I built a free AI prompt API with 185 expert roles and MCP support

#ai #api #mcp #opensource

I got tired of writing the same prompt patterns over and over — "act as a senior software engineer," "you are an expert financial analyst," etc. So I built an API with 185 pre-built expert roles and 1,741 prompt templates, and made it free.

What it is

GODLE is a free, static JSON API that gives you structured prompt templates for 185 professional roles across 24 categories — engineering, marketing, finance, legal, HR, design, data science, and more.

Every role comes with:

A full system prompt (the "act as..." part, done properly)
6-10 structured prompt templates with input/output schemas
Eval rubrics for scoring the AI's output
Model routing hints (reasoning vs. balanced vs. fast)

No API key. No signup. No rate limits on Layer 1. CORS enabled. Just fetch JSON.

Quick example

# Get all 185 roles
curl https://godle.app/api/v3/roles.json

# Get the Software Engineering role with all templates
curl https://godle.app/api/v3/roles/software-engineering.json

# Get all 24 categories
curl https://godle.app/api/v3/categories.json

Each role JSON includes everything you need:

{
  "id": "software-engineering",
  "label": "Software Engineering",
  "systemPrompt": "# Role Identity\nYou are an expert Software Engineering professional...",
  "templates": [
    {
      "key": "system_design",
      "label": "System Design",
      "promptTemplate": "Design a system for {{input}}...",
      "example": "Design a real-time notification system for 10M users...",
      "inputSchema": { ... },
      "outputSchema": { ... },
      "modelHint": "reasoning"
    }
  ],
  "evalRubric": { ... }
}

Why static JSON?

I wanted something that:

Works offline (cache the JSON, you're done)
Has zero vendor lock-in (it's just files on a CDN)
Can be consumed by any language, any framework, any AI agent
Costs nothing to run at scale

The entire API is pre-generated static JSON served from Vercel's CDN. No server, no database, no cold starts.

MCP support

This is the part I'm most excited about. GODLE exposes 4 MCP tools that any MCP-compatible AI agent can discover and call:

godle_list_roles      — Find roles by category or keyword
godle_match_capability — Match a task description to the best role/template
godle_execute_task     — Run a template with structured inputs
godle_compose_workflow — Execute multi-step DAG workflows

MCP manifest: https://godle.app/.well-known/mcp.json

There's also an A2A (Agent-to-Agent) agent card at https://godle.app/.well-known/agent.json for Google's agent protocol.

JavaScript SDK

If you want a nicer interface than raw fetch calls:

<script src="https://godle.app/api/v3/godle-sdk.js"></script>
<script>
  const roles = await GODLE.listRoles();
  const prompt = await GODLE.generatePrompt('data-science', 'exploratory_data_analysis', {
    input: 'Analyze customer churn in our SaaS product'
  });
</script>

The SDK is 128KB, zero dependencies, works in browser and Node.js. It includes MCP client/server, A2A client/server, workflow execution, sessions, and streaming.

Source on GitHub: github.com/VC-code-project/godle-sdk

What's in the 185 roles

Here's a sample across categories:

Category	Example roles
Engineering	Software Engineering, Frontend, DevOps, ML Engineering, Data Engineering
Product & Design	Product Management, UX Design, UI Design, Product Ops
Marketing	Content Marketing, Growth, SEO, Social Media, Brand
Sales	Enterprise Sales, SDR/BDR, Account Management
Finance	FP&A, Accounting, Treasury, Tax, Audit
HR	Recruiting, L&D, Compensation, People Analytics
Legal	Corporate Law, Compliance, Contract Management, Privacy
Data	Data Science, Business Intelligence, Research Science

Full list: godle.app/jobs

Workflows and team packs

Beyond individual roles, the API includes:

12 workflows — multi-step DAG pipelines like feature-development (PRD → design → code → review), incident-response, content-campaign, hiring-pipeline

8 team packs — pre-configured agent teams like product-trio (PM + Designer + Engineer), saas-mvp (6 roles), data-team, enterprise-sales-team

All the endpoints

GET /api/v3/roles.json              # 185 roles
GET /api/v3/roles/{slug}.json       # Full role + templates
GET /api/v3/categories.json         # 24 categories
GET /api/v3/workflows.json          # 12 workflows
GET /api/v3/workflows/{id}.json     # Full workflow
GET /api/v3/evals.json              # 1,741 eval rubrics
GET /api/v3/team-packs.json         # 8 team packs
GET /api/v3/team-packs/{id}.json    # Full team pack
GET /api/v3/capabilities.json       # Searchable index
GET /api/v3/index.json              # API manifest