Arbitron API and MCP server

Read-only market data for crypto perpetual futures across the venues Arbitron tracks: current funding rates, funding history, the spread between two venues right now, the scanner's backtested spreads, and the listings calendar. Two doors to the same data: a REST API for programs and an MCP server for AI assistants.

This repository holds the public artefacts of that product so they can be pinned, diffed and cited. The service itself is closed source.

What	Where
Developer guide	https://arbitron.app/developers (Markdown twin: https://arbitron.app/developers/index.md)
API reference (Scalar)	https://arbitron.app/developers/reference
OpenAPI 3.1 document	https://arbitron.app/api/v1/openapi.json (a copy: openapi/openapi.json)
MCP server	https://arbitron.app/mcp (Streamable HTTP; registry entry app.arbitron/mcp: mcp/server.json)
Server card	https://arbitron.app/.well-known/mcp/server-card.json
Plans and keys	https://arbitron.app/developers#plans, keys at https://arbitron.app/settings/api
llms.txt	https://arbitron.app/llms.txt

REST in one minute

export ARBITRON_KEY=arb_live_...   # https://arbitron.app/settings/api

# The most negative funding on liquid contracts
curl -s "https://arbitron.app/api/v1/funding?max_rate_pct=-0.01&min_volume_usdt=1000000&sort=rate_asc&limit=5" \
  -H "Authorization: Bearer $ARBITRON_KEY"

# The spread between venues right now, tradeable pairs only
curl -s "https://arbitron.app/api/v1/spreads?min_volume_usdt=500000&max_spread_pct=3&min_strength=2&fields=symbol,exchange_a,exchange_b,spread_pct,direction" \
  -H "Authorization: Bearer $ARBITRON_KEY"

Every response is { "data": ..., "meta": { "as_of", "delayed_seconds", "source", "url", "count", "total", "next_cursor" } }. Errors are RFC 9457 problem details. Rates are percent per settlement. More in examples/.

MCP in one minute

Claude Desktop, Cursor and ChatGPT connect with OAuth 2.1 (sign in with your Arbitron account); a program connects with the same API key as a bearer token. Client configurations are in mcp/clients/. Nine read-only tools: arbitron_search_coins, arbitron_get_funding_rates, arbitron_get_coin_funding, arbitron_get_funding_history, arbitron_get_spreads, arbitron_get_spread_backtest, arbitron_get_listings, arbitron_get_exchanges, arbitron_get_usage.

Plans

The Demo plan is free: 15-minute delayed data, 50 rows per page, no history. Paid plans (Developer, Pro, Business) are live, reach further back, and include commercial use. Details at https://arbitron.app/developers#plans.

Citing

Attribute republished figures as "Data: Arbitron" with a link to meta.url, and keep meta.as_of with the number. Name the exchange and the settlement interval beside any funding rate.

Contents of this repository

• openapi/openapi.json: the OpenAPI document as served, refreshed by scripts/refresh.sh.
• mcp/server.json: the manifest published to the official MCP registry.
• mcp/clients/: configuration snippets for Claude Desktop, Cursor and ChatGPT.
• examples/: curl, Python and Node examples.
• .cursor-plugin/: the plugin manifest for the Cursor marketplace.

Files here are licensed under the MIT License. The data the API returns is subject to the terms.