[!NOTE] Notable implementation and specification changes are documented separately below.

🧭 Changelog Structure

This changelog maintains two independent histories:

[!IMPORTANT] Software versions and specification revisions are separate authorities and must not be interpreted as the same version sequence.

🚧 [Unreleased]

Software target: 0.2.0 Next roadmap target: 0.3.0 Release status: Unreleased Release qualification: Undergoing release qualification Published release: None

2026-09-27 — Synthetic evaluation contract foundations (Phase A complete)

• Apply the corrected consolidated v1.2.6 authority: closed Episode schema object, required null-only E2 outcome, CanonicalU64 decimal-string alias, artifact bindings and structural replay provenance. Add the full Episode wire shape and immutable wire-validated domain conversion, with negative decoding tests and positional-array rejection.
• Preserve existing planner/ranking/transport behavior. Lifecycle/collection semantics, fingerprints, runtime observation/capture and replay remain later-phase work. See the completion record.

2026-09-27 — Initial synthetic evaluation checkpoint (partial Phase A)

• Add strict canonical scalars, explicit token registries and structural manifest, run-binding, provenance and privacy components under cerebri-planner::evaluation.
• Pin the existing serde_json 1.0.151 dependency for the qualified admission-work metric; retain the lockfile and all current planner/transport semantics.
• Record ADR-0015 and the checkpoint. Phase A is incomplete: complete Episode wire definitions need clarification. No Episode construction, fingerprints, replay, Phase B or release is claimed.

2026-09-26 — Repository hardening and governance closure

• Pin the retained GitHub Traffic Stats action to immutable commit f05c995b41d817087f7f728dd1794af559d81471 (v1.0.0) and apply least-privilege workflow permissions, with contents: write limited to the traffic update job.
• Split repository qualification into independent CI gates so one policy failure no longer suppresses unrelated evidence; harden AGENTS.md scope, Git safety, qualification and release-authorization rules.
• Repair the site/docs qualification baseline with semantic figcaption markup, a scoped Release status E2E locator, deterministic Reduced Motion visual verification and reviewed Linux visual baselines.
• Remote Cerebri CI and Documentation Pages completed successfully on hardening merge 968f8a427f02bef8ed9036c56baecd9bf217ca69.
• Software remains unreleased 0.2.0; no version bump, tag or GitHub Release was created.

2026-09-26 — Ranking import parity correction (Slice 1)

• Reject imported Lab candidates whose ranking observations disagree with their candidate fields or ordering key, including the existing zero projection for missing preference.
• Add negative JSON import coverage without changing Rust ranking or schema 0.1; see the correction verification record.

2026-09-25 — Ranking observations (Slice 1)

• Add RankingFeatureSet schema 0.1 to candidate output with required-nullable preferred-start distance/source, contextual mutation count and legacy shift seconds.
• Validate missing vs null, paired nullability and schema compatibility at the Rust wire boundary. Preserve whole-second quantization and the complete deterministic ordering key.
• Carry core-produced features through REST, Node and Lab; add presence, subsecond, generated-mode/permutation and full scenario-order regression coverage.
• Document ADR-0014 and synchronized Master/DE/EN references. No CPIR/software/API version bump or release.
• Independent Math and Security qualification completed after the Slice-1 parity correction. The dated implementation verification records preserve their contemporaneous pre-qualification state and limitations; no ranking/planner semantics or schema version changed.

[!WARNING] No software release or tag has been created yet.

2026-09-22 — Release qualification corrections

Fixed

• Separated workspace 0.2.0 from unreleased qualification and publication status in current documentation and generated website metadata. No formal RC, tag, release or version bump.
• Replaced loose README version presence checks with exact authority fields, badge/footer checks and targeted stale/contradictory-metadata mutations; site generation shares these checks.
• Made CPIR 0.2 the normal Quick Start, preserved the exact former CPIR 0.1 example as a named legacy fixture, and strengthened Core/API/Node/Lab compatibility and unknown-version rejection coverage.

