🚀Building CryptoMate — An AI Agent for Real‑Time Crypto Insights on Telex.im

Udoh Gary — Mon, 03 Nov 2025 17:02:05 +0000

The Challenge

Keeping up with cryptocurrency prices, historical highs/lows, and significant events like halving is time‑consuming and error‑prone. I wanted to build an agent that could:

Fetch live pricing for any coin
Answer questions like “When was the all‑time high for SHIB?” or “When is the next BTC halving?”
Integrate seamlessly into Telex.im so users can chat in a familiar workspace

This is the story of how I built CryptoMate, using the Mastra agent framework and integrated it via Telex’s A2A protocol.

🧪 Tech Stack

Here’s what I used:

Mastra: for defining the agent and workflows
Telex.im: for chat‑agent integration via JSON‑RPC A2A
Node.js + Express: backend server for the agent
Axios: to fetch data from the CoinGecko API
Railway.app: cloud hosting and deployment

⚙️ Architecture Overview

🧑‍💻 User message (via Telex)
        ↓
📡 JSON-RPC Request
        ↓
🧠 Express Server (Node.js)
        ↓
⚙️ Logic Layer 
      ├─ CoinGecko API (for live crypto data)
      └─ Mastra Agent (for natural-language handling)
        ↓
💬 JSON-RPC Response
        ↓
📱 Message displayed on Telex

🧠 Building CryptoMate with Mastra

Step 1. Install Mastra

In the project folder, run:

npm install @mastra/core

This installed the core Mastra package which includes agent, tools, workflows and more. ([npmjs.com][1])

Step 2: Agent setup

import { Agent } from "@mastra/core/agent";
import dotenv from "dotenv";
dotenv.config();

export const cryptoTrackerBot = new Agent({
  name: "crypto-tracker-bot",
  instructions: `
    You are a helpful cryptocurrency assistant.
    You can answer general crypto-related questions,
    provide insights about Bitcoin, Ethereum, and other coins,
    and guide users about the crypto market.
    If the user asks for a price, the data will be fetched from an API,
    so just confirm it politely.
    Keep your responses short, clear, and friendly.
  `,
  model: "gpt-4o-mini",
  openaiApiKey: process.env.OPENAI_API_KEY
});

Step 3: I Used the agent in theserver/backend

In server.js, when you receive a message from Telex, call:

const aiResponse = await cryptoTrackerBot.run(text);

This sends the user’s input to Mastra, gets a response, and you can then send that reply back to Telex in the correct JSON-RPC format.

Step 4: I created the Mastra workflow.json file

This file communicates with Telex the location and function of the Ai agent

{
  "active": true,
  "category": "utilities",
  "description": "A crypto tracker bot that provides real-time prices for cryptocurrencies.",
  "id": "cryptoTrackerBot123",
  "long_description": "You are a helpful crypto tracker bot that fetches live cryptocurrency prices and market information using the CoinGecko API. Users can ask for the price of any coin by name or symbol.",
  "name": "crypto-tracker-bot",
  "nodes": [
    {
      "id": "crypto_tracker_bot_node",
      "name": "crypto-tracker-bot",
      "parameters": {},
      "position": [500, 100],
      "type": "a2a/mastra-a2a-node",
      "typeVersion": 1,
      "url": "cryptomate-production.up.railway.app"
    }
  ],
  "pinData": {},
  "settings": {
    "executionOrder": "v1"
  },
  "short_description": "Tracks live crypto prices using CoinGecko"
}

🔗 Deploying & Telex Integration

Deployed to Railway.app and updated the workflow.json with the live URL
Added the agent on Telex.im and published it 🔗 Link to my agent: [https://telex.im/telex-ai-intergration/colleagues/019a4767-aadf-7e17-99e9-954eaa1d3545/019a4767-1277-7d2d-8e9e-714192aff16e] (What the agent does: provides live crypto pricing and insights, handles coin history and concept questions.)

And of course: https://telex.im/ — an AI agent platform like Make, a Slack alternative for bootcamps and communities.

🧠 What Worked & What Didn’t

✅ Worked

Mastra made creating the agent straightforward
Telex A2A protocol integration was smooth once the JSON format was correct
CoinGecko provided reliable price data

❌ Challenges

Initial Mastra install issue: had to install via GitHub because npm install mastra failed
Workflow trigger sometimes showed “Will the workflow run: False” — resolved by re‑uploading the updated workflow.json and ensuring the URL matched deployment
Handling non‑price questions gracefully required adding the timeout logic so Mastra fallback didn’t hang

📌 Tips for Your Own Agent

Start simple: price queries first, fallback logic later
Test locally with Postman or curl before Telex
Use environment variables — never hardcode API keys
Monitor logs: what Telex sends vs what your endpoint receives
Re‑upload your workflow every time you change the URL

💡 The project is open to the community!

Feel free to:

Check out the source code
Open issues or share feedback
Contribute enhancements
Fork it and build your own version

👉 https://github.com/GodlyPatrick/CryptoMate.git

🎉 Conclusion

Building CryptoMate showed me just how powerful the combination of Mastra + Telex can be for agents. Whether you’re tracking prices, building a dev‑assistant, or automating community workflows, this stack gives you a fast path from idea → live chatbot.
Go ahead and build something cool!

DEV Community: Udoh Gary