API + MCP

Open JSON over HTTPS, and a live MCP server for agents. ~3,860 events / ~39,200 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 (price_as_of on every market). Catalyst dates (CPI, FOMC, jobs, earnings) are joined per event. Read-only.

Machine-readable spec: api.clearmarket.fyi/openapi.json (OpenAPI 3.1) — the complete endpoint inventory for codegen and agents.

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=

limit caps at 100 per page — page through with 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'

GET/v1/marks?since=&status=&platform=&limit=&cursor=

Bulk and incremental pull. Without since: the whole universe, 1,000 per page via next_cursor. With since (the as_of of your last pull): only markets whose price, volume or status changed after it. Every row carries two clocks: price_as_of (last price change) and last_checked_at (last seen in a live venue feed; null means not seen since the last reload, so treat the price as historical).

curl -s 'https://api.clearmarket.fyi/v1/marks?since=2026-09-17T13:00:00Z' | jq '.count, .marks[0]'

GET/v1/status

Feed integrity. One object with an overall state (ok, degraded, stale) and a per-pipeline check for prices, daily history, status reconcile, sweep apply and the eligibility screen, each with as_of, age and threshold. Poll it before trusting a pull.

GET/v1/markets/movers

Largest day-over-day price moves on volume, across the open universe.

GET/v1/signals · /v1/signals/{slug}

The CM Signal wire: cross-venue divergence, benchmark drift, news-cycle and volume-spike bulletins.

GET/v1/spot

Reference spot prices (crypto) used by benchmark-drift signals.

Eligibility screens ship as site artifacts, not /v1 routes: HTML · JSON · CSV — join to the API on cm_market_id = market_id. Index at /screens/.

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

Connect your agent

One step on most platforms — the server is open, read-only, no auth, so there is nothing to configure beyond the URL.

Claude Code

claude mcp add clearmarket --transport http https://api.clearmarket.fyi/mcp

Claude Desktop

Settings → Connectors → Add custom connector, then paste https://api.clearmarket.fyi/mcp.

ChatGPT

Turn on Developer Mode, then Settings → Apps → Create app and paste https://api.clearmarket.fyi/mcp.

Codex CLI

codex mcp add clearmarket --url https://api.clearmarket.fyi/mcp

Cursor

Add to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "clearmarket": { "url": "https://api.clearmarket.fyi/mcp" }
  }
}

Grok

In a chat: + → Add connector → Custom, then paste https://api.clearmarket.fyi/mcp.

Other platforms / stdio-only clients

Any MCP client that takes a remote URL works with https://api.clearmarket.fyi/mcp directly. Clients that only speak stdio can bridge 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