---
title: "Promote a compose candidate to the active composition"
method: POST
path: "/v1/projects/{id}/compose/jobs/{composeJobId}/select"
tags: ["compose"]
---

# Promote a compose candidate to the active composition

`POST /v1/projects/{id}/compose/jobs/{composeJobId}/select`

## Request

- Base URL: `https://api.cueframe.ai`
- URL: `https://api.cueframe.ai/v1/projects/{id}/compose/jobs/{composeJobId}/select`
- Auth: one of:
  - HTTP bearer
  - OAuth 2 (authorization code, authorization URL `https://api.cueframe.ai/api/auth/mcp/authorize`, token URL `https://api.cueframe.ai/api/auth/mcp/token`, scopes: `projects:write`)
  - API key in header `PAYMENT-SIGNATURE`

Selects one candidate from a finished compose ensemble and writes it to the project's composition. `selectStrategy` decides how the editor draft interacts with the write (per compose-api-contract.md).

## Path parameters

- `id` string, required
- `composeJobId` string, required

## Request body

- ComposeSelectRequest: POST /projects/:id/compose/jobs/:jobId/select body.
  - `candidateIndex` integer, required
  - `selectStrategy` 'agent-authoritative' | 'editor-merge' | 'editor-replace', required
  - `ifMatch` string

## Response `200`

Candidate selected; etag returned for adoption.

- ComposeSelectResponse: POST /projects/:id/compose/jobs/:jobId/select response.
  - `newCompositionEtag` string, required
  - `mergeResult` object
    - `replayedEdits` integer, required
    - `droppedEdits` object[], required
      - `trackId` string, required
      - `clipId` string
      - `wordStartMs` number
      - `reason` 'target_removed' | 'conflict', required

## Other responses

- `400`: Bad request — validation_error / invalid_cursor / invalid_query.
- `401`: Missing or invalid Authorization header.
- `402`: Payment required. Returned when the caller presents no API key on a priced operation: the body AND the `Payment-Required` header carry the x402 v2 challenge (accepted scheme, network, USDC asset, amount, payTo). Sign the EIP-3009 authorization and retry with a `PAYMENT-SIGNATURE` header. A KEYED caller sees this status instead when their plan lacks or has exhausted the feature (`billing_required`).
- `403`: Forbidden — permission insufficient.
- `404`: Resource not found.
- `409`: Conflict — stale_etag / idempotency_conflict / suggestions_already_complete.
- `422`: Unprocessable — invalid_composition / media_in_use / session_in_use / render_not_cancellable.
- `429`: Rate limited. Retry-After header present.
- `500`: Internal error.

---

[API](https://skmtc.dev/cueframe/apis/cueframe-api.md) · [All operations](https://skmtc.dev/cueframe/apis/cueframe-api/llms.txt) · [OpenAPI document](https://skmtc.dev/cueframe/apis/cueframe-api/revisions/8f9bfe362b4a?raw)