---
title: "Creates a run that evaluates an explicit list of matchup configurations, each with its own response count."
method: POST
path: "/leaderboard/{leaderboardId}/runs/custom"
tags: ["Leaderboard"]
---

# Creates a run that evaluates an explicit list of matchup configurations, each with its own response count.

`POST /leaderboard/{leaderboardId}/runs/custom`

## Request

- Base URL: `https://api.rapidata.ai`
- URL: `https://api.rapidata.ai/leaderboard/{leaderboardId}/runs/custom`
- Auth: OpenID Connect (`https://auth.rapidata.ai/.well-known/openid-configuration`, scopes: `openid`, `profile`, `email`, `offline_access`, `api`)

Answers 202 once the configurations are validated and the run is queued; it then starts
 behind whatever else is queued on the leaderboard, and its matchups are resolved at that
 point. Poll GET /leaderboard/{leaderboardId}/runs for its status. Every id is
 verified before the 202, but a configuration that resolves to no matchups is only found at
 start and is skipped; the run fails when all of them do. At most 2000 configurations,
 1000000 responses and 10000 referenced ids per request.

## Path parameters

- `leaderboardId` string, required

## Request body

- CreateCustomRunEndpointInput
  - `name` string, required: The display name of the run.
  - `matchups` MatchupConfig[], required: The matchup configurations to evaluate, 1 to 2000 of them.
    - `participantIds` string[], nullable
    - `tags` string[], nullable
    - `promptIdentifiers` string[], nullable
    - `sampleIds` string[], nullable
    - `responses` integer, required
  - `seed` integer, nullable: Optional seed for deterministic matchup selection. Reuse it across a benchmark's leaderboards to align them on the same image pairs; omit for random selection.

## Response `202`

Accepted

- CreateCustomRunEndpointOutput
  - `runId` string, required: The id of the queued run.

## Other responses

- `400`: Bad Request
- `401`: Unauthenticated
- `403`: Forbidden

## Changes

- **2026-09-04** `9da534659e5f`: 1 info
  - the security scope `api` was added to the endpoint's security scheme `OpenIdConnect`
- **2026-08-27** `4ee3e6f5e4f4`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/rapidata/apis/rapidata-api/changes/leaderboard/:leaderboardId/runs/custom/post.md)

---

[API](https://skmtc.dev/rapidata/apis/rapidata-api.md) - [All operations](https://skmtc.dev/rapidata/apis/rapidata-api/llms.txt) - [OpenAPI document](https://skmtc.dev/rapidata/apis/rapidata-api/revisions/004a977d7d9f?raw)