The migration design making object storage THE deployment model: a sealed ClusterStore interface (object_store-backed) replaces every raw-fs call in the cluster crate; cluster.yaml gains a storage: root (s3://... — state ledger via conditional-put CAS, cross-machine locking, catalog/sidecars/ approvals as objects, derived graph roots as engine-native S3 URIs); the server takes --cluster s3://... and cluster deployments become stateless (bucket, no volume). Config files stay in the working tree — Terraform's config-local/state-remote split. Local FS is demoted, not deleted: one interface, file:// as an explicit dev/test backend, S3-first everywhere in docs, storage: required at the v0.9 boundary. Grounded: conditional writes (If-None-Match and If-Match) verified live against RustFS 1.0.0-beta.8 — both probes pass; Lance 6 already commits via S3 conditional writes; Omnigraph::init/open accept S3 URIs today. Staged A-D with sizes and the migrate-storage cutover tool. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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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 and the relevant public reference docs.
Required For Every Non-Trivial Change
| Need | Read |
|---|---|
| Architectural rules, known gaps, deny-list | invariants.md |
| Upstream Lance source-of-truth index | lance.md |
| Existing test coverage and test placement | testing.md |
Architecture And Storage
| Area | Read |
|---|---|
| System structure, L1/L2 framing, component diagrams | architecture.md |
| On-disk layout, manifest schema, URI behavior | storage.md |
| Direct-publish writes, D2, staged writes, recovery sidecars | writes.md |
| Query execution, mutation execution, loader flow | execution.md |
| Index lifecycle and graph topology indexes | indexes.md |
| Branch and commit internals | branches-commits.md |
| Three-way merge implementation and conflicts | merge.md |
| Diff/change-feed implementation | changes.md |
| Branch protection policy | branch-protection.md |
| CODEOWNERS source of truth | codeowners.md |
Language, Runtime, And Boundaries
| Area | Read |
|---|---|
| Schema grammar, catalog, migration planner | schema-language.md |
| Query grammar, IR, lints, mutation restrictions | query-language.md |
Embedding client and @embed integration |
embeddings.md |
| Cedar policy surface and server gating | policy.md |
| Server auth, OpenAPI, endpoint handlers | server.md |
| Error taxonomy and serialization | errors.md |
| Constants and tunables | constants.md |
| Transaction model public contract | transactions.md |
Project Operations
| Area | Read |
|---|---|
| CI and release workflows | ci.md |
| Install and deployment packaging | install.md, deployment.md |
| Release history | releases/ |
Contribution & Governance
| Area | Read |
|---|---|
| How to contribute (external) | CONTRIBUTING.md |
| Governance model, roles, decision authority | GOVERNANCE.md |
| Public contribution RFC track | 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 |
| Inline + stored queries, request/response envelope, MCP (MR-656 / MR-976 / MR-969) | 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 |
| MCP server surface — full tool parity, stored queries, modular auth (MR-969 / MR-956 / MR-974) | rfc-003-mcp-server-surface.md |
| Future cluster control plane — declarative as-code config, JSON state ledger, reconciler | cluster-config-specs.md, cluster-axioms.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 |
| Server boots from cluster state — Phase 5 mode switch, applied-revision serving | rfc-005-server-cluster-boot.md |
| Object-storage-native migration — S3-first cluster, local-FS deprecation | rfc-006-object-storage-native.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.