Assign
The [assign] section controls what happens to services inside a Coast instance when you switch branches with coast assign. Each service can be configured with a different strategy depending on whether it needs a full rebuild, a restart, a hot-reload, or nothing at all.
For how coast assign and coast unassign work at runtime, see Assign.
[assign]
default
The default action applied to all services on branch switch. Defaults to "restart" if the entire [assign] section is omitted.
"none"— do nothing. The service keeps running as-is. Good for databases and caches that don't depend on code."hot"— the code is already live-mounted via the filesystem, so the service picks up changes automatically (e.g. via a file watcher or hot-reload). No container restart needed."restart"— restart the service container. Use when the service reads code at startup but doesn't need a full image rebuild."rebuild"— rebuild the service's Docker image and restart. Required when code is baked into the image viaCOPYorADDin the Dockerfile.
[assign]
default = "none"[assign.services]
Per-service overrides. Each key is a compose service name, and the value is one of the four actions above.
[assign]
default = "none"
[assign.services]
backend = "hot"
web = "hot"[assign]
default = "none"
[assign.services]
app = "rebuild"This lets you leave databases and caches untouched ("none" via the default) while rebuilding or restarting only the services that depend on the code that changed.
[assign.rebuild_triggers]
File patterns that force a rebuild for specific services, even if their default action is something lighter. Each key is a service name, and the value is a list of file paths or patterns.
[assign]
default = "restart"
[assign.rebuild_triggers]
api = ["Dockerfile", "package.json", "package-lock.json"]exclude_paths
A list of paths to exclude from worktree sync during coast assign. Useful in large monorepos where certain directories are irrelevant to the services running in the Coast and would otherwise slow down the assign operation.
[assign]
default = "none"
exclude_paths = ["apps/ide", "apps/extension", "apps/ide-extension"]
[assign.services]
backend = "hot"
web = "hot"Examples
Rebuild app, leave everything else alone
When your app service bakes code into its Docker image but your databases are independent of code changes:
[assign]
default = "none"
[assign.services]
app = "rebuild"Hot-reload frontend and backend
When both services use file watchers (e.g. Next.js dev server, Go air, nodemon) and code is live-mounted:
[assign]
default = "none"
[assign.services]
backend = "hot"
web = "hot"Per-service rebuild with triggers
The API service normally just restarts, but if Dockerfile or package.json changed, it rebuilds:
[assign]
default = "none"
[assign.services]
api = "restart"
worker = "restart"
[assign.rebuild_triggers]
api = ["Dockerfile", "package.json"]Full rebuild for everything
When all services bake code into their images:
[assign]
default = "rebuild"