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cmux Backend
Core rules
- Default backend TypeScript to Effect under
web/app/api/**,web/services/**, and backend scripts touching providers, databases, auth, rate limits, retries, timeouts, or telemetry. - Keep Next route handlers thin: parse the request, run one Effect program at the boundary, map typed errors to HTTP responses, treat unexpected defects separately.
- Plain TypeScript is for trivial data shapes, constants, config files, frontend React, and small glue where Effect would add ceremony without improving failure handling.
- Cloud VM backend logic stays in Vercel route handlers and Effect services backed by Postgres. Do not reintroduce Rivet or a raw actor protocol unless a later architecture doc explicitly changes the control plane.
- Postgres is the source of truth for VM lifecycle, active VM limits, idempotency, and usage events.
- Production and staging Cloud VM Postgres use the Vercel Marketplace AWS Aurora PostgreSQL OIDC/RDS IAM path, with runtime env
CMUX_DB_DRIVER=aws-rds-iam,AWS_ROLE_ARN,AWS_REGION,PGHOST,PGPORT,PGUSER,PGDATABASE. - Run production/staging migrations with
bun db:migrate:aws-rds-iam; never from Vercel build or route startup. Local dev keeps theCMUX_PORT-derived Docker Postgres path frombun dev. - Cloud VM create pricing gates use Stack Auth team payment items when enabled.
Secrets
Cloud VM build, test, and local dev scripts read provider secrets from ~/.secrets/cmux.env: FREESTYLE_API_KEY and the R2 upload vars web/scripts/build-cloud-vm-images.ts needs when creating Freestyle snapshots.
bash
set -a
source ~/.secrets/cmux.env
set +a~/.secrets/cmuxterm-dev.env holds local Stack/web env and not the provider build keys. bun dev sources ~/.secrets/cmux.env first when present, then ~/.secrets/cmuxterm-dev.env, so cmuxterm-specific Stack settings override broader cmux secrets. The web dev loader still accepts the legacy ~/.secret/cmuxterm.env and ~/.secrets/cmuxterm.env paths while machines migrate.
Detailed references
- references/effect-boundaries.md: route handlers, services, typed errors, retries, dependency injection.
- references/cloud-vm-control-plane.md: VM lifecycle, migrations, Postgres, provider idempotency, pricing gates.
