ResiliReplay

ResiliReplay is a local MCP server that runs bounded, deterministic reliability tests against MCP servers and turns failures into executable regression tests.

What you can do

Run a bundled demo that reproduces a deterministic failure, retries once, and records duplicate effects without any config or credentials. Test a reviewed MCP server from a config file with a dry-run plan, then execute it after approval by plan hash. Tune runs with JSON output, output paths, regression toggling, timeouts and retry limits. Generate and execute regression tests from causal failures and print an evidence digest. Keep the existing audit workflow and persist evidence as metadata and hashes.

When to use it

Use it when you want to check how an MCP server behaves under injected failures, verify bounded recovery and absence of duplicate effects, or turn observed failures into repeatable regression tests before relying on that server.

Requirements

Runs locally over stdio via npx from the npm package resilireplay. Node.js 22 or 24 is supported. Testing a real server needs a config file and server name; no account, credential, paid model or remote target is required for the demo.