Shared transcript-core

Per-provider store locations, record parsing, and structural filtering for Claude Code, Codex, and Cursor start in src/transcript/core/runtimes.ts. Cursor's reliability contract adds two canonical modules beside it:

• src/transcript/core/cursor-frames.ts streams physical JSONL frames, preserving closed, blank, malformed, partial, repaired, and replaced boundaries plus file identity and prefix-verification evidence.
• src/transcript/core/cursor-analysis.ts assembles turns and separates prefix-stable content availability from terminal lifecycle outcomes.

Rather than cross-skill runtime imports, each consumer ships committed generated copies under its own scripts/lib/. pnpm run build materializes those copies, so each skill remains dependency-free and install-free while tracing back to canonical TypeScript.

Consumers

Current consumers of the shared transcript-core:

• session-observer — ships runtimes.mjs, cursor-frames.mjs, and cursor-analysis.mjs, plus its generated digest, locate, observe, state, and watch pipeline.
• export-session-transcript — ships runtimes.mjs, cursor-frames.mjs, and cursor-analysis.mjs.

The lower-level Cursor normalizer remains terminal-only for Export Session Transcript compatibility. Session Observer explicitly requests the content-first observation projection. Session Observer Collaboration explicitly requests confirmed-completion from the observer-generated modules; its control, hook, completion, and lease files remain authored JavaScript.

Schema and position semantics

The public digest is a discriminated union:

• Schema v1 keeps existing non-Cursor behavior and zero-based-jsonl-record-index accounting.
• Cursor schema v2 uses zero-based-jsonl-frame-index. fromIndex is inclusive, nextIndex is the first unconsumed safe frame, and toIndex is nextIndex - 1 or null. An entry's recordIndex is its delivery frame; sourceFrameIndex retains the original content frame.

Consumers dispatch on both fields. They never infer an index base from the runtime name or convert a persisted record position into a frame position. Cursor observation may expose stable content with lifecycle pending, while the completion projection remains terminal-success-only.

Editing the source

Edit the applicable canonical module under src/transcript/core/ or src/transcript/session-observer/, then run pnpm run build to update every declared committed output.

The drift guard makes skipping the rebuild a hard error: pnpm run build:check regenerates expected output in check mode and fails on any divergence, and the same guard runs in pnpm test through tests/tooling/generated-output-sync.test.ts. Editing the canonical module without rebuilding the generated output breaks the suite.

Compatibility wrapper

pnpm run sync:transcript-core remains as a compatibility command for existing habits and automation. It delegates to scripts/build-generated.mjs, and node scripts/sync-transcript-core.mjs --check delegates to scripts/build-generated.mjs --check.