Understand an actual project's code through standard editor AI chat, real execution and the native debugger in VS Code and Cursor. Save an explained code path as learning material, or independently generate a repository-wide DeepWiki site.
| Feature | Experience |
|---|---|
| Live explanation | Ask /codebook in Copilot Chat or Cursor Agent. The AI operates the real application/runtime, pauses actual source, explains in chat and continues. Inspect values in the native debugger. |
| Learning replay / time-travel debugging | Replay the application, the source executing at that time and historical values/stack in the native debugger in sync. Repeatedly step backward/forward and seek after runtime exit. The live chat area becomes a learning summary with a sequence diagram. |
| Independent LLM Wiki / DeepWiki | Reproduce DeepWiki itself through the editor AI's generation skill: full chapters, diagrams, source citations, reader navigation and repository Q&A. Keep local/configurable output, chat/browser updates and source links into your editor. Runtime/debug MCP and learning are independent. |
The owner retired the three selectable UI themes, not these distinct feature screens. Codebook Activity Bar navigation reaches them. The v9 product image is owner-approved after GStack design review. Implementation follows the working loop and the acceptance map, with mandatory visual inspection.
Codebook contributes debug.focusEditorOnBreak: false as the native debugger default, so a breakpoint can select its source and values without moving the keyboard out of the chat. This default applies to native debugging throughout editors where Codebook is enabled. At a stop Codebook did not cause (a step or a continue of yours, a refresh of the debug adapter, or a debug session that is not a Codebook run), Codebook gives the paused file the keyboard once, as the editor would without this default; it does nothing while a recording is open or when you set the setting yourself. Existing explicit User and Workspace preferences take precedence; Codebook writes no settings file. Set debug.focusEditorOnBreak to true in the ordinary editor settings if you prefer the debugger to focus source at a break. Disabling or removing Codebook removes its default contribution.
This is a preview, not a Marketplace or Open VSX release. The delivered version is 0.2.35.0 once the third pull request of Cycle 0049 is merged; until then 0.2.34.0 (PR #116) is the delivered one, and the active cycle Issue says where the delivery stands. Cycle 0049 is a feature cycle: a Vitest test run that the editor chat explained becomes a learning replay, a test replay. Its first pull request holds the loop and its contracts: a test run reads demonstrated once its test passed after every declared stop and its history sealed complete; Save learning replay and Open replay in the status bar save and open it (its test output, the executed source and the native debugger's recorded stops; no application video); the run resource tells the agent the test's result and which explanations the saved learning still lacks; a node-test start's refusals arrive before its first stop with their fix; and the bundled skill 1.0.46 routes a question about a test to this flow. The MCP API is 1.8. Its second pull request shows the recorded test output in the Application pane, updated in place up to the selected moment, and rebuilds the Study pane's test replay section around that moment (Previous stop and Next stop first, the learning summary drawn as a browser replay's with the selected step); its third shows the executed source in one recorded-source tab that the native debugger's frames open, takes the earlier moment off the tab and the debugger before each move, marks the unrecorded time on the slider and bounds Play's wait between events; the native round in both editors follows its merge; the test replay's summary in the Learning summary view is the next feature cycle. What each earlier cycle delivered, with its tests, trials and limits, is in the change history and in that cycle's record, kept under the tag docs-archive-2026-10-20; from Cycle 0048 on, the cycle's Issue holds its tasks and state, and its pull requests the results.
The specification is goal version 10, and the implementation targets external repositories. Historical fixture or coupled-Wiki success is not proof of that destination.
