> For the complete documentation index, see [llms.txt](https://docs.getlynk.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.getlynk.ai/concepts.md). # Concepts - [Overview](https://docs.getlynk.ai/concepts/concepts.md): The router — every page in these docs and what it answers. Ground vocabulary here, then read the narrowest page. - [Project](https://docs.getlynk.ai/concepts/project.md): A Lynk project is a self-contained git repository — one repo, one customer — consumed as versioned, validated builds. - [lynk.yml](https://docs.getlynk.ai/concepts/lynk-yml.md): The required project settings file at the .lynk/ root — schema\_version, topology, and name. - [LYNK.md](https://docs.getlynk.ai/concepts/lynk-md.md): LYNK.md is the agent's orientation and identity — who the business is, who a team is, and how they think. Always loaded. - [GLOSSARY.yml](https://docs.getlynk.ai/concepts/glossary.md): GLOSSARY.yml is the team's vocabulary — the terms they use and what they mean, always loaded and merged across scopes. - [Domain](https://docs.getlynk.ai/concepts/domain.md): A domain is an agent — one team's analytical surface, with its own vocabulary, entities, skills, and policies. A user talks to one at a time. - [LYNK.md (domain)](https://docs.getlynk.ai/concepts/domain/lynk-md.md): A domain's LYNK.md — who this team is. Appended to the root LYNK.md; extends it, never replaces it. - [GLOSSARY.yml (domain)](https://docs.getlynk.ai/concepts/domain/glossary.md): A domain's GLOSSARY.yml — the team's vocabulary, merged over the root glossary with the domain winning on a key collision. - [Entity](https://docs.getlynk.ai/concepts/entity.md): An entity is a lazy, encapsulated representation of a thing in the business — a folder holding an ENTITY.md prose file and a schema.yml definition. - [ENTITY.md](https://docs.getlynk.ai/concepts/entity/entity-md.md): ENTITY.md is the prose side of an entity — quirks, conventions, and business context the agent reads. Short by design, frontmatter required. - [schema.yml](https://docs.getlynk.ai/concepts/entity/schema-yml.md): schema.yml is the structured definition of an entity — identity, keys, imports, features, metrics, and relationships. - [Identity and Imports](https://docs.getlynk.ai/concepts/entity/schema-yml/identity-and-imports.md): identity roots an entity in a warehouse table or view, or another entity; keys identify its rows; imports cherry-pick definitions from a parent entity. - [Feature](https://docs.getlynk.ai/concepts/entity/schema-yml/feature.md): A feature is a queryable, row-grain attribute of an entity — a column, a derivation, or a value pulled across a relationship. - [Metric](https://docs.getlynk.ai/concepts/entity/schema-yml/metric.md): A metric is an aggregation defined on the entity it aggregates — sum, count, average, conditional aggregates — invoked with metric(). - [Relationships](https://docs.getlynk.ai/concepts/entity/schema-yml/relationships.md): Relationships declare a path from an entity to a physical table or another entity — directional, per-step joins with cardinality. - [Policy](https://docs.getlynk.ai/concepts/policy.md): Policies are eager, always-apply behavioral commitments — output format, clarification behavior, and other rules for how the agent operates. - [Skill](https://docs.getlynk.ai/concepts/skill.md): Skills are lazy prose procedures for classes of analytical reasoning — how the agent thinks through an analysis, not what exists in the data. - [Reference Files](https://docs.getlynk.ai/concepts/reference-files.md): Reference files — user-organized files outside the domain primitives, the escape hatch for cross-cutting content, reached by absolute /.lynk/ references. --- # Agent Instructions This documentation is published with GitBook. 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