/lmarena/arenas

POST /api/lmarena/arenas

Price: 1 credit

List the LMArena arenas and the categories each one ranks

How to use it

Call this first when you do not know which arena answers a question: it returns each arena's own category list, which is what /lmarena/leaderboards accepts, plus how many models and votes the board holds. `has_pricing` tells you whether entries in that arena will carry prices at all. Arenas are returned in alphabetical order, so a low `count` is a prefix, not a ranking. The `agent` arena ranks by tool-use signal scores instead of blind-vote Elo, so it is listed here but /lmarena/leaderboards does not serve it.

Parameters

• access-token string required

Request body

• timeout integer — Max scrapping execution timeout (in seconds) (default: 300; min: 20; max: 1500)
• count integer required — Max result count (min: 1)

Response

• @type string (default: "LmarenaArenaSummary")
• alias string required
• url string required
• name string nullable
• description string nullable
• nav_description string nullable
• categories array (default: [])
• groups array (default: [])
• has_style_control boolean nullable
• has_pricing boolean nullable
• has_score_filter boolean nullable
• is_symmetric_ci boolean nullable
• is_shown_in_nav boolean nullable
• total_model_count integer nullable
• total_vote_count integer nullable
• vote_cutoff_at string nullable

Errors

• 422 — The request body did not validate Check the fields against this schema. A URN with the wrong prefix is the most common cause.
• 408 — The request ran past its time limit Raise `timeout` in the request body, up to the maximum this endpoint documents. Lowering `count` or turning off the `with_*` flags also helps, because less work finishes sooner.
• 412 — The entity was not found, or a precondition failed Retrying will not help: either the entity does not exist, or the input points at a different one.
• 429 — Too many requests: a rate limit or a usage window is exhausted When the response carries an X-Retry-After header, wait that many seconds and retry: the same number is in the body as `detail.retry_after`, and the limit clears once that window passes. The message in the body names the limit that was hit.
• 500 — Something broke on our side Retrying will not help. If it keeps happening, send us the X-Request-ID from the response headers.
• 529 — Rate limit reached, or the endpoint is overloaded Wait at least 30 seconds, then retry.

Response headers

• X-Error — Error message text (present only on error)
• X-Request-ID — Unique request identifier
• X-Execution-Time — Execution time in seconds
• X-Result-Count — How many records the body carries. 0 means an empty result, which is a normal answer and not by itself an error. A non-zero count can come back together with X-Error when the failure happened partway through — read this header and X-Error independently.
• X-Total-Available-Results — How many records exist for this query, when the endpoint can say. On a `dry_run` request this is the answer and the body is empty. It saturates: the endpoint's documented maximum means 'at least that many', any smaller number is exact.
• X-Warning — Present when the request body carried keys this endpoint does not document. They were ignored, so any filter you meant to apply through them did not apply. Check the spelling against this schema and retry.
• X-Retry-After — Seconds to wait before retrying. Present only on 429.