt;Requieres customización extrema&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;Elige CircleCI si:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Velocidad es prioridad&lt;/li&gt;
&lt;li&gt;Necesitas paralelismo avanzado&lt;/li&gt;
&lt;li&gt;Quieres analytics detallados&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;strong&gt;Elige Travis CI si:&lt;/strong&gt;&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Proyecto open-source&lt;/li&gt;
&lt;li&gt;Buscas simplicidad máxima&lt;/li&gt;
&lt;li&gt;Configuración mínima&lt;/li&gt;
&lt;/ul&gt;




&lt;h2&gt;
  
  
  🚀 Conclusión
&lt;/h2&gt;

&lt;p&gt;No existe una solución única para todos. La elección depende de tu stack, equipo, presupuesto y necesidades específicas. Todas estas herramientas son excelentes cuando se usan correctamente.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Pro tip:&lt;/strong&gt; Empieza simple, itera y optimiza según tus necesidades reales.&lt;/p&gt;




&lt;h2&gt;
  
  
  📚 Recursos Adicionales
&lt;/h2&gt;

&lt;ul&gt;
&lt;li&gt;📖 &lt;a href="https://docs.github.com/actions" rel="noopener noreferrer"&gt;GitHub Actions Docs&lt;/a&gt;
&lt;/li&gt;
&lt;li&gt;📖 &lt;a href="https://docs.gitlab.com/ee/ci/" rel="noopener noreferrer"&gt;GitLab CI/CD Docs&lt;/a&gt;
&lt;/li&gt;
&lt;li&gt;📖 &lt;a href="https://www.jenkins.io/doc/" rel="noopener noreferrer"&gt;Jenkins Docs&lt;/a&gt;
&lt;/li&gt;
&lt;li&gt;📖 &lt;a href="https://circleci.com/docs/" rel="noopener noreferrer"&gt;CircleCI Docs&lt;/a&gt;
&lt;/li&gt;
&lt;li&gt;📖 &lt;a href="https://docs.travis-ci.com/" rel="noopener noreferrer"&gt;Travis CI Docs&lt;/a&gt;
&lt;/li&gt;
&lt;/ul&gt;




&lt;p&gt;&lt;strong&gt;🏷️ Tags:&lt;/strong&gt; #DevOps #CICD #Testing #Automation #GitHubActions #GitLab #Jenkins #CircleCI #TravisCI #QualityAssurance&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;👤 Autor:&lt;/strong&gt; [Diego Fernando Castillo Mamani] | 📅 Fecha: Noviembre 2024&lt;/p&gt;

</description>
      <category>testing</category>
      <category>cicd</category>
      <category>github</category>
      <category>devops</category>
    </item>
    <item>
      <title>Interactive Data Visualization: Streamlit, Dash, and Bokeh</title>
      <dc:creator>Diego Fernando Castillo Mamani</dc:creator>
      <pubDate>Mon, 15 Sep 2025 04:09:25 +0000</pubDate>
      <link>https://dev.to/diegocastillo12/interactive-data-visualization-streamlit-dash-and-bokeh-13ba</link>
      <guid>https://dev.to/diegocastillo12/interactive-data-visualization-streamlit-dash-and-bokeh-13ba</guid>
      <description>&lt;p&gt;&lt;strong&gt;Introduction&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;Modern data analysis requires interactive visualizations that allow users to explore data dynamically. Today we'll explore three powerful Python libraries: Streamlit, Dash, and Bokeh - each offering unique advantages for different use cases.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;🚀 Streamlit: Simple and Fast&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;Streamlit is perfect for rapid prototyping with minimal code. It's the go-to choice for data scientists who want to create web apps without web development knowledge.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Key Features&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;✅ Zero HTML/CSS knowledge required&lt;br&gt;
✅ Real-time updates&lt;br&gt;
✅ Easy deployment&lt;br&gt;
✅ Rich widget ecosystem&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Example: Sales Dashboard&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;import streamlit as st
import pandas as pd
import plotly.express as px
import numpy as np


