Release 0.14.0 (2026-03-24)

Fixed

Specification Documents

• docs/features/event-system.md — Fixed severity levels from warning/critical to warn/fatal, aligning with PROTOCOL_SPEC §10.2
• docs/features/core-executor.md — Fixed Identity description: removed incorrect permissions field, corrected to id, type, roles, attrs per PROTOCOL_SPEC §5.7
• docs/features/core-executor.md — Added missing ApprovalPendingError to Approval Gate description per PROTOCOL_SPEC §7.4
• docs/features/middleware-system.md — Added retry.py to Key Files table (was described in Components but missing from file list)
• docs/features/observability.md — Added concrete metric names (apcore_module_calls_total, apcore_module_errors_total, apcore_module_duration_seconds) to convenience method documentation

Protocol Specification

• Fixed duplicate ### 10.5 section numbering — renumbered Sensitive Data Redaction to §10.6, Sampling Strategy to §10.7, Span Naming Convention to §10.8
• Fixed ### 8.1.1 misnumbered under §9.1 — corrected to §9.1.1
• Fixed ### 10.8.x misnumbered under §11.8 — corrected to §11.8.1–§11.8.4
• Fixed middleware priority model contradiction between §11.2 (explicit 0-1000) and §12 (registration order) — §12 now aligns with §11.2
• Fixed on_error examples in README.md and concepts.md — changed raise error to correct return-based contract (return None / return dict)
• Updated "Last Updated" date to 2026-03-24

Scope Document

• Added Approval System (§7) and Event System to "Core Protocol Includes" list in SCOPE.md

README

• Added AI-Perceivable brand definition block to README header
• Added "Perceived → Understood → Executed" progression table to "Why AI-Perceivable?" section

Ecosystem

§5.13 Display Overlay (specified in v0.13.0) is now implemented across the official adapter stack:

Package	Version	What was implemented
apcore-toolkit	0.4.0	DisplayResolver — §5.13 resolve priority chain, MCP alias sanitization/64-char limit, CLI alias validation, suggested_alias fallback, binding_path file/directory loading
apcore-cli	0.3.0	CLI command routing from metadata["display"]["cli"]["alias"]; descriptor cache; JSON output reads display overlay
apcore-mcp	0.11.0	MCP tool name and description from metadata["display"]["mcp"]; guidance appended to tool description
apcore-a2a	0.3.0	A2A skill id/description/tags from metadata["display"]["a2a"]; removed dead _build_extensions()
fastapi-apcore	0.4.0	binding_path parameter on create_cli() / create_mcp_server(); DeprecationWarning for simplify_ids=True

• §5.14 Convention Module Discovery — new optional protocol capability for zero-decorator module registration via commands/ directory convention.

Release 0.13.0 (2026-03-12)

Added

Protocol Specification

• Caching annotations (§4.4) — cacheable, cache_ttl, cache_key_fields annotation fields for AI-aware caching decisions
• Pagination annotations (§4.4) — paginated, pagination_style (cursor/offset/page) for paginated result handling
• AI Metadata Conventions (§4.6) — 13 standardized x- metadata keys across 4 categories: Intent, Planning, Performance/Cost, Trust/Verification
• sunset_date (§5.2) — ISO 8601 date field for module deprecation lifecycle
• on_suspend() / on_resume() (§5.6, §12.7.3) — Optional lifecycle hooks for state preservation during hot-reload
• Hot Reload with State Migration (§12.7.3) — New section with algorithm, constraints, and Python example
• Ecosystem documentation — Added apcore-mcp, apcore-a2a, and apcore-testing to README and SCOPE

Schema

• module-meta.schema.json — Added streaming, cacheable, cache_ttl, cache_key_fields, paginated, pagination_style, sunset_date definitions

Changed

• Rebranded from "universal module development framework" to "AI-Perceivable module standard" with three-tier messaging (slogan/subtitle/full definition)
• SCOPE.md — Expanded boundary decisions from 17 to 26 rows; updated requirements wording from "The framework" to "Implementations"
• Section renumbering — §12.7.3–12.7.8 renumbered after hot-reload insertion
• Lifecycle table (§12.7.1) — Reordered to show on_resume after on_load, with note clarifying old/new instance distinction

