# Developer Docs

**Audience:** contributors, maintainers, and coding agents

This is the contributor-facing entry point. These docs explain architecture,
invariants, implementation contracts, test ownership, and upstream Lance
constraints. User-facing behavior should still be documented through
[docs/user/index.md](../user/index.md) and the relevant public reference docs.

## Required For Every Non-Trivial Change

| Need | Read |
|---|---|
| Architectural rules, known gaps, deny-list | [invariants.md](invariants.md) |
| Upstream Lance source-of-truth index | [lance.md](lance.md) |
| Existing test coverage and test placement | [testing.md](testing.md) |

## Architecture And Storage

| Area | Read |
|---|---|
| System structure, L1/L2 framing, component diagrams | [architecture.md](architecture.md) |
| On-disk layout, manifest schema, URI behavior | [storage.md](../user/storage.md) |
| Direct-publish writes, D2, staged writes, recovery sidecars | [writes.md](writes.md) |
| Query execution, mutation execution, loader flow | [execution.md](execution.md) |
| Index lifecycle and graph topology indexes | [indexes.md](../user/indexes.md) |
| Branch and commit internals | [branches-commits.md](../user/branches-commits.md) |
| Three-way merge implementation and conflicts | [merge.md](merge.md) |
| Diff/change-feed implementation | [changes.md](../user/changes.md) |
| Branch protection policy | [branch-protection.md](branch-protection.md) |
| CODEOWNERS source of truth | [codeowners.md](codeowners.md) |

## Language, Runtime, And Boundaries

| Area | Read |
|---|---|
| Schema grammar, catalog, migration planner | [schema-language.md](../user/schema-language.md) |
| Query grammar, IR, lints, mutation restrictions | [query-language.md](../user/query-language.md) |
| Embedding client and `@embed` integration | [embeddings.md](../user/embeddings.md) |
| Cedar policy surface and server gating | [policy.md](../user/policy.md) |
| Server auth, OpenAPI, endpoint handlers | [server.md](../user/server.md) |
| Error taxonomy and serialization | [errors.md](../user/errors.md) |
| Constants and tunables | [constants.md](../user/constants.md) |
| Transaction model public contract | [transactions.md](../user/transactions.md) |

## Project Operations

| Area | Read |
|---|---|
| CI and release workflows | [ci.md](ci.md) |
| Install and deployment packaging | [install.md](../user/install.md), [deployment.md](../user/deployment.md) |
| Release history | [releases/](../releases/) |

## Contribution & Governance

| Area | Read |
|---|---|
| How to contribute (external) | [CONTRIBUTING.md](../../CONTRIBUTING.md) |
| Governance model, roles, decision authority | [GOVERNANCE.md](../../GOVERNANCE.md) |
| Public contribution RFC track | [rfcs/](../rfcs/) |

The `docs/rfcs/` track is the **public, externally-authorable** RFC process. The
maintainer/internal RFCs below (`rfc-00N-*.md`) are a separate, team-owned
track; don't conflate the two.

## Active Implementation Plans

Working documents for in-flight feature work. Removed when the work lands.

| Area | Read |
|---|---|
| Schema-lint chassis v1 (MR-694) — `--allow-data-loss`, soft/hard drops | [schema-lint-v1-plan.md](schema-lint-v1-plan.md) |
| Inline + stored queries, request/response envelope, MCP (MR-656 / MR-976 / MR-969) | [rfc-001-queries-envelope-mcp.md](rfc-001-queries-envelope-mcp.md) |
| Config & CLI architecture — layered config, client targeting, file naming (MR-973 / MR-974 / MR-981) | [rfc-002-config-cli-architecture.md](rfc-002-config-cli-architecture.md) |
| MCP server surface — full tool parity, stored queries, modular auth (MR-969 / MR-956 / MR-974) | [rfc-003-mcp-server-surface.md](rfc-003-mcp-server-surface.md) |
| Future cluster control plane — declarative as-code config, JSON state ledger, reconciler | [cluster-config-specs.md](cluster-config-specs.md), [cluster-axioms.md](cluster-axioms.md), [cluster-config-implementation-spec.md](cluster-config-implementation-spec.md) |
| Cluster graph & schema apply — Phase 4 sidecars, roll-forward recovery, approval artifacts | [rfc-004-cluster-graph-schema-apply.md](rfc-004-cluster-graph-schema-apply.md) |
| Server boots from cluster state — Phase 5 mode switch, applied-revision serving | [rfc-005-server-cluster-boot.md](rfc-005-server-cluster-boot.md) |
| Per-operator config — `~/.omnigraph/` identity, keyed credentials, named servers (the operator slice of RFC-002) | [rfc-007-operator-config.md](rfc-007-operator-config.md) |
| Deprecate `omnigraph.yaml` — one concern per config surface; key-by-key migration map and staged retirement | [rfc-008-deprecate-omnigraph-yaml.md](rfc-008-deprecate-omnigraph-yaml.md) |

## Boundary

Developer docs may mention implementation details, stale gaps, upstream Lance
blockers, and review rules. User docs should not require that context unless
the detail changes the public contract.