# Page configuration
st.set_page_config(page_title="Sales Dashboard", layout="wide")
st.title("📊 Sales Dashboard")

# Generate sample data
@st.cache_data
def load_data():
    dates = pd.date_range('2024-01-01', '2024-12-31', freq='D')
    data = {
        'date': dates,
        'sales': np.random.normal(1000, 200, len(dates)),
        'region': np.random.choice(['North', 'South', 'East', 'West'], len(dates)),
        'product': np.random.choice(['Product A', 'Product B', 'Product C'], len(dates))
    }
    df = pd.DataFrame(data)
    df['sales'] = df['sales'].clip(lower=0)  # No negative sales
    return df

df = load_data()

# Sidebar filters
st.sidebar.header("Filters")
region = st.sidebar.selectbox("Select Region", df['region'].unique())
product = st.sidebar.selectbox("Select Product", df['product'].unique())

# Filter data
filtered_df = df[(df['region'] == region) &amp;amp; (df['product'] == product)]

# Metrics row
col1, col2, col3 = st.columns(3)
with col1:
    st.metric("Total Sales", f"${filtered_df['sales'].sum():,.2f}")
with col2:
    st.metric("Average Daily Sales", f"${filtered_df['sales'].mean():.2f}")
with col3:
    st.metric("Number of Days", len(filtered_df))

# Charts
col1, col2 = st.columns(2)

with col1:
    # Time series chart
    fig_line = px.line(
        filtered_df, 
        x='date', 
        y='sales', 
        title=f"Sales Trend - {region} ({product})"
    )
    st.plotly_chart(fig_line, use_container_width=True)

with col2:
    # Distribution chart
    fig_hist = px.histogram(
        filtered_df, 
        x='sales', 
        title="Sales Distribution",
        nbins=30
    )
    st.plotly_chart(fig_hist, use_container_width=True)

# Data table
if st.checkbox("Show Raw Data"):
    st.subheader("Raw Data")
    st.dataframe(filtered_df.head(100), use_container_width=True)

&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;🏢 Dash: Enterprise-Ready&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;Dash offers more control and customization for production applications. It's built on Flask and React, making it perfect for enterprise-grade dashboards.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Key Features&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;✅ Production-ready&lt;br&gt;
✅ Highly customizable&lt;br&gt;
✅ Advanced callback system&lt;br&gt;
✅ Enterprise authentication support&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Example: Stock Portfolio Tracker&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;import dash
from dash import dcc, html, Input, Output, callback
import plotly.express as px
import plotly.graph_objects as go
import pandas as pd
import yfinance as yf

# Initialize the Dash app
app = dash.Dash(__name__)

# Portfolio data
STOCKS = ['AAPL', 'GOOGL', 'TSLA', 'MSFT', 'AMZN']

# Layout
app.layout = html.Div([
    html.Div([
        html.H1("💼 Stock Portfolio Tracker", 
                style={'textAlign': 'center', 'color': '#2E86AB', 'marginBottom': 30}),
    ]),

    html.Div([
        html.Div([
            html.Label("Select Stock:", style={'fontWeight': 'bold'}),
            dcc.Dropdown(
                id='stock-dropdown',
                options=[{'label': stock, 'value': stock} for stock in STOCKS],
                value='AAPL',
                style={'marginBottom': 20}
            ),

            html.Label("Time Period:", style={'fontWeight': 'bold'}),
            dcc.Dropdown(
                id='period-dropdown',
                options=[
                    {'label': '1 Month', 'value': '1mo'},
                    {'label': '3 Months', 'value': '3mo'},
                    {'label': '6 Months', 'value': '6mo'},
                    {'label': '1 Year', 'value': '1y'}
                ],
                value='3mo'
            )
        ], style={'width': '30%', 'display': 'inline-block', 'verticalAlign': 'top'}),

        html.Div([
            html.Div(id='stock-info')
        ], style={'width': '70%', 'display': 'inline-block', 'paddingLeft': 20})
    ]),

    html.Div([
        dcc.Graph(id='stock-chart')
    ]),

    html.Div([
        dcc.Graph(id='volume-chart')
    ])
])

