Crypto Sentiment X402 MCP server

Crypto Sentiment API (x402)

Pay-per-call crypto sentiment API for AI agents. No API keys, no subscriptions — agents discover it, get an HTTP 402, pay in USDC on Base, and get the data.

Sentiment sources (all free, no keys required):

Magazine, The Block, CryptoSlate, NewsBTC, CryptoPotato

• Crypto news RSS (8 outlets) — CoinDesk, Cointelegraph, Decrypt, Bitcoin

• Fear & Greed Index — alternative.me

Scoring: VADER sentiment analysis, extended with a crypto slang lexicon (moon, rekt, rug, hodl, bullish/bearish, etc.) so slang isn't scored as neutral.

1. Get a Base wallet address

You need an address to receive USDC payments. Any standard Ethereum-style wallet works on Base (e.g. Coinbase Wallet, MetaMask configured for Base). You do not need to give this app your private key — only the public address, to receive funds.

2. Run it locally (testnet — free, no real money)

cd crypto-sentiment-x402
cp .env.example .env
# edit .env and set PAY_TO_ADDRESS to your wallet address
pip install -r requirements.txt
uvicorn app.main:app --reload

Visit http://localhost:8000 — you'll see the API description. Calling http://localhost:8000/sentiment/BTC without payment returns an HTTP 402 with payment instructions, exactly what an agent's x402 client would see and act on automatically.

To actually test a paid call, use the official x402 test client (needs Base Sepolia testnet USDC — free from the Base Sepolia faucet):

pip install x402
python -m x402.examples.client --url http://localhost:8000/sentiment/BTC

3. Deploy (simplest path: Render.com)

Render will read render.yaml automatically.

1. Push this folder to a new GitHub repo.
2. Go to render.com → New → Blueprint → connect the repo.

wallet address.

1. When prompted, set the PAYTOADDRESS environment variable to your

URL like https://crypto-sentiment-x402.onrender.com.

1. Deploy. Render builds the Dockerfile and gives you a public HTTPS

That's it — testnet mode is on by default, so nothing costs real money until you flip X402_NETWORK to mainnet (step 4 below).

4. Go live with real USDC payments

account and create an API key — this is required for the mainnet facilitator (production-grade payment verification/settlement).

1. Sign up for a free Coinbase Developer Platform

1. In Render, set:

not a testnet-only address)

• X402_NETWORK=mainnet
• CDPAPIKEY_ID=...
• CDPAPIKEY_SECRET=...
• PAYTOADDRESS = your mainnet Base address (double-check it's

1. Redeploy. Calls now settle real USDC on Base mainnet.

Start with a low price (X402PRICEUSD, default $0.01) while you validate everything works end-to-end.

5. List it so AI agents can find and pay you

This is the x402 Bazaar — Coinbase's discovery layer, essentially a search engine for agents looking for x402 services.

4), your service becomes automatically discoverable in the Bazaar once you process your first real payment through it — no separate signup.

• If you're using the CDP facilitator (i.e. you're on mainnet per step

description field in app/main.py's RouteConfig clear and specific (already set) — that text is what shows up in Bazaar search results.

• To improve how well agents can find and understand it, keep the

https://api.cdp.coinbase.com/platform/v2/x402/discovery/resources (public, no key needed) to confirm your service appears after going live.

• You can browse the current Bazaar listing yourself at

x402bazaar.org, a community-run directory of x402 services, separate from Coinbase's own Bazaar.

• Optional extra distribution: submit your API to

MCP server (Claude Desktop / Claude Code)

Shortened. The full README is on GitHub.