# Changelog for clickhouse-migrate
## 0.2.0.0 — 2026-11-08
### Breaking Changes
- Add public checksum, target-error, transport-error, ledger-error, history and
run-error constructors; update exhaustive matches for replicated states.
- Add checksum v2, SQL envelope v2 and replicated ledger initialization and
completion policies. Replicated targets require v2; direct targets retain v1.
### New Features
- Validate single-shard replica-set targets and replica identity on new connections.
- Support replicated MergeTree SQL, topology-specific preflight, structurally
validated replicated ledgers and full-replica quorum completion.
- Expose topology and per-format checksum accessors.
- Admit exact Altinity `26.3.60.10001.altinitystable` and
`26.3.60.10002.altinitystable` Linux arm64 engines.
### Other Changes
- Centralize server policy and add checksum v2 reference vectors, public API
checks and replicated contract documentation.
## 0.1.0.0 — 2026-10-16
Initial release.
### New Features
- Validated, ordered migration definitions and plans built through public smart
constructors, with exact SQL byte preservation and a constrained statement
envelope (`ClickHouseMigrate.Definition`, `ClickHouseMigrate.Plan`).
- Checksum v1: context-aware SHA-256 over immutable plan views, verified against
independent test vectors.
- Explicit component catalogs separated from an explicit execution schedule, so
components can be upgraded under a declared migration order.
- Conservative direct HTTP transport to ClickHouse with validated, application-owned
`TargetConfig` and no implicit credentials (`ClickHouseMigrate.Target`).
- Immutable ledger events with guarded bootstrap, qualified uncertain appends,
guarded reconciliation and complete-history reads with bounded row decoding
(`ClickHouseMigrate.Ledger`, `ClickHouseMigrate.Event`).
- Externally serialized exclusive administrative access
(`ClickHouseMigrate.ExclusiveAccess`).
- Execution (`up`), status, history and verify with scoped evidence; uncertain
work blocks ordinary `up` (`ClickHouseMigrate.Runner`,
`ClickHouseMigrate.Inspection`, `ClickHouseMigrate.Report`).
- Evidence-guarded repair and recovery that validate complete recovery events
before any mutation (`ClickHouseMigrate.Repair`).
- Source-neutral legacy history adoption preserving reviewed source evidence and
native baselines (`ClickHouseMigrate.Adoption`).
- Asynchronous cancellation propagates after bounded cleanup.
Qualified against ClickHouse 26.8.28.14 LTS (official Apple Silicon macOS binary).