@app.callback(
    [Output('stock-chart', 'figure'),
     Output('volume-chart', 'figure'),
     Output('stock-info', 'children')],
    [Input('stock-dropdown', 'value'),
     Input('period-dropdown', 'value')]
)
def update_dashboard(selected_stock, period):
    # Fetch stock data
    try:
        stock_data = yf.download(selected_stock, period=period)

        # Stock price chart
        fig_price = go.Figure()
        fig_price.add_trace(go.Candlestick(
            x=stock_data.index,
            open=stock_data['Open'],
            high=stock_data['High'],
            low=stock_data['Low'],
            close=stock_data['Close'],
            name=selected_stock
        ))
        fig_price.update_layout(
            title=f"{selected_stock} Stock Price",
            yaxis_title="Price ($)",
            xaxis_title="Date"
        )

        # Volume chart
        fig_volume = px.bar(
            x=stock_data.index,
            y=stock_data['Volume'],
            title=f"{selected_stock} Trading Volume"
        )

        # Stock info
        current_price = stock_data['Close'].iloc[-1]
        price_change = current_price - stock_data['Close'].iloc[-2]
        price_change_pct = (price_change / stock_data['Close'].iloc[-2]) * 100

        info = html.Div([
            html.H3(f"{selected_stock} Information"),
            html.P(f"Current Price: ${current_price:.2f}"),
            html.P(f"Change: ${price_change:.2f} ({price_change_pct:.2f}%)",
                   style={'color': 'green' if price_change &amp;gt;= 0 else 'red'}),
            html.P(f"Period High: ${stock_data['High'].max():.2f}"),
            html.P(f"Period Low: ${stock_data['Low'].min():.2f}")
        ])

        return fig_price, fig_volume, info

    except Exception as e:
        # Error handling
        empty_fig = go.Figure()
        error_info = html.P(f"Error loading data: {str(e)}")
        return empty_fig, empty_fig, error_info

if __name__ == '__main__':
    app.run_server(debug=True)
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;⚡ Bokeh: Advanced Visualizations&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;Bokeh handles large datasets and complex interactions efficiently. It's perfect for creating sophisticated, publication-ready visualizations.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Key Features&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;✅ High performance with large datasets&lt;br&gt;
✅ Advanced interactions&lt;br&gt;
✅ Real-time capabilities&lt;br&gt;
✅ Server and standalone applications&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Example: Real-time Data Monitor&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;from bokeh.plotting import figure, curdoc
from bokeh.layouts import column, row
from bokeh.models import ColumnDataSource, Select, Button
from bokeh.models.widgets import DataTable, TableColumn
import numpy as np
import pandas as pd
from datetime import datetime
from functools import partial

# Global data source
source = ColumnDataSource(data=dict(
    x=[], y=[], timestamp=[], sensor_id=[], color=[]
))

# Create main plot
def create_time_plot():
    p = figure(
        title="Real-time Sensor Data Monitor",
        x_axis_label="Time",
        y_axis_label="Value",
        width=800,
        height=400,
        x_axis_type='datetime'
    )

    p.line('timestamp', 'y', source=source, line_width=2, color='blue', alpha=0.8)
    p.circle('timestamp', 'y', source=source, size=8, color='color', alpha=0.6)

    return p

# Create histogram
def create_histogram():
    p = figure(
        title="Value Distribution",
        x_axis_label="Value",
        y_axis_label="Frequency",
        width=400,
        height=300
    )

    return p

# Controls
sensor_select = Select(
    title="Sensor ID:", 
    value="All", 
    options=["All", "Sensor_1", "Sensor_2", "Sensor_3"]
)

start_button = Button(label="Start Monitoring", button_type="success")
stop_button = Button(label="Stop Monitoring", button_type="danger")

