Redline MCP Server

Run local prompt regression checks from prompt-response logs in AI coding assistants.

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What is the Redline MCP server?

Run local prompt regression checks from prompt-response logs in AI coding assistants. Exposed over MCP by the redline mcp server, that capability becomes something an assistant can invoke while it works, not something you go and do afterwards.

What it actually does

redline is an open-source, local-first eval tool for AI teams. It uses logs you already have: prompts, outputs, support tickets, traces, model responses, and production JSONL exports.

Its toolset

Everything the assistant can do here goes through one of these:

  • redline — command not found: run python -m pip install redline-ai, then
  • RedlineMiddleware — capture bounded JSON FastAPI or ASGI request/response pairs locally, with optional skip diagnostics
  • redline-mcp — let AI coding assistants run checks inside Claude, Codex,
  • uses — gowtham0992/redline@v0.3.0
  • self — contained HTML for side-by-side inspection, including feature and prompt eval tables
  • Proof — Command or data
  • Dashboard — HTML report
  • Signal — Example regression
  • Key — Purpose
  • suite — Suite baseline path, default redline-suite.json
  • max_cases — Maximum representative cases selected for a suite
  • replay — Command used by eval; prompts go to stdin by default. {prompt} is for small legacy argv runners; {prompt_file} passes a temporary rendered-prompt

Adding it to your client

Being a remote server, there is no local install. You register the endpoint with your client, authorise it once, and the tools appear.

When to reach for it

This sits in the monitoring and observability group, where several servers overlap in what they claim to do but differ sharply once you actually set them up. Redline's toolset — redline, RedlineMiddleware, redline-mcp and 11 more — is a fair guide to whether it matches your workflow. It is maintained by gowtham0992; worth a glance at recent repository activity before you build anything load-bearing on it.

We check each listing at SyncDev against the project's documentation before it goes live — if something here drifts out of date, it is a bug worth reporting.

Caveats

  • Your data travels to the provider's service, so the usual questions apply about what you send and what they retain.
  • With 14 tools registered it takes up a noticeable share of the context window; turn it off in projects that never touch Redline.
  • MCP clients confirm each tool call by default. Leave that on until you have watched what the redline mcp server does with a few real requests.

Available tools

ToolWhat it does
redlinecommand not found: run python -m pip install redline-ai, then
RedlineMiddlewarecapture bounded JSON FastAPI or ASGI request/response pairs locally, with optional skip diagnostics.
redline-mcplet AI coding assistants run checks inside Claude, Codex,
usesgowtham0992/redline@v0.3.0
selfcontained HTML for side-by-side inspection, including feature and prompt eval tables
ProofCommand or data
DashboardHTML report
SignalExample regression
KeyPurpose
suiteSuite baseline path, default redline-suite.json.
max_casesMaximum representative cases selected for a suite.
replayCommand used by eval; prompts go to stdin by default. {prompt} is for small legacy argv runners; {prompt_file} passes a temporary rendered-prompt file path.
workersNumber of replay cases to run concurrently.
ownersOptional pattern-to-owner rules so regressions show the responsible team.

How to install the Redline MCP server

{
  "mcpServers": {
    "redline": {
      "command": "uvx",
      "args": ["redline-ai"]
    }
  }
}

Add to claude_desktop_config.json, then restart Claude Desktop.

Example prompts to try

  • Use Redline to redline.
  • Use Redline to RedlineMiddleware.
  • Use Redline to redline-mcp.

Frequently asked questions

It connects Redline to MCP-compatible AI assistants such as Claude and Cursor, exposing 14 tools (redline, RedlineMiddleware, redline-mcp, and more) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with Redline directly.