Roadmap

Current release: v1.0.0. Stable SemVer for the public API frozen in 0.12.

Done in 0.1.0

• Mongo-backed immutable event log
• Bounded fetch + leases + ACK
• Crash/redelivery + stale lease fencing
• Competing consumers
• Independent consumer groups
• Historical query
• Idiomatic Rheo.Consumer
• Bounded demand (max_demand)
• Demo + docs/tutorials
• Livebook demo (notebooks/rheo_demo.livemd)

Done in 0.2.0

• Named multi-instance Rheo + opaque backend handles
• Local Rheo.Group runtime (demand, concurrency, renew, drain)
• Portable Rheo.Query; Event codec moved to Mongo
• Explicit persistence-error telemetry / settle semantics
• Migration guide + Article 9

Done in 0.3.0

• Rheo.Backend.ETS (ephemeral, per-instance tables)
• Backend capabilities map
• Shared conformance suite (ETS always; Mongo tagged)
• Docker-free demo / Livebook path
• ADRs 011, 012, 014 + Article 10

Done in 0.4.0

• Query sequence bounds, query_page / stream_query
• Replay / reset_group (no event copies); create_group start cursors
• Rheo.Event.Lineage conventions
• ADR 015 + Article 11 + 0.3 → 0.4 migration

Done in 0.4.1

• Hex README links use HexDocs / GitHub absolutes (relative docs/ paths 404 on hex.pm)

Done in 0.5.0

• Configurable partitions + :erlang.phash2/2 key routing
• Per-partition sequences; ordered consume within a partition only
• Contiguous ACK frontier + Rheo.lag/3
• Static Group/Consumer :partitions assignment (no auto-rebalance)
• Partition-scoped replay / reset_group
• ADR 016 + Article 12 + 0.4 → 0.5 migration
• Docs/Livebook/CHANGELOG links use absolute HexDocs or GitHub URLs for hex.pm

Done in 0.6.0

• Rheo.Backend.Ecto on host-owned Repo (PostgreSQL + SQLite)
• SQL migrations + mix rheo.ecto.gen_migration
• Postgres FOR UPDATE SKIP LOCKED; optional NOTIFY
• SQLite durable single-node path; distributed: false
• ADR 017 + Article 13 + 0.5 → 0.6 migration

Done in 0.7.0

• Rheo.Producer — GenStage producer emitting %Rheo.Lease{} (demand → fetch, inflight renewal, idle poll, backoff, drain)
• Rheo.Broadway.transform/2 + Rheo.Broadway.Acknowledger (ack / nack / reject)
• Rheo.Producer.confirm/2 so settled leases stop renewing and free demand
• Rheo.Consumer / Rheo.Group unchanged — the producer is an alternative surface
• ADR 018 + Article 14 + 0.6 → 0.7 migration

Done in 0.7.1

• HexDocs sidebar groups for guides, design, and migrations (later slimmed in v0.11 to current docs only; archive stays on GitHub)
• Mermaid diagrams render on HexDocs
• Livebook Broadway demo aligned with the published v0.7 API

Done in 0.8.0

• Architectural reset (ADR 019): read-only handler context and one Group owner per {rheo, stream, group} (ADR 022); lease receipt (ADR 021); typed capabilities (ADR 023); semantic backend contract and settlement vocabulary (ADR 024); Rheo.Inflight / Rheo.Backoff shared by Group and Producer
• Rheo.Producer.ack/3, nack/4, reject/4 — one-call settle and release
• Conformance suite grouped by guarantee, run by ETS, Mongo, Ecto, and a native-stream double; failure-injection and property tests on ETS
• Optional integrations with compile-time guards and a core-only build check; Flow and Redis readiness spikes
• ADRs 019–025; Article 15; 0.7 → 0.8 migration

Done in 0.9.0

• Rheo.Backend.Redis on optional redix (ADR 026) — Model C sequences + native receipts, fenced XACK, reclaim, replay
• Wakeup contract implemented (ADR 025): reader Task + wait/2; polling remains fallback
• Conformance suite tagged :redis; docker-compose Redis 7 service
• 0.8 → 0.9 migration; Redis guide
• Article 16 (portable sequence, native PEL)

Done in 0.10.0

• Ops surface (ADR 027): DLQ listing, stream/group inventory, group health, telemetry metrics helpers, optional LiveDashboard, Mix inspect tasks, formalized benchmarks
• 0.9 → 0.10 migration

Done in 0.11.0

• Rheo.Backend.Mnesia — durable ETS-shaped OTP :mnesia store, single-node disc_copies (durable: true, distributed: false) (ADR 028)
• Multi-node backend comparison documented (Redis / Postgres yes; ETS / SQLite / Mnesia v0.11 no)
• 0.10 → 0.11 migration

Done in 0.11.1

• Composite query_page cursors, single Group poll timer, Registry group names
• Shared ETS/Mnesia table engine with indexes; stream-first fetch errors
• 0.11 → 0.11.1 migration

Done in 0.12.0

• API freeze candidate (ADR 029): HexDocs publishes Facade / Consume / Values / Backend / Runtime / Ops; internal modules filtered
• Public API guide; unavailable-handle contract case; Metrics coverage
• 0.11.1 → 0.12 migration

Done in 1.0.0

• SemVer baseline for the frozen surface (ADR 030)
• 0.12 → 1.0 migration — no intended breaks from 0.12.0

Next (post-1.0)

• Multi-node Mnesia table copies (backend arbitration only — not a Rheo cluster)
• Article candidate: Rheo + Flow settlement narrative

Explicitly deferred

• Distributed Rheo cluster coordination (beyond durable backend arbitration)
• Automatic partition rebalancing
• Cross-region replication
• Exactly-once claims
• Transactional consume-and-produce
• Schema registry
• Custom wire protocol
• Administrative web UI
• Kubernetes operator
• AuthN/AuthZ frameworks
• Multi-tenancy
• Retention tiers
• Standalone Rheo server
• mongodb_ecto as a Rheo backend path