First public release

Crossweft is now public, under the Apache-2.0 license. It checks the places where code in one language has to agree with code in another, and it stops an AI agent from finishing while those places disagree.

What you get

• A seam map. Blocks, links, flows and data live in a map next to your code. Every link says how it is enforced, and a hand-written seam needs a guard that reads both sides.
• Three guards. join compares every occurrence of a value, set compares two collections, and pair fingerprints two regions that must be re-attested together with a written reason.
• Checks for anchors, routes (Go chi and regex scanners), data provenance, coverage and findings. A finding goes stale once the problem it excuses is fixed.
• Agent hooks. A tested Claude Code plugin, plus experimental adapters for Codex, Gemini CLI, Copilot and Cursor. crossweft agents puts the harness into the repository, and check fails if it goes missing.
• Adoption in an existing repo. crossweft baseline records today's drift as open findings, so new drift still fails.
• CI. A GitHub Action, pre-commit hooks and SARIF output for code scanning.

Why it matters

Before release, an independent review tried to make the check pass when it should not. Every case it found was reproduced, fixed and covered by a test: silent passes from repeated JSON keys, missing files and unscannable routes now fail loudly, and "scanned nothing" is an error, never a pass.