Until final acceptance begins, actual-editor development verification uses the owner-designated nextjs-dashboard checkout. Final acceptance requires all nine designated projects in two stages, both editors and every applicable runtime use case. No Stage 1 or Stage 2 PASS is claimed under goal version 10 or under version 9 before it.
| Question | Source of truth |
|---|---|
| How must an agent build and verify the product? | AGENTS.md |
| What image must an agent open and inspect? | Approved v9 PNG and visual contract |
| What are the features and how do they relate? | PRODUCT_GOAL.md |
| What exactly is saved learning? | Learning replay contract |
| How is Wiki independent, generated and updated? | LLM Wiki contract |
| What must pass before completion? | Final acceptance protocol and the fixed project matrix |
| What is implemented, verified and next? | The active cycle Issue (the open Issue with the label cycle) |
| How does the existing preview work? | Version-qualified installation and usage, change history |
| How do development and review work? | Delivery |
| What is the current design authority? | Design target |
Read AGENTS.md when starting or resuming work; Codex loads it as its project instructions, and so does Claude Code while no CLAUDE.md, .claude/CLAUDE.md or CLAUDE.local.md overrides it. PRODUCT_GOAL.md owns the outcomes, AGENTS.md the way of working, and the active cycle Issue the state.
- Goal Issue #1 remains open until all acceptance conditions and owner acceptance hold.
- Cycle 0049 Issue #107 is the active cycle: a feature cycle that makes a Vitest test run the chat explained a saved, replayable learning replay in both editors, in three pull requests merged in order (the loop and its contracts; the Application pane and the Study section; the recorded source, the debugger and the transitions, with the native round in both editors).
- Cycle 0048 Issue #105 is closed after PR #106: a bug-fix cycle with no increment that closed the 24 defects the adversarial review of Cycle 0047's final candidate found, 5 that an archived test guide carried and the 189 found while it ran, and carried nothing.
- Cycle 0047 Issue #90 is closed after PR #91 (record): a bug-fix cycle with no increment that closed the 53 defects Cycle 0046 left and every defect found while it ran (279 rows, the list); the 24 defects that the adversarial review of its final candidate found are the tasks of Cycle 0048, a bug-fix cycle whose pull request holds only their fixes.
- Cycle 0046 Issue #87 is closed after PR #88 (record): a bug-fix cycle with no increment that closed every defect Cycle 0045 left and every defect found while it ran but row 1066 (1192 rows); row 1066 and the findings its delivery's last review left open are the tasks of Cycle 0047.
- Cycle 0045 Issue #85 is closed after PR #86 (record): the frozen natural
/codebookrequest was submitted three times per host, sixteen causes that stopped it are fixed and the 222 defects Cycle 0044 left are closed (rows); what it leaves is the task list of Cycle 0046, a bug-fix cycle (the list). - Cycle 0044 Issue #83 is closed after PR #84 (record): Update LLM Wiki ends with a result the learner can see on the Wiki page and in the editor, and of the 440 defects earlier cycles left open 439 were closed before the pull request and the last one on it, when the new DOM check job passed (its first run failed for a missing video encoder on the CI runner, and the workflow was fixed) (rows). It is the first cycle under the cycle rule.
- Cycle 0043 Issue #80 is closed after PR #81 (record): a stop the debugger binds on the next line is accepted there instead of ending the run. Work resumed on the owner's direction of 2026-10-03 on a Windows host with WSL (hosts rule).
- Cycle 0042 Issue #78 is closed after PR #79 (record): a pause away from the next declared stop's line that the debugger makes and resumes by itself after a continuation no longer ends a live run.
- Cycle 0041 Issue #76 is closed after PR #77 (record), Cycle 0040 Issue #74 after PR #75 (record), Cycle 0039 Issue #72 after PR #73 (record), Cycle 0038 Issue #70 after PR #71 (record), Cycle 0037 Issue #67 after PR #68, Cycle 0036 Issue #65 after PR #66, Cycle 0035 Issue #63 after PR #64, Cycle 0034 Issue #61 after PR #62, Cycle 0033 Issue #59 after PR #60, Cycle 0032 Issue #56 after PR #58, Cycle 0031 Issue #53 after PR #54, Cycle 0030 Issue #50 after corrective PR #52, and Cycle 0029 Issue #46 after PR #48. Each next cycle Issue is created through
/spec(delivery chain). - The closed cycle records, kept under the tag
docs-archive-2026-10-20, preserve historical results, failed attempts and their exact source/host boundaries.
Advance only the active phase authorized by the owner. After the v9 design review, the owner authorized product implementation; the current state of the active cycle's record holds the current phase and next action. Record actual evidence and update the active cycle's record and its current state before handoff.