Fixed

• Cross-references — Fixed 10+ stale §11.7.x and §12.7.x references across architecture, registry-api, algorithms, and context-object docs
• Metadata key consistency — Aligned x-max-latency-ms description between README and PROTOCOL_SPEC

Release 0.12.0 (2026-03-10)

Added

Protocol Specification (v1.5.0-draft)

• Error catalog expanded (§8.2) — Added MODULE_DISABLED, EXECUTION_CANCELLED, RELOAD_FAILED error codes with retryability classification and error hierarchy entries
• UsageCollector formalized (§10.4) — Added usage tracking specification for UsageCollector and UsageMiddleware backing system.usage.* modules

Conformance

• Shared conformance fixtures (conformance/fixtures/) — 7 JSON fixture files for cross-language testing: pattern_matching, specificity, normalize_id, call_chain, error_codes, version_negotiation, acl_evaluation

Changed

Protocol Specification

• Context.child() naming (§12.7.2) — Standardized derive() → child() to match SDK implementations
• Forward-declared errors resolved — GENERAL_NOT_IMPLEMENTED and DEPENDENCY_NOT_FOUND now fully implemented in both SDKs

Documentation

• Cross-reference links — Added links between API docs and feature docs (executor-api.md, context-object.md)
• Conformance known deviations — Updated status of error code implementations

Fixed

• CHANGELOG count corrections — System modules 10→9, APCore client methods 19→17
• Phantom entry removed — TypeScript batchProcessing annotation (never implemented)

Release 0.11.0 (2026-03-09)

Added

Documentation — New Files

• APCore Client API (docs/api/client-api.md) — Full API reference for the unified APCore client covering 17 public methods: call, call_async, stream, validate, module, register, discover, list_modules, describe, use, use_before, use_after, remove, on, off, disable, enable, plus events/registry/executor properties and global apcore.* entry points
• Event System (docs/features/event-system.md) — EventEmitter, ApCoreEvent, EventSubscriber protocol, WebhookSubscriber (retry strategy), A2ASubscriber (auth modes), subscriber type factory registry, event types table, and YAML configuration reference
• System Modules (docs/features/system-modules.md) — Complete reference for 9 built-in system.* modules with input/output schemas: system.health.summary, system.health.module, system.manifest.module, system.manifest.full, system.usage.summary, system.usage.module, system.control.update_config, system.control.reload_module, system.control.toggle_feature; plus register_sys_modules() setup guide and YAML configuration

Documentation — Updated Files

• Observability features — ErrorHistory, UsageCollector, PlatformNotifyMiddleware documented
• Middleware guide — Built-in RetryMiddleware + RetryConfig reference added
• Schema system — SchemaStrategy and ExportProfile enums documented

Changed

Documentation — Updated Files

• docs/getting-started.md — Added §8 Global Entry Points (16 apcore.* module-level functions) and §9 System Modules quick start with health/usage/manifest examples
• docs/api/executor-api.md — validate() return type updated from ValidationResult to PreflightResult with 6-check breakdown and requires_approval flag; call()/call_async()/stream() signatures updated with version_hint parameter; added ModuleDisabledError, ModuleTimeoutError, ReloadFailedError, FeatureNotImplementedError, DependencyNotFoundError to error types; timeout section rewritten for dual-timeout model with cooperative cancellation (CancelToken + 5s grace period)
• docs/api/registry-api.md — Added disable()/enable() module toggle, safe_unregister() with cooperative drain (Algorithm A21), acquire() context manager, is_draining(), describe() for AI/LLM tool discovery, negotiate_version() (Algorithm A14)
• docs/features/observability.md — Added three subsystems: ErrorHistory (ring buffer with deduplication, ErrorEntry dataclass), UsageCollector (hourly bucketed storage, trend computation, UsageMiddleware), PlatformNotifyMiddleware (threshold-based alerting with hysteresis)
• docs/guides/middleware.md — Replaced hand-written RetryMiddleware example with built-in RetryMiddleware + RetryConfig reference (exponential/fixed backoff, jitter, retryable-only); added §5.5–5.7 cross-references for ErrorHistoryMiddleware, UsageMiddleware, PlatformNotifyMiddleware
• docs/features/schema-system.md — Added SchemaStrategy enum (yaml_first, native_first, yaml_only) and ExportProfile enum (mcp, openai, anthropic, generic)
• docs/features/core-executor.md — Added dual-timeout model (global deadline + per-module), cooperative cancellation with CancelToken, deep merge for streaming (depth cap 32), error propagation via propagate_error() (Algorithm A11), PreflightResult validation
• docs/README.md — Added client-api.md, event-system.md, system-modules.md to directory tree, API reference table, feature specifications table, and concept index