Security and CI

• Added pinned cargo-audit 0.22.2 lockfile scanning; known vulnerabilities, warnings and scanner failures block CI without ignored advisories. Added the explicit locked workspace build.
• Pinned all direct CI/Pages actions to upstream commit SHAs, retained exact tag comments, added weekly Dependabot updates, removed persisted checkout credentials and scoped Pages write permissions to deployment.
• Preserved short-lived synthetic browser failure evidence for review. Kept all existing deterministic planner, frontend, documentation and npm audit gates.

Documentation and governance

• Added the Accepted ADR index and subsystem-reading rule; clarified the Master's original baseline date without inventing revision dates.
• Restored exact historical specification 0.1/0.2/0.3 blobs with provenance and non-normative labeling; preserved accurate historical ADR/progress wording.
• Removed the external view counter and documented the retained informational badge policy. Documented advisory policy and the existing low-severity site dependency finding without suppressing it.
• Qualification evidence and limitations. Independent review and a later explicit release decision remain required.

2026-09-21 — Deterministic planner verification and hardening

Added

• Deterministic SplitMix64 test generator without new dependencies: 512 independent schedule seeds with integer feasibility/ranking oracles and three full-response permutations each; 256 recurrence seeds with day-by-day expectations; all 512 directed three-node graphs and 256 additional small graph seeds checked with transitive-closure and exhaustive-order oracles.
• Named malformed CPIR corpus, 128 reproducible byte-mutation cases, explicit CPIR 0.1/0.2/future-version round trips and API/Core parity. Added arithmetic, maximum-workload, DST identity/clipping and shared-budget regressions.

Fixed / Security

• Reuse the validated immutable compilation during planning instead of compiling twice and discarding the second error. Lifecycle revalidation remains independent.
• Reject unrepresentable local dates through checked timezone-offset arithmetic; extreme valid UTC JSON input no longer panics in ExplicitDate constraints.
• Bound serialized typed input, repeated request metadata work and materialized occurrence evidence (ADR-0013). Existing count/work limits remain intact; rejection is atomic.
• Lab now rejects malformed validation issue payloads and domain identifiers before rendering. Real Rust response mutations demonstrate the fixes.

Documentation / compatibility

• Confirmed ADR-0012 nominal occurrence identity: Earlier/Later share an ID while UTC ranges and resolution evidence differ. CPIR 0.1 remains distinct from temporal CPIR 0.2; unknown coverage still blocks planning.
• Updated Master, roadmap, DE/EN references and the dated verification report, including limits and remaining blind spots.
• No new dependency, schema generation, UI redesign, feature expansion, software bump, tag or release. Independent review and release qualification remain the next bounded milestone.

2026-09-21 — Deterministic planner integration

Added

• Added CPIR 0.2 temporal source input and an independently testable bounded snapshot compiler; CPIR 0.1 remains accepted without temporal input.
• Materialized existing recurrence occupancy with stable occurrence identity, full and clipped ranges, source revision, provenance, evidence and explicit DST outcomes. Duplicate series, unsafe provenance, prospective series, horizon mismatch and exhausted budgets fail closed.
• Added deterministic dependency graphs with stable topological order, missing-reference diagnostics and iterative cycle-component evidence. Graphs grant no scope, policy, capability or authorization.
• Exposed the complete lexicographic candidate ordering key; preserved single-event grid search and truthful exhaustive/budget assessments.
• Added real Lab compiler, availability, dependency and score inspection plus 11 source scenarios exercised through Core, REST and TypeScript contract guards.
• Added combined hard-constraint, independent integer-oracle, golden schedule and negative contract tests.

