---
title: "Preview a failed-cases rerun"
method: GET
path: "/projects/{projectId}/eval-runs/{runId}/rerun-preview"
tags: ["Eval runs"]
---

# Preview a failed-cases rerun

`GET /projects/{projectId}/eval-runs/{runId}/rerun-preview`

What `POST /projects/{projectId}/eval-runs/{runId}/rerun` with `scope: "failed_cases"` would execute, before anything spends. The platform selects every case with a trial that is not completed and passed; cancelled and skipped trials do not count. `reasons` and `excluded` count trials; `selectedCaseCount` counts cases. `rerunnable` is `false` while the run is still in flight (including `grading`) and when nothing qualifies.

## Path parameters

- `projectId` string, required
- `runId` string, required

## Response `200`

The rerun selection.

- object
  - `runId` string, required
  - `suiteId` string, required
  - `scope` 'failed_cases', required
  - `sourceStatus` string, required
  - `sourceTerminal` boolean, required — `false` while the source run is still executing or grading.
  - `totalCaseCount` integer, required
  - `selectedCaseCount` integer, required
  - `selectedCaseIds` string[], required
  - `reasons` object, required — Qualifying trials by the most specific reason: `failed`, `evaluator_error`, `timed_out`, `execution_failed`, `setup_failed`, `pending`.
  - `excluded` object, required — Trials that did not qualify: `passed`, `cancelled`, `skipped`.
  - `rerunnable` boolean, required — The source run finished and at least one case qualifies.

## Other responses

- `401` — Missing, invalid, revoked, or orphaned key (`UNAUTHORIZED`) — or the **target MCP server** needs an OAuth grant (`OAUTH_REQUIRED`), which is a property of the server, not your key.
- `403` — Key is valid but not allowed to do this.
- `404` — Unknown project, server, or resource.
- `429` — Per-key rate limit exceeded (60 requests/minute sustained, bursts up to 10). Honor `Retry-After` and back off with jitter.
- `500` — Something failed on MCPJam's side.

## Changes

- **2026-10-05** `aea5de5036d4` — 1 info
  - endpoint added

[Change history](https://skmtc.dev/mcpjam/apis/mcpjam-api/changes/projects/:projectId/eval-runs/:runId/rerun-preview/get.md)

---

[API](https://skmtc.dev/mcpjam/apis/mcpjam-api.md) · [All operations](https://skmtc.dev/mcpjam/apis/mcpjam-api/llms.txt) · [OpenAPI document](https://skmtc.dev/mcpjam/apis/mcpjam-api/revisions/97bd992b9977?raw)