Sevro

Sevro runs repeatable evaluations of coding agents. Give it a case, a host adapter, and success criteria; it retains execution, grading results, and evidence. Projects own their benchmark cases and policy through Sevro's extension boundary.

Sevro grew out of Darrow, but works without a Darrow checkout. Try your first evaluation: no model account is required.

Status and environments

Sevro is under active development. The npm package is @bjoernrochel/sevro; its command is sevro. The current release includes runtime configuration, native goals, selected plugin hooks, and the current licensing terms. Earlier rc.1 and rc.2 packages retain their original BSL grants. See installation and release differences.

Use Bun 1.3.13. The development checkout runs native isolation on macOS with sandbox-exec and on Ubuntu with bubblewrap and socat. Contributor package/release checks also need Node 24 and npm. Windows support is unverified. The basic example uses an injected deterministic adapter and needs no native model credentials.

Install and get a first result

mkdir sevro-demo
cd sevro-demo
bun init -y

Install the current release in that directory. Continue with your first evaluation: the exact command, expected passed result, and retained evidence. Read installation for updates, removal, and source checkouts.

The development checkout and freshly built packages provide a demo-to-iteration workflow: initialize real assertions, prepare, execute, read progress and inspect the latest result. The published rc.11 package uses the installed tutorial above.

Find your next task

The documentation hub routes to running evaluations, authoring cases and extensions, reading results, troubleshooting, and architecture. Public v1 contracts are the extension protocol, results and evidence, and report. Machine-readable contracts live in schemas/.

Ask the repository guide

Open this checkout in a fresh Codex or Claude Code session and ask “What is Sevro, and how do I run my first evaluation?” Explicit invocation is $sevro-guide in Codex or /sevro-guide in Claude Code. The guide reads sources, cites its answers, and handles follow-ups. It explains commands; execution requires a separate request. See the guide contract and verification limits. The npm package does not install the repository guide.

Contribute

CONTRIBUTING.md covers setup, checks, fixtures, schema regeneration, compatibility, and releases. Documentation quality defines documentation checks and review.

Run bun run check:typescript for the complete quality gate and bun run check:typescript --fast before committing. The TypeScript quality contract defines the source inventory, strict typing, property tests, coverage integrity, and supported environment.

License and acknowledgements

The current release uses the Sevro Source Available License 1.0. Use is free in every context, including commercial work and paid education. Selling copies, rebranded versions, or hosted access to Sevro's functionality requires a separate license. Modification and free redistribution remain allowed. It is source-available, not an OSI open-source license. Read licensing for contribution grants and earlier BSL releases.

Björn Rochel created the logo. Sevro's name is inspired by the character in Pierce Brown's Red Rising. Thank you, Pierce Brown, for the world and characters that inspired both Sevro and Darrow. See acknowledgements.