v0.9.0a4 — preview alpha

Published artifacts:

• PyPI: pip install --pre stigmem-py==0.9.0a4 (also: stigmem, stigmem-node, stigmem-openclaw)
• npm: npm install @eidetic-labs/stigmem-ts@0.9.0-alpha.4
• GHCR: docker pull ghcr.io/eidetic-labs/stigmem-node:0.9.0a4 (also :0.9.0-alpha.4)
• Supply-chain evidence: GHCR image is keyless-signed with Sigstore/cosign; SBOM and BuildKit provenance are attached as OCI referrers. Verification instructions: https://docs.stigmem.dev/operators/release-verification
• GPG signatures: The release tag is maintainer-signed. Detached artifact signatures may be uploaded manually after publication.

---

[0.9.0a4] — 2026-05-22

Status: preview alpha — pre-stable, not for production federation across
organizational boundaries. Time-travel historical reads remain experimental,
opt-in, and operator-gated.

Per-ecosystem version strings (per ADR-019):

• PyPI / Python: stigmem 0.9.0a4, stigmem-py 0.9.0a4, stigmem-node 0.9.0a4, and stigmem-openclaw 0.9.0a4 (PEP 440).
• npm / Node: @eidetic-labs/stigmem-ts@0.9.0-alpha.4 (semver).
• GHCR: ghcr.io/eidetic-labs/stigmem-node:0.9.0a4 and :0.9.0-alpha.4.
• Git tag, GitHub release, prose: v0.9.0a4 (shorthand).

Changed

• Advanced the enforced release-version surfaces to the v0.9.0a4 alpha line
  across Python packages, npm packages, API metadata, conformance metadata,
  plugin compatibility defaults, release documentation, and current-facing
  adopter guidance.
• Validated v0.9.0a4 time-travel behavior: as_of remains experimental and
  opt-in behind stigmem-plugin-time-travel, requires explicit operator gates,
  fails closed by default, and now has aligned feature, compatibility,
  security, and public-doc projections for the a4 release horizon.

Security

• Validated the time-travel read path against tombstone and legal-hold
  disclosure risks: historical reads suppress tombstoned facts retroactively
  and non-admin callers do not receive legal-hold existence signals.
• Closed R-18 federation valid_until extension rejection. Federation ingest
  now compares incoming valid_until against the locally stored value on
  re-ingest and raises FederationValidUntilExtensionError when the incoming
  value would extend visibility beyond the locally observed bound. Rejections
  emit a federation_valid_until_extension_rejected audit event with stored
  and incoming values for forensic inspection. Combined with local source-trust
  recomputation, R-18 is now closed.
• Consolidated is_admin_caller derivation across as_of recall and
  fact-query paths to consistently use Identity.is_admin().
• Tightened plugin handler docstrings in stigmem-plugin-time-travel to
  clarify the gate-only role and prevent duplicate authorization at the wrong
  layer.
• Removed orphan retention_floor configuration from the time-travel plugin;
  retention floor remains a single core setting
  (STIGMEM_AS_OF_RETENTION_FLOOR).
• Remediated maintainer-audit finding NF-A1 / PYSEC-2026-161 before a4
  publication by adding an explicit starlette>=1.0.1 node dependency floor
  and refreshing uv.lock from starlette 1.0.0 to 1.0.1.
• Retained the standing advisory publication policy: Critical and High
  vulnerabilities use GHSA where applicable after a patched artifact is
  available; Medium and Low findings remain in SECURITY.md unless a
  documented carve-out applies.