CF Benchmarks REST Passthrough

Overview

The CF Benchmarks REST passthrough lets you query the CF Benchmarks REST API using your existing Kalshi API credentials. Requests are authenticated the same way as any other Kalshi Trade API call, so you do not need a separate CF Benchmarks API key. Send a request to the /cfbenchmarks endpoint and the path and supported query parameters are forwarded to CF Benchmarks. The upstream response is returned wrapped in a standard Kalshi data envelope. The passthrough ignores includeVerification, regardless of its value, to avoid upstream verification timeouts. Optional on-chain verification data is not available through this endpoint. Other parameters, including id and maxResolution, are forwarded unchanged.

Access

The passthrough requires an authenticated Kalshi Trade API request, and it is available only to accounts with the appropriate entitlement. If you receive an authorization error and believe you should have access, contact Kalshi.

Rate limit

Each passthrough request costs 50 tokens from your Read bucket; the default request costs 10. At the Basic tier’s 200 tokens-per-second read budget, that sustains 4 requests per second. See Rate Limits and Tiers for budgets and bucket behavior.

Base URL and Path Mapping

Use the production Trade API base URL (see API Environments for all hosts and the demo environment):

https://external-api.kalshi.com/trade-api/v2

Everything after /cfbenchmarks/, including query parameters other than includeVerification, is forwarded to the CF Benchmarks REST API at https://www.cfbenchmarks.com/api/v1/.

Kalshi request	Forwarded to
`GET /trade-api/v2/cfbenchmarks/values?id=BRTI`	`https://www.cfbenchmarks.com/api/v1/values?id=BRTI`

Authentication

Authenticate with standard Kalshi API key request signing. See API Keys and Quick Start: Authenticated Requests for the full signing flow. As with all Trade API endpoints, sign the request path from the API root without the query string:

/trade-api/v2/cfbenchmarks/values

Example

curl "https://external-api.kalshi.com/trade-api/v2/cfbenchmarks/values?id=BRTI" \
  -H "KALSHI-ACCESS-KEY: <your-access-key>" \
  -H "KALSHI-ACCESS-SIGNATURE: <request-signature>" \
  -H "KALSHI-ACCESS-TIMESTAMP: <timestamp-ms>"

The raw CF Benchmarks payload is returned under the data field:

{
  "data": {
    "serverTime": "2019-08-13T23:30:53.992Z",
    "payload": {}
  }
}

Historical Values

Historical index values are available through the same passthrough via the CF Benchmarks history endpoint. For example, to retrieve one hour of BRTI values:

curl "https://external-api.kalshi.com/trade-api/v2/cfbenchmarks/history/values?id=BRTI&timespan=HOUR&timestamp=2026-08-21T14:00:00.000Z" \
  -H "KALSHI-ACCESS-KEY: <your-access-key>" \
  -H "KALSHI-ACCESS-SIGNATURE: <request-signature>" \
  -H "KALSHI-ACCESS-TIMESTAMP: <timestamp-ms>"

This forwards to https://www.cfbenchmarks.com/api/v1/history/values with the same query parameters, except for includeVerification. As with all passthrough requests, sign the path without the query string:

/trade-api/v2/cfbenchmarks/history/values

The history endpoint returns tick-level values, and some indices publish at intra-second granularity there, so a single window can contain a large number of points. For the supported indices, parameters, and granularities, refer to the official CF Benchmarks API documentation.

Available Endpoints

The passthrough forwards any path and query parameters supported by CF Benchmarks, except for includeVerification. For the list of available endpoints, supported parameters, and index identifiers (such as BRTI), refer to the official CF Benchmarks API documentation.

Error Handling

The passthrough maps upstream conditions to standard Kalshi error responses:

Condition	Kalshi response
Resource not found upstream	`404 not_found`
Upstream rate limit exceeded	`429 too_many_requests`
Upstream authorization failure, server error, or timeout	`503 service_unavailable`
Other upstream client errors	`400 bad_request` (with upstream detail)

REST