Release 0.10.0 (2026-03-07)

Added

Protocol Specification

• IDConverter implementation note (§12.2) — SDKs MAY implement as utility function instead of class
• MiddlewareManager split-method pattern (§12.2) — SDKs MAY use execute_before/execute_after/execute_on_error instead of unified run_chain()
• Module.stream() optional method (§5.6) — Documented stream() as optional method in Module interface for streaming support

Error Hierarchy

• DependencyNotFoundError — New error class for DEPENDENCY_NOT_FOUND code (previously forward-declared)
• FeatureNotImplementedError (Python) / NotImplementedError (TypeScript) — New error class for GENERAL_NOT_IMPLEMENTED code (previously forward-declared)

Changed

• Executor pipeline docs — All references updated from "10-step" to "11-step" pipeline across README.md, docs/features/core-executor.md, docs/api/executor-api.md
• Context logger property — Upgraded from SHOULD to MUST in docs/api/context-object.md (both SDKs already provide it)
• docs/api/module-interface.md — Added optional stream() method documentation
• **docs/getting-started.md** — Rewritten to recommend APCore` unified client as primary approach

Release 0.9.0 (2026-03-06)

Added

Protocol Specification

• Executor.validate() preflight (§12.2) — [SHOULD] non-destructive preflight check through Steps 1–6 without invoking module code or middleware; new PreflightResult / PreflightCheckResult types with duck-type ValidationResult compatibility
• §12.8 Executor.validate() Cross-Language Implementation Guide — error handling mapping, type mapping for Python/TypeScript/Go/Rust/Java/C/C++, schema library requirements, naming conventions
• Preflight Tests added to §12.4 Consistency Test Suite (7 test cases)
• Context optional extension fields — cancel_token, services, redacted_inputs with serialization rules (§5.7)
• New error codes — CONFIG_NOT_FOUND, CONFIG_INVALID, SCHEMA_CIRCULAR_REF, BINDING_FILE_INVALID, MIDDLEWARE_CHAIN_ERROR, VERSION_INCOMPATIBLE, ERROR_CODE_COLLISION, CIRCULAR_DEPENDENCY, DEPENDENCY_NOT_FOUND (§8)
• New error classes — BindingFileInvalidError, MiddlewareChainError, VersionIncompatibleError, ErrorCodeCollisionError added to error hierarchy
• AI error guidance fields — retryable, ai_guidance, user_fixable, suggestions for improved LLM agent error handling
• AI intent metadata keys (§4.6) — x-when-to-use, x-when-not-to-use, x-common-mistakes, x-workflow-hints conventions for LLM agents
• TypeScript and C/C++ added to §12.6 Language-Specific Implementation Notes

Changed

• PROTOCOL_SPEC.md — bumped to v1.4.0-draft
• Executor pipeline renumbered from 10 steps (with Step 4.5) to clean 11 steps — Approval Gate is now Step 5, subsequent steps shifted +1
• §7.4, §7.9, streaming protocol references updated to match new 11-step numbering
• Executor.validate() preflight added to §12.3 cross-language requirements table
• Section cross-references fixed — §11.7→§12.7, §10.3→§11.3, §9.7→§10.7, §7→§8 (error code references)
• Retryability table updated with new error codes; MIDDLEWARE_CHAIN_ERROR removed from forward-declared list
• docs/api/context-object.md — added optional extension fields documentation
• docs/api/executor-api.md — added AI error guidance fields and new error types
• docs/concepts.md — expanded AI collaboration and cognitive interface concepts
• SCOPE.md — updated to reflect new features

Release 0.8.0 (2026-03-03)

Added

• AI Collaboration Lifecycle documentation: Integrated description, metadata, requires_approval, and ai_guidance into a unified narrative (Discovery, Strategy, Governance, Recovery).
• New "Cognitive Interface" concept in README.md and docs/concepts.md.
• Intent-oriented design tips in docs/guides/creating-modules.md.
• Comprehensive multi-language "Getting Started" guide covering both Python and TypeScript side-by-side
• Multi-language support (side-by-side examples) in "Creating Modules" guide
• Unified documentation links across all implementation READMEs (apcore-python, apcore-typescript)
• TypeScript examples for Registry, Executor, and Module definition in core documentation

