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.
Run the installed package with Node.js 24.13.0 or newer, or Bun 1.3.13.
Bun is not required for Node users. Native isolation uses macOS sandbox-exec
or Ubuntu bubblewrap and socat. Contributors keep Bun 1.3.13 for development,
builds and tests, plus Node 24.13.0 and npm for package acceptance.
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
npm 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.
Then follow the demo-to-iteration workflow: initialize real assertions, prepare, execute, read progress and inspect the latest result.
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 the Sevro repository 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.