v0.2.1

A documentation-only maintenance release. It republishes the corrected README
to npm, whose package pages retain the README bundled with each immutable
version. There are no engine, API or dependency changes.

Fixed

• The README now identifies v0.2.1 as the current release, points source
  validation at the current tag, scopes process-crash recovery to confirmed
  state held by WalTaskStore, and documents both verified SDK era-gate
  workarounds instead of reverting to the obsolete claim that only transport
  rewriting works.

Changed

• The optional 0.3.0 client driver is now explicitly gated on upstream
  clarity around A6/A10 or demonstrated user need, so an SDK workaround does
  not become public API merely because 0.2.0 has shipped.

v0.2.0

The first release published over OIDC with a provenance attestation. No engine
code changed since 0.1.0: what changed is the runnable evidence that the
central claim holds, and a correction to what the shipped documentation says
about the official SDK.

Added

• examples/crash-recovery/: a real MCP server whose deferred task outlives
  its process. One command starts it, defers work through tools/call, kills
  the server with SIGKILL, starts it again and reads the finished result back
  from the new process. It asserts the recovered status and result rather than
  narrating them, and it runs on every pull request, so it cannot quietly stop
  being true. The README links a recording of it.
• examples/conformance-reproductions/: frozen reproductions of the three
  upstream behaviours reported from this repository, pinned to
  @modelcontextprotocol/* 2.0.0. Each one asserts its own finding, so it
  fails when upstream fixes it — reported as
  ext-tasks#14,
  typescript-sdk#2637
  and a reproduction on
  typescript-sdk#2598.

Fixed

• The README banner now resolves on the npm package page. 0.1.0 shipped a
  repository-relative path that only rendered on GitHub, and npm freezes a
  published README, so the fix could not reach that version.

Changed

• The SDK compatibility profile in docs/contract.md and docs/internals.md
  now records two verified workarounds for tasks/get and tasks/cancel
  instead of one. Answering those requests above the SDK, in HTTP middleware,
  sidesteps the protocol-era gate rather than working around it, and is the
  better starting point for a host; the transport.onmessage rename still
  works. An earlier revision called the rename "the only verified escape",
  which was assumed rather than measured.

v0.1.0

First public release. The GitHub tag and Release are followed by the one-time
manual npm publication used to establish the package; automated trusted
publishing with provenance starts with the next version.

Added

• Stable isTaskEntryTooLargeError() and isConcurrentUpdateError() guards
  for recognising errors across duplicated packages and separate CJS bundles.
• The lifecycle engine, in-memory store, typed input round-trip, TTL handling,
  CAS retries and schema-safe wire projection.
• WalTaskStore on the mcp-durable-tasks/wal entry point: durable across
  process restarts, with an in-memory read index and a write-ahead log that
  replays on open. process-wal stays an optional peer, so the main entry
  point still costs no dependencies.
• The vendored ext-tasks schema, pinned by blob SHA, plus
  pnpm check:schema to detect and refresh upstream drift.
• An English repository contract for scope, invariants, conformance decisions
  and version boundaries, plus docs/api.md, docs/durability.md and
  docs/internals.md; all four are shipped in the package for offline use.
• Crash tests over real child processes and real SIGKILL, covering task
  creation, a parked input round, an instant-terminal completion, a kill during
  appends, a compaction loop, and a TTL that elapsed while nothing was running.
  The append child reports an acknowledged version as a recovery lower bound;
  the compaction child reports a complete multi-task snapshot. They run against
  the built package rather than the sources.
• The store conformance kit on mcp-durable-tasks/testing:
  runTaskStoreConformance() declares the suite in your own runner, and
  checkTaskStore() returns a report without needing one. It carries no
  dependencies and passes against both included stores.
• Regression coverage for prototype-named input keys, losing CAS candidates,
  waiter registration, terminal/TTL settlement and public API boundaries.
• A fast-check state-machine suite that generates progress, TTL and clock
  schedules, input rounds, cancellation, terminal races and foreign CAS
  conflicts, checking record/wire parity and exactly-once waiter effects after
  every operation.

Fixed

• Protocol results now carry their required discriminator: task creation uses
  resultType: "task", while get, update and cancel use
  resultType: "complete".
• Valid JSON containing -0 is canonicalised to 0 before either store
  mutates, keeping live state, worker responses and WAL replay identical.
• Task results, errors, input payloads, and direct store records now reject
  non-JSON trees before mutation, keeping memory and WAL replay identical.
• Automatic WAL compaction failures no longer make an already-durable mutation
  appear rejected. They are observable through onCompactionError, and a WAL
  poisoned during snapshot writing fails the next store operation explicitly.
• Input waiters now register before input_required becomes observable and
  settle only from committed writes.
• Terminal results and store snapshots no longer share mutable references with
  callers.
• Invalid TTLs and malformed MCP input requests/responses are rejected before
  they can create an unreadable or unfulfillable task. Validation now follows
  nested sampling content blocks, primitive elicitation schemas and response
  values rather than accepting any JSON object at those boundaries.
• MCP input validation now follows the SDK 1.30.0 source for URL elicitation
  ids and URLs, integer token limits, Base64 content, tool schemas and task
  support metadata, and file:// roots.
• Corrupt status-specific records fail loudly instead of fabricating empty
  result, error or input payloads.
• The public conformance kit no longer produces false greens for durability,
  missing runner capabilities or hanging stores. Optional reopen() exercises
  cross-instance persistence through a complete partial-input round, skips are
  delegated to the runner, operations have finite deadlines, and cleanup
  failures remain visible.
• WalTaskStore now uses an explicit 8 MiB task-record default instead of
  inheriting process-wal's 1 MiB event default. Oversized writes surface as
  TaskEntryTooLargeError with code ERR_ENTRY_TOO_LARGE before mutation, so
  workers can retry completion with a bounded result.

Changed

• Development, CI, packaging and the lockfile now use pnpm 11.21.0. Dependency
  install scripts are denied by default; only esbuild is explicitly allowed.
• defaultPollIntervalMs: null now omits the optional wire hint; undefined
  continues to select the 1,000 ms default.
• Public documentation links now target the packed English contract instead
  of private planning drafts.
• CAS conflicts are recognized by error name in both the lifecycle and
  conformance kit, so duplicated package installations do not break retries.
• TaskPatch now explicitly applies enumerable own string-keyed properties;
  the conformance kit pins that boundary alongside undefined deletion.
• Conformance factories are now required to return a fresh store instance per
  check; duplicate creates, pure reads, input bookkeeping and exact sweep
  deletion are checked against the complete persisted state.
• Worker coordination is explicitly process-local; multi-instance hosts need
  request affinity or external coordination for live workers.
• TaskPatch now documents undefined as deletion for every store.
• Durable mutation execution now lives in an internal TaskMutator: terminal
  guards, monotonic timestamps and bounded CAS retries have one owner, while
  TaskLifecycle remains responsible for protocol decisions and committed
  worker effects.