# Data table
columns = [
    TableColumn(field="timestamp", title="Timestamp"),
    TableColumn(field="y", title="Value"),
    TableColumn(field="sensor_id", title="Sensor ID")
]
data_table = DataTable(source=source, columns=columns, width=400, height=200)

# Callback for data generation
def update_data():
    """Generate new data point"""
    sensors = ["Sensor_1", "Sensor_2", "Sensor_3"]
    colors = ["red", "blue", "green"]

    new_data = {
        'timestamp': [datetime.now()],
        'y': [np.random.normal(50, 10)],
        'sensor_id': [np.random.choice(sensors)],
        'color': [np.random.choice(colors)]
    }

    # Update data source
    current_data = source.data.copy()
    for key in new_data:
        if key in current_data:
            current_data[key].extend(new_data[key])
            # Keep only last 100 points
            if len(current_data[key]) &amp;gt; 100:
                current_data[key] = current_data[key][-100:]
        else:
            current_data[key] = new_data[key]

    source.data = current_data

# Button callbacks
def start_monitoring():
    curdoc().add_periodic_callback(update_data, 1000)

def stop_monitoring():
    curdoc().remove_periodic_callback(update_data)

start_button.on_click(start_monitoring)
stop_button.on_click(stop_monitoring)

# Create plots
time_plot = create_time_plot()
histogram = create_histogram()

# Layout
controls = column(sensor_select, row(start_button, stop_button))
plots = row(time_plot, column(histogram, data_table))
layout = column(controls, plots)

# Add to document
curdoc().add_root(layout)
curdoc().title = "Real-time Data Monitor"
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;📦 Deployment Guide&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Streamlit Cloud (Recommended)&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Create requirements.txt:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;txtstreamlit==1.28.0
pandas==2.0.3
plotly==5.15.0
numpy==1.24.3
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Deploy Steps:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;# Push to GitHub
git add .
git commit -m "Initial commit"
git push origin main

# Visit share.streamlit.io
# Connect your GitHub repository
# Auto-deploy!
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Dash on Heroku&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Prepare files:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;# Add to your Dash app
server = app.server

if __name__ == '__main__':
    app.run_server(debug=False)
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Create Procfile:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;web: gunicorn app:server
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;Deploy:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;heroku create your-app-name
git push heroku main
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;*&lt;em&gt;**Bokeh Server&lt;/em&gt;*&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Start Bokeh server:&lt;/strong&gt;**&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;bashbokeh serve --show --allow-websocket-origin=yourdomain.com app.py
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;For cloud deployment:&lt;/strong&gt;&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight plaintext"&gt;&lt;code&gt;bashbokeh serve --port=$PORT --allow-websocket-origin=* app.py
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;strong&gt;📊 Comparison Matrix&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;&lt;a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Frdv0qg2axq81t08hh6fn.png" class="article-body-image-wrapper"&gt;&lt;img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Frdv0qg2axq81t08hh6fn.png" alt=" " width="800" height="151"&gt;&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;Conclusion&lt;/strong&gt;&lt;/p&gt;

&lt;p&gt;Interactive data visualization has never been more accessible. Whether you choose Streamlit for rapid prototyping, Dash for enterprise applications, or Bokeh for advanced visualizations, you now have the power to create compelling, interactive dashboards that transform how users interact with data.&lt;br&gt;
Start with Streamlit to get your feet wet, graduate to Dash when you need production features, and leverage Bokeh when performance and advanced interactions are critical.&lt;br&gt;
The future of data visualization is interactive - and these tools are your gateway to that future.&lt;/p&gt;

</description>
      <category>datascience</category>
      <category>python</category>
      <category>webdev</category>
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