Project configuration (config.yaml)
Every field of openspec/config.yaml: the schema, context, and rules this project plans with.
Location
Each OpenSpec project keeps its config file at openspec/config.yaml, in the project root.
Fields
| Key | Type | Required | Effect |
|---|---|---|---|
schema | string | Yes | The workflow schema this project's changes follow |
context | string | No | Injected into every artifact's instructions |
rules | map: artifact ID → list of strings | No | Extra rules added to one artifact's built-in guidance |
operations | map: operation → guidance list | No | Advisory guidance for apply and archive work |
store | string | No | Fallback OpenSpec root when this openspec/ is config-only |
references | list | No | Stores whose specs are indexed into instructions |
Invalid fields never fail a command: each field is validated on its own, and a bad value is dropped with a warning.
What to write in these fields is covered in Project configuration.
schema
The workflow schema every change in this project follows. Valid values are spec-driven or a schema name the project defines; the names are listed in Schemas.
context
Free text injected into every artifact's instructions. The limit is 50KB; a larger value is ignored with a warning.
rules
Extra rules for one artifact, added to the schema's built-in guidance:
rules:
proposal:
- Keep proposals under 500 wordsArtifact IDs are not restricted to the built-in names, so artifacts from custom schemas work as keys.
operations
Advisory guidance for how apply and archive work is conducted, separate from artifact rules:
operations:
apply:
guidance:
- Keep test summaries conciseOnly apply and archive are read.
store
A store id used as the OpenSpec root, consulted only when this openspec/ directory is config-only (no specs/ or changes/). It is a fallback, never an override; the full ladder is Root resolution.
references
Store ids whose specs this project's work draws on. An index of each store's specs (id, summary, fetch command) is added to instructions output; spec content is never inlined, and root resolution is never affected. An entry is a store id or a map with id and an optional remote clone source:
references:
- platform-specs
- id: billing-specs
remote: git@github.com:acme/billing-specs.gitExample
A filled-in config.yaml:
schema: spec-driven
context: |
Tech stack: TypeScript, React, Node.js
We use conventional commits
Domain: e-commerce platform
rules:
proposal:
- Keep proposals under 500 words
- Always include a "Non-goals" section
tasks:
- Break tasks into chunks of max 2 hours
operations:
apply:
guidance:
- Keep test summaries concise
archive:
guidance:
- Summarize the archive outcome before finishingLegacy names
openspec/config.yml is read as an alias when config.yaml does not exist. When both files exist, config.yaml wins and config.yml is ignored. openspec init creates config.yaml.