shadow-canary

Shadow-permanent 1% + SLO-gated canary ramp for Next.js on Vercel.

• master branch → always deployed to a shadow slot receiving 1% of production traffic.
• production branch → deployed as a canary that ramps 0 → 100 % over ~5 hours, gated by /api/slo health checks. Auto-rollback on failure, with sticky sessions tied to the previous deploy so in-flight checkouts finish cleanly.
• Full admin dashboard at /admin with pause / resume / cancel / promote / 1-click rollback.
• Operable from Claude Code via a dedicated skill (/shadow-canary:status, /shadow-canary:rollback, ...).

Install

On an existing Next.js project (recommended) — let Claude Code do it:

Install shadow-canary by following https://mus-inn.github.io/shadow-canary/llms-install.md

Or read docs/install/via-claude-code.

Greenfield — use this repo as a GitHub template or clone examples/greenfield.

Manual install — follow docs/install/migration-manual.

Packages

Package	Purpose
@dotworld/shadow-canary-core	Runtime: middleware composer, Edge Config helpers, Vercel API, HMAC session.
@dotworld/shadow-canary-templates	File payload copied into target projects.
@dotworld/shadow-canary-skill	Claude Code skill (slash commands) for operating the canary.

Documentation

https://mus-inn.github.io/shadow-canary/

License

MIT