# Platform Lydian

> Multi-tenant administrative platform API: people, events, documents, billing,
> and communications behind one tenant-scoped API, with tenant-defined schemas
> composed from versioned attributes. Operator-provisioned: you receive a tenant
> id and an `X-API-Key` from the platform operator; there is no self-serve signup.

Every docs page below is plain Markdown — fetch it directly, no rendering needed.
Paths are relative to the site root (https://platformlydian.com).

## Docs

- [Core concepts](/docs/concepts.md): The mental model — tenancy and isolation, attributes composed into types, the five record kinds, and how they interconnect. Read this first.
- [Quickstart](/docs/quickstart.md): Zero to a created-and-read-back record: authenticate, define a schema, create a person, read it back.
- [Authentication & conventions](/docs/conventions.md): API keys and the acting-person header, the error envelope and its stable codes, timestamps, response-shape rules — and the explicit list of what is NOT implemented (no pagination, no idempotency keys, no rate limits, no webhooks).

## How-to guides

- [Model your domain](/docs/model-your-domain.md): Design attributes, compose them into types, and evolve a schema safely.
- [Manage a document](/docs/manage-a-document.md): Roles and the bootstrap rule, check-out/check-in versioning, grants, full-text search, and the audit trail.
- [Generate an invoice from events](/docs/invoice-from-events.md): Fee attributes on events, from-events line-item generation, the invoice lifecycle, and payments.
- [Work with the inbox](/docs/work-with-the-inbox.md): Messages, threads, read state, notifications — including the system notifications the platform emits on its own.

## Reference

- [OpenAPI spec (YAML)](/openapi.yml): The complete machine-readable API reference — every endpoint, schema, enum, and description. Also at /openapi.json.
- [Interactive reference](/docs/): Swagger UI over the same spec (JS-rendered; agents should prefer the raw spec above).