Changed

• README.md — Updated Quick Start with multi-language tabs and links to the new Getting Started guide

Release 0.7.0 (2026-03-01)

Added

Protocol Specification

• Approval System (§7) — new section in PROTOCOL_SPEC.md defining the ApprovalHandler protocol, ApprovalRequest/ApprovalResult data types, Executor Step 4.5 integration, error types (APPROVAL_DENIED, APPROVAL_TIMEOUT, APPROVAL_PENDING), built-in handlers, protocol bridge handlers, phased implementation (Phase A sync, Phase B async), and conformance levels

Feature Documentation

• docs/features/approval-system.md — full specification of the Approval System feature

Changed

• PROTOCOL_SPEC.md — bumped to v1.3.0-draft; added "Recommended AI Intent Metadata Keys" (§4.6) outlining x-when-to-use, x-when-not-to-use, x-common-mistakes, and x-workflow-hints conventions for LLM agents; updated requires_approval annotation description to reference runtime enforcement; added approval error codes and error hierarchy; renumbered §7–§13 → §8–§14
• docs/api/executor-api.md — added approval_handler constructor parameter, ApprovalDeniedError/ApprovalTimeoutError to error types, Step 4.5 to execution flow and state machine
• docs/api/module-interface.md — updated requires_approval annotation description to reference Approval System and runtime enforcement
• docs/features/core-executor.md — added Step 4.5 (Approval Gate) to the execution pipeline
• docs/README.md — added Approval System to feature specifications table, directory tree, and concept index

Release 0.6.0 (2026-02-23)

Added

Protocol Specification

• Streaming execution protocol — new section in PROTOCOL_SPEC.md defining streaming execution model for long-running or real-time module outputs
• Module ID constraints & naming conventions — formal rules for module identifiers added to the protocol spec
• SDK export requirements — specified required exports for conformant SDK implementations
• Module interface improvements — refined module interface contracts with streaming semantics

Feature Documentation

• docs/features/acl-system.md — full specification of the Access Control List system
• docs/features/core-executor.md — detailed documentation of the execution pipeline
• docs/features/decorator-bindings.md — guide on the @module decorator and binding mechanics
• docs/features/middleware-system.md — composable middleware pipeline specification
• docs/features/observability.md — tracing, metrics, and structured logging documentation
• docs/features/registry-system.md — module registry and discovery system documentation
• docs/features/schema-system.md — schema-driven module input/output validation documentation

CI/CD & Site

• GitHub Actions workflow (.github/workflows/deploy-docs.yml) for automated documentation deployment
• MkDocs configuration (mkdocs.yml) for the documentation site

Changed

• README — enhanced with unified SDK explanation, TypeScript SDK implementation examples, and updated architecture overview
• SCOPE.md — updated to reflect current project scope and feature set
• docs/concepts.md — rewritten with unified SDK explanation for multi-language context
• docs/architecture.md — updated to align with protocol spec changes
• docs/api/ — updated context-object.md, executor-api.md, module-interface.md, and registry-api.md with version-aligned content
• docs/spec/conformance.md — revised conformance requirements to match 0.2.0 protocol spec
• docs/guides/adapter-development.md — updated adapter development guide
• mkdocs.yml — navigation structure updated to include new feature pages

Removed

• ROADMAP.md — removed; roadmap references updated across documentation
• docs/guides/creating-modules-translated.md — removed translated guide from navigation

Release 0.5.0 (2026-02-22)

Added

Protocol Specification

• Level 2 Conformance (Phase 1) — Extension system, Async Task Management, and W3C Trace Context support added to protocol requirements
• Extension System (§12.2) — Unified extension point framework for pluggable components (discoverers, middleware, ACL, exporters)
• Async Task Management (§12.7.3) — Standardized lifecycle for background tasks (Pending, Running, Completed, Failed, Cancelled)
• Trace Context (§12.7.4) — W3C Trace Context (traceparent) support for distributed tracing propagation
• Async Middleware Protocol — Requirements for non-blocking middleware dispatch