Quickstart

The public Index API base URL is https://api.cambent.ai. No key for /v1/index/tkx, /v1/models, /v1/tasks, /v1/events, or /openapi.json. Only paid history and higher limits need a key.

1. Get the current index

curl -sS "https://api.cambent.ai/v1/index/tkx"

Example of the response shape. The values in the page source are placeholders, not a reading. When the keyless call succeeds, this block shows the live JSON.

{
  "source": "Cambent TKX",
  "asOf": "YYYY-MM-DD",
  "scoringVersion": "placeholder",
  "constructionVersion": "placeholder",
  "methodology": "https://cambent.ai/methodology",
  "series": {
    "tkx": {
      "id": "tkx",
      "name": "TKX",
      "value": null,
      "asOf": "YYYY-MM-DD"
    },
    "tkx-open": {
      "id": "tkx-open",
      "name": "TKX-Open",
      "value": null,
      "asOf": "YYYY-MM-DD"
    },
    "tkx-frontier": {
      "id": "tkx-frontier",
      "name": "TKX-Frontier",
      "value": null,
      "asOf": "YYYY-MM-DD"
    }
  },
  "freshness": {
    "state": "placeholder",
    "lagging": null,
    "asOf": "YYYY-MM-DD",
    "requiredAsOf": "YYYY-MM-DD",
    "rule": "placeholder"
  },
  "marketHigh": null,
  "marketLow": null
}

Field	Meaning
source	Attribution string
asOf	Date of the reading. The same date sits on each series.
series.tkx / series.tkx-open / series.tkx-frontier	Index level against the Aug 4, 2026 baseline (100), with that series' asOf
freshness	When the data may be behind (the last update is older than the previous weekday's close), state is STALE and lagging is true. The index level stays the same.
scoringVersion / constructionVersion	Cite using the methodology page
methodology	Human methodology URL
marketHigh / marketLow	Market extremes on the panel

2. History

Anonymous history is the last 30 days. Scope read-index unlocks the fuller dated archive.

curl -sS "https://api.cambent.ai/v1/index/tkx/history?from=YYYY-MM-DD&to=YYYY-MM-DD&interval=day"

curl -sS "https://api.cambent.ai/v1/index/tkx/history?from=YYYY-MM-DD&to=YYYY-MM-DD&interval=day" \
  -H "Authorization: Bearer YOUR_API_KEY"
# or: -H "X-Api-Key: YOUR_API_KEY"

Send the key as Authorization: Bearer or X-Api-Key. Keys are issued when you Request Access. There is no public form that mints keys for strangers.

3. Look up a model

curl -sS "https://api.cambent.ai/v1/models/{id}"

Primary fields: input_price, output_price, quality_by_task, quality_source, price_source, grounding_tier, asOf.

Live series ids: tkx, tkx-open, tkx-frontier.

Other public GETs

No key: /v1/index, /v1/models, /v1/methodology, /v1/tasks, /v1/events, /health, and OpenAPI at /openapi.json.

Rate limits and errors

Anonymous Index: 120 requests per minute per IP (X-RateLimit-Limit, X-RateLimit-Scope: anonymous). Keyed calls use the issued plan rate.

Error envelope: source, error, message (plus scope / limit / retryAfter when relevant).

{
  "source": "Cambent TKX",
  "error": "not_found",
  "message": "Unknown index id. Live series: tkx, tkx-open, tkx-frontier."
}

Cite the TKX: Source: Cambent TKX (https://tkx.cambent.ai), as of the response asOf. Methodology: https://cambent.ai/methodology.

Cambent publishes the signal; you decide.

API Docs