Architecture and compatibility

• Accepted ADR-0012 and synchronized the Master and DE/EN CPIR/planner references. ADR-0011 remains the official-site decision.
• Kept occurrences separate from mutable planning/provider objects. Lifecycle validation rechecks the same source snapshot. Recurrence constraints and prospective series remain unsupported.
• Incomplete temporal coverage blocks planning; required buffers must fit within the compiled horizon. Series reconciliation, exceptions, joint search and repair remain deferred.
• Software remains unreleased 0.2.0, specification 0.4 and REST /v1; no release or tag is created by this session.

Verification

• Exact commands, results and the interruption recovery are recorded in the session log.

📅 2026-09-20 — Official Nexus Cerebri Website

✨ Added

• Added apps/cerebri-site, a static SvelteKit/Svelte 5/TypeScript official website.
• Added public knowledge surfaces for Explore, CPIR, deterministic planning, time, safety, architecture, Lab, roadmap, developers and canonical repository documentation.
• Added global Understand / Technical / Research explanation depth.
• Added explicit REAL / EDUCATIONAL / FUTURE CONCEPT labels and text alternatives for significant visualizations.
• Added build-time website authority data derived from Cargo, the current Master, CPIR fixtures and repository Markdown.
• Added Rust-generated planner and temporal website fixtures through cerebri-core.
• Added Playwright navigation, accessibility, responsive-overflow and visual-regression coverage.

🔄 Changed

• Replaced the bespoke static documentation portal with the repository-backed SvelteKit site while keeping site/ as the Pages artifact and npm run docs:build as the canonical build command.
• Updated GitHub Pages and CI to build the official site with the /Nexus-Cerebri base path.
• Extended repository checks for site version authority, route inventory, static-host configuration, retired portal files and runtime font imports.
• Kept canonical Markdown as documentation truth and Cerebri Lab as a separate developer/research client.

🏛️ Architecture

• Added ADR-0011 for the official-site frontend strategy.
• Preserved Rust as planner/temporal authority; TypeScript contains no duplicated planning or recurrence implementation.
• Preserved Planner ≠ Executor and does not expose or simulate provider execution, production authentication, durable ledger behavior, preference learning or neural inference.

🧪 Testing

• Added Axe serious/critical accessibility checks for representative public routes.
• Added route/prerender checks plus horizontal-overflow coverage at 1440, 1024, 768 and 390 px.
• Added visual-regression capture at the same four widths.

🛠️ Development

• Retired scripts/build-docs.mjs, scripts/docs-theme.css and scripts/docs-ui.js.
• Added an official-site README and dated implementation/progress record.
• Verified the final site stack on GitHub Actions push run 35520398395 and pull-request run 35520401015; both completed successfully.
• Committed the official-site lockfile, switched CI/Pages to reproducible npm ci, updated GitHub Actions dependencies, and removed the temporary lock bootstrap workflow.
• Locked deterministic visual-regression hashes at 1440, 1024, 768 and 390 px after successful browser/Axe verification.

📅 2026-09-20 — Temporal Core, Cerebri Lab and Repository Structure

Version authority reconciliation

• Synchronized the current software target with Cargo workspace and Lab version 0.2.0.
• 0.1.0 remains the historical unreleased Foundation target; specification 0.4, CPIR 0.1 and REST /v1 are independent authorities. No release was created by this correction.

✨ Added

• Added the next Temporal Core foundation with bounded recurrence and horizon-aware temporal processing.
• Added deterministic recurrence and temporal boundary handling designed around half-open [start, end) intervals.
• Added Free/Busy foundations for future scheduling and candidate generation.
• Added additional temporal tests covering recurrence boundaries, timezone behavior, DST transitions, touching intervals and invalid temporal states.
• Added dedicated planning-scope review coverage.
• Added the next Cerebri Lab frontend foundation for developer, research and debugging workflows.
• Added a modern Nexus-inspired Lab design system with rounded surfaces, glass/blur effects, glow accents, responsive layouts and developer-focused information hierarchy.
• Added foundations for future planner visualization, structured trace inspection, semantic inspection, model output and graphical data visualization.
• Added ADRs covering documentation layout, scope and prospective-object identity, bounded temporal diagnostics and the Cerebri Lab frontend architecture.
• Added documentation describing the project's AI-assisted development workflow and the review/testing requirements applied to AI-assisted contributions.
• Added temporal example data for development and documentation purposes.

