Project configuration (rcas.yaml)

rcas.yaml tells the rcas command where a project keeps its rules and what to do with them. rcas init writes one.

rcas.yaml tells the rcas command where a project keeps its rules and what to do with them. rcas init writes one. Commands look for rcas.yaml, rcas.yml or rcas.json in the working directory and each directory above it; --config or RCAS_CONFIG names one explicitly. Relative paths in it are relative to the file. Every member except rcas is optional, and an unknown member is an error (exit status 3), so a typo cannot be silently ignored.

rcas: 1                         # the version of this file's format
project:
  name: Acme Payments
  idPrefix: acme.payments       # ruleset ids start with this; derived rulesets use <idPrefix>.generated
rules:
  dir: rules                    # where *.ruleset.yaml files are (default: rules)
  include: ["**/*.ruleset.yaml"] # optional globs under dir; default: every *.ruleset.yaml, .yml, .json
output:
  dir: build/rules              # where 'rcas compile --all' writes (default: build/rules)
  manifests: [client]           # also write <id>.<channel>.manifest.json for these channels
languages: [ts, java]           # ts, python, java, go, other: the runtimes that load the bundles
channels: [client, server]
sources:                        # the API descriptions rules are derived from
  openapi:
    - { path: api/openapi.yaml, schemas: [Transfer, Customer], idPrefix: acme.payments.generated }
  jsonSchema:
    - { path: schemas/order.schema.json, pointer: /$defs/Order, entity: Order }
analyze:
  include: ["src/**"]           # globs for 'rcas analyze'; ** matches directories
  exclude: ["**/test/**", "**/*.test.*", "**/*_test.go"]
  maxFiles: 20000
mcp:
  readOnly: false               # true: the MCP server offers no propose_ruleset tool
proposals:
  dir: .rcas/proposals          # where proposals wait for review (keep it out of version control)

Member	Used by	Meaning
`rcas`	every command	must be `1`
`project.name`, `project.idPrefix`	`init`, `analyze --derive`	the project's name and the prefix of its ruleset ids
`rules.dir`, `rules.include`	`check`, `test`, `compile --all`, `mcp`, `doctor`	the rulesets of the project. `RCAS_RULES_DIR` overrides `dir`
`output.dir`, `output.manifests`	`compile --all`	where bundles and manifests go. `RCAS_OUT_DIR` overrides `dir`
`languages`	`init`, agent instructions	the runtimes that load the rules: `ts`, `python`, `java`, `go`, `other`
`channels`	documentation of intent	`client` and/or `server`
`sources.openapi`, `sources.jsonSchema`	people and agents	the API descriptions to derive from; `rcas derive` takes them as arguments
`analyze.include`, `analyze.exclude`, `analyze.maxFiles`	`analyze`, `init --from`, the MCP `analyze` tool	what to scan
`mcp.readOnly`	`mcp`	leave out `propose_ruleset`
`proposals.dir`	`proposals`, `derive --propose`, `analyze --derive`, `mcp`	where proposals are stored

Commit rcas.yaml. Keep .rcas/ out of version control (rcas init adds it to .gitignore).