crypto-pulse-api (Solana x402)

Pay-per-request crypto market pulse for AI agents. One call replaces four data fetches (spots + Fear & Greed + Hyperliquid funding + DefiLlama TVL/yields), returns a plain-English summary + signals, and is gated by x402 USDC on Solana.

Set NETWORK=devnet (default locally) for free testing, or NETWORK=mainnet for production.

Live: https://cryptopulseapi.com (legacy alias still up: https://137-184-201-7.sslip.io) — source: https://github.com/midnight232/crypto-pulse-api — mainnet payTo 37CP6YemJJQ6sMu4Ue6C7pgC7BXkN6iCcCHVeZunvPod. Facilitator: Coinbase CDP (PayAI listing retained). See DEPLOY.md.

What it returns

GET /v1/pulse (paid, $0.02 USDC) returns compact JSON:

• BTC / ETH / SOL / HYPE spot USD (CoinGecko, no API key)

• Crypto Fear & Greed (alternative.me)

• Hyperliquid perpetual funding for BTC / ETH / SOL / HYPE

• DefiLlama total TVL + a few high-TVL stablecoin yields

• summary: one plain-English line derived from those fields

• signals: deterministic sentiment + funding bias flags

Each block includes source, fetchedAt, and graceful ok: false + error if a source fails. Live responses are cached in-memory for 60 seconds.

Also:

• GET /v1/pulse/:asset — single ticker (BTC|ETH|SOL|HYPE), $0.02

• GET /v1/spots — spots only + summary, $0.005

• GET /v1/sample — free same shape as full pulse, may be up to 15 minutes old (10 req/min/IP)

• POST /mcp — Streamable HTTP MCP (get_market_sample free; paid tools return x402 payment requirements + HTTP URLs)

Free discovery: GET /, GET /health, GET /llms.txt, GET /.well-known/x402, GET /openapi.json.

Related MCP server: cerebrus-pulse-mcp

Why agents use this

Typical single-purpose Solana x402 market tools list around $0.001–$0.005 each (spots-only, Fear & Greed-only, funding-ish, DeFi-only). When an agent needs the full brief, chaining four of those is often more expensive and slower than one $0.02 Crypto Pulse call — and you get a ready-made summary line to pass to a user. See competitor table in MARKETING.md.

How payment works

1. Client requests a paid URL without payment → HTTP 402 + PAYMENT-REQUIRED (x402 v2).

2. Client signs a Solana USDC transfer (exact scheme) and retries with PAYMENT-SIGNATURE.

3. Server asks the configured facilitator (CDP on mainnet live; x402.org on devnet) to verify + settle.

4. On success → HTTP 200 + JSON (+ PAYMENT-RESPONSE).

Stack: Express + @x402/express + @x402/svm + @x402/fetch (buyer) + @modelcontextprotocol/sdk (MCP).

Setup (devnet)

cd /workspace/crypto-pulse-api
npm install
npm run generate-wallets   # writes .devnet-keys/{seller,buyer}.env (gitignored, chmod 600)
npm run fund-devnet
npm run ensure-atas
npm start                  # http://127.0.0.1:4021

npm run smoke
npm run test:summary
# Against a running server:
PUBLIC_BASE_URL=http://127.0.0.1:4021 npm run test:mcp
npm run buy                # full paid flow (needs buyer DEVNET USDC)

Never commit .devnet-keys/, .mainnet-keys/, .cdp-keys/, .do-token, or .deploy-ssh/. Never print secret keys.

MCP

Remote (live): https://cryptopulseapi.com/mcp

Local stdio:

PUBLIC_BASE_URL=https://cryptopulseapi.com npm run mcp:stdio

Official MCP Registry: io.github.midnight232/crypto-pulse (mcp/server.json). Smithery draft not published. See MARKETING.md.

Project layout

src/server.js          Express + x402 + sample + MCP mount
src/pulse.js           Public data aggregation + caches
src/summary.js         Plain-English summary + signals
src/discovery.js       llms.txt / well-known / OpenAPI
src/mcp-server.js      Streamable HTTP MCP tools
src/config.js          NETWORK / facilitator / payTo
mcp/stdio.js           Local stdio MCP proxy
mcp/server.json        Official MCP Registry draft
mcp/smithery.yaml      Smithery draft
scripts/…              wallets, buy, smoke, tests

Mainnet / deploy

See DEPLOY.md. Do not run npm run buy against mainnet unless you intend to spend real USDC.

License

MIT