v2.5.1

[2.5.1] - 2026-03-28

Fixed

• KB retrieval failures silently swallowed: except Exception: pass around Bedrock KB retrieval in query_kb/handler.py hid all errors. Now surfaces ClientError with specific handling for ThrottlingException (user-friendly retry message) vs other errors.
• Unsafe os.environ[] access across Lambdas: Replaced all bracket-style env var access with os.environ.get() plus explicit ValueError for required vars in appsync_resolvers, queue_processor, and dlq_replay.
• Unbounded S3 reads risk OOM: read_s3_text() and read_s3_binary() now check ContentLength before reading, with a configurable max_size_bytes (default 50MB).
• DynamoDB partition key wrong in troubleshooting docs: Query example used "PK" instead of "Configuration".
• --project-name flag references across docs: All documentation now uses --stack-name (the actual CLI flag).
• Caching documentation contradictions: Three docs claimed "no caching" while ConfigurationManager uses request-scoped caching. All now consistent.
• 12 drift findings in DEVELOPMENT.md: Corrected nonexistent scripts, wrong filenames, stale descriptions, and missing Lambda functions.

Changed

• AppSync resolvers split into domain modules: appsync_resolvers/index.py reduced from 1,400+ lines to 179-line dispatcher. Business logic extracted into resolvers/shared.py, documents.py, images.py, scrape.py, metadata.py, chat.py.
• query_kb dual-import pattern consolidated: _compat.py now centralizes all cross-module imports. Consumer modules use a single try/except ImportError block each (was 5-6 per file). type: ignore comments reduced from ~25 to ~16.
• extract_kb_scalar deduplicated: Moved from inline implementations in both search_kb and query_kb to shared ragstack_common.kb_filters module with unit tests.
• S3 URI parsing consolidated: 16 inline replace("s3://", "").split(...) patterns replaced with parse_s3_uri() from ragstack_common.storage.
• Exception handling narrowed: Bare except Exception blocks replaced with specific types (ClientError, ValueError, KeyError, TypeError) across query_kb and appsync_resolvers. One documented safety-net catch-all retained per Lambda.
• combine_pages boto3 clients moved to module level: Lazy-init singletons for connection reuse across warm Lambda invocations.

Added

• Request-scoped config caching: ConfigurationManager.get_effective_config() caches results within a single Lambda invocation. clear_cache() called at handler entry points.
• Frontend type safety wrappers: graphql.ts with gqlQuery() and gqlSubscribe() replaces all as unknown as string and as any casts in UI hooks.
• no-console ESLint rule: 66 console.log/error/warn calls removed from frontend source. Rule enforced for all .ts/.tsx files.
• Coverage enforcement: --cov-fail-under=60 in CI pytest (current coverage: 65%).
• Pre-commit hooks: .pre-commit-config.yaml with ruff check and format hooks.
• Missing doc links: IMAGE_UPLOAD.md, API_REFERENCE.md, and MIGRATION.md added to README documentation index.
• Repository structure updated: CLAUDE.md and DEVELOPMENT.md reflect resolver split, 32 Lambda functions, and current architecture.

Removed

• Unused min_per_slice parameter: Removed from merge_slices_with_guaranteed_minimum() along with vulture whitelist entry.

Security

• npm audit vulnerabilities resolved: Zero vulnerabilities across root, src/ui, and src/ragstack-chat.
• pygments CVE-2026-4539: No fix version available (transitive dep from pytest). Documented as known exception.