---
title: "Changes to Preview deterministic draft evaluators against stored evidence"
method: POST
path: "/projects/{projectId}/eval-runs/{runId}/backtest"
---

# Changes to Preview deterministic draft evaluators against stored evidence

`POST /projects/{projectId}/eval-runs/{runId}/backtest`

> Every recorded change to this endpoint, newest first.

## Timeline

Changed in 2 of 122 revisions.

- **2026-09-14** `56b9d1dda7ea` — 1 info
- **2026-09-14** `2349c6b8a3b8` — 1 info

## Changes

- **2026-09-14** `56b9d1dda7ea` — 1 info
  - added the new optional `header` request parameter `x-mcpjam-eval-vocabulary`
- **2026-09-14** `2349c6b8a3b8` — 1 info
  - endpoint added

---

[Operation](https://skmtc.dev/mcpjam/apis/mcpjam-api/docs/projects/:projectId/eval-runs/:runId/backtest/post.md) · [API](https://skmtc.dev/mcpjam/apis/mcpjam-api.md) · [Page](https://skmtc.dev/mcpjam/apis/mcpjam-api/changes/projects/:projectId/eval-runs/:runId/backtest/post)