🔄 Changed

• Reorganized project documentation into a clearer docs/ hierarchy while keeping repository entry-point documents at the root.
• Moved architecture decisions into docs/architecture/decisions/.
• Moved the Master Specification into docs/architecture/specifications/.
• Moved historical review-resolution documents into docs/archive/reviews/.
• Moved roadmap, progress and agent-boundary documentation into the appropriate docs/development/ hierarchy.
• Updated documentation navigation and internal links to reflect the new repository structure.
• Updated repository and documentation checks where required by the new file organization.
• Updated CI and workspace configuration for the expanded Temporal Core and Cerebri Lab foundations.
• Advanced the project according to the current development roadmap while preserving the Foundation architecture boundaries.
• Clarified and documented Foundation review findings concerning planning scope and prospective-object identity.
• Updated API/Core integration required by the new temporal functionality.
• Updated progress and development documentation to reflect the completed work.

🏛️ Architecture

• Preserved the strong planning lifecycle: ProposedPlan -> ValidatedPlan -> ActionPlan -> AuthorizedActionPlan -> ExecutionResult.
• Preserved the rule that only AuthorizedActionPlan may enter execution.
• Preserved the separation between planning scope, capabilities, authorization, hard constraints and learned preferences.
• Preserved deterministic lower layers and the separation between production and research code.
• Preserved the distinction between epistemic knowledge states and unresolved processing state.
• Kept Cerebri Lab as a consumer and visualization surface for Core data rather than a source of planning/domain truth.
• Documented architectural treatment of planning-scope semantics and prospective internal objects.
• Kept temporal recurrence and diagnostics bounded and deterministic at the current architecture stage.

🧪 Testing

• Verified the Rust workspace test suite successfully.
• Verified unit, integration and temporal test suites included in the workspace test run.
• Verified compile-fail doctests enforcing the execution lifecycle boundary.
• Confirmed that ProposedPlan, ValidatedPlan and ActionPlan remain rejected by the executor at compile time.
• Preserved temporal tests covering recurrence, availability, diagnostics and interval behavior.

⚠️ Known Limitations

• Advanced recurrence behavior beyond the current bounded Temporal Core remains outside the completed milestone where not explicitly implemented.
• Real calendar/provider integrations remain intentionally unimplemented.
• Advanced repair search, learned ranking, preference learning and neural planning remain future milestones.
• Cerebri Lab remains a developer/research interface and is not a production end-user calendar application.
• The current Node integration remains provisional unless explicitly changed by a future milestone.
• Remote GitHub Actions verification is tracked separately from the successful local Rust workspace test run.

🛠️ Development

• Continued development using an AI-assisted workflow with human-defined architecture, documented decisions, automated tests and repository-level verification requirements.
• AI-assisted changes remain subject to the same architecture, safety, testing, documentation and review requirements as other contributions.

📐 Specification History

Architecture and specification revisions are tracked independently from software releases.

🟣 [Specification 0.4] — 2026-09-19

[image: Specification] [image: Baseline]

🔄 Changed

• Frozen Specification 0.4 as the Foundation Architecture Baseline.
• Synchronized the lifecycle diagram and Execution => AuthorizedActionPlan invariant.
• Defined CPIR PolicyContext and PolicySnapshot semantics.
• Defined PlanningScope omitted/empty/list semantics and max_mutations = 0.
• Defined SearchAssessment::COMPLETE.
• Simplified PRESENT_KNOWN to KNOWN and made UNRESOLVED a processing state.
• Defined per-action ExecutionResult semantics and final executor precondition checks.
• Added the Master Specification archive policy.

🗂️ Change Categories

To keep future entries consistent and easy to scan, changes may be grouped using the following categories:

📝 Entry Template