API + MCP

Open JSON over HTTPS, and a live MCP server for agents. ~2,450 events / ~20,000 markets across Kalshi and Polymarket, each with a Resolution Clarity Grade — the named resolution source where one is committed, and a graded source_status when it isn't. No key required.

Every event is single-venue; the same question priced on both venues is linked by a shared question_id, and each market's also_on lists its cross-venue twins. Prices refresh hourly. Catalyst dates (CPI, FOMC, jobs, earnings) are joined per event. Read-only.

ACCESS

Open by default. Full universe, no key, 1,000 requests/day per IP. Drop your email for a free key and 10,000/day — issued instantly, no confirmation step:

Prefer the API? Request a key with curl

curl -s -X POST https://api.clearmarket.fyi/v1/keys \
  -H 'content-type: application/json' \
  -d '{"email":"[email protected]"}'

Anonymous access works too — just omit the key. CORS open.

REST · THE WORKBENCH

Query and filter the universe directly. Every response is the canonical schema with derived fields added at serve time.

GET/v1/events?category=&platform=&grade=&q=&limit=&offset=

curl -s 'https://api.clearmarket.fyi/v1/events?category=economics&grade=A&limit=5' \
  | jq '.events[] | {slug, grade, question}'

GET/v1/events/{slug}?detail=concise

Full event: linked markets, grades, windowed catalysts. ?detail=concise trims each market to the essentials (grade, price, source) for large multi-market events.

curl -s https://api.clearmarket.fyi/v1/events/kxgdpyear-26 \
  | jq '{question, catalyst_dates, markets: (.markets | length)}'

GET/v1/markets/{market_id}

Single market: price, Resolution Clarity Grade, resolution provenance.

GET/v1/catalysts/upcoming?days=N

Scheduled catalysts across all events, cross-event view.

curl -s 'https://api.clearmarket.fyi/v1/catalysts/upcoming?days=14' | jq '.catalysts'

MCP · THE HANDSHAKE

The agent-first surface. Same data, spoken as tools an agent calls directly. No HTML to crawl, no REST to compose. Streamable HTTP at https://api.clearmarket.fyi/mcp. Open, read-only.

Note: the endpoint is the path /mcp on the API domain — api.clearmarket.fyi/mcp, not an mcp. subdomain. POST JSON-RPC (application/json is enough; text/event-stream is only needed if you consume the SSE stream).

tools

list_eventsbrowse / search the universe (set q)

get_eventfull graded record for one event. detail=concise trims each market to grade + price + source (much smaller for many-market events)

get_marketprice + resolution provenance. Accepts a ClearMarket id (CM-MKT-…), a venue-native id / Kalshi ticker, or a market URL (best-effort — Kalshi URLs resolve; Polymarket needs the conditionId) — returns the canonical CM-MKT-… id

list_upcoming_catalystsscheduled catalysts, next N days

list_signalsbrowse the CM Signal wire (filter by event, category, venue, type)

get_signalfull wire bulletin by slug

Claude Desktop / Cursor

Add to claude_desktop_config.json or ~/.cursor/mcp.json (bridges stdio to the remote server via mcp-remote):

{
  "mcpServers": {
    "clearmarket": {
      "command": "npx",
      "args": ["-y", "mcp-remote", "https://api.clearmarket.fyi/mcp"]
    }
  }
}

Verify (raw JSON-RPC)

curl -s -X POST https://api.clearmarket.fyi/mcp -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}' \
  | jq '.result.tools[].name'

AGENT · THE MANIFEST

A plain-text surface engineered for LLM context windows. Zero markup, token-optimized, enumerates every endpoint and tool.

/llms.txt [density: high] [context: token-optimized]

SCHEMA

JSON Schema (draft 2020-12). API responses are the schema with derived fields added at serve time.

Repository: github.com/JDSource/clearmarket