feat: Claude Code Monitor — lanes, pipelines and a merged workspace

Internal SmartGift build of a Claude Code monitoring dashboard. Lanes: a durable unit of parallel agent work, one per working directory, tracked across session restarts. Managed lanes are git worktrees the dashboard provisions and can reset or remove behind a three-check destroy guard and a counted preflight; adopted lanes are directories you already own and are never destroyable. Pipelines: a lane moves through pipeline stages. A stage the agent declares with evidence renders green; a stage inferred from the tool-event stream renders dashed amber and never counts as done. Detection is forward-only within a 30-minute window, and never writes the declared stage. Workspace: one page at /run with a lane grid, the selected lane's pipeline, and a full Claude console behind a disclosure.
2026-07-29 17:07:45 +07:00
commit 57dc91585d
783 changed files with 221743 additions and 0 deletions
@@ -0,0 +1,55 @@
+---
+description: >
+  Trace error propagation through a multi-agent session by agent depth — where
+  failures originated, the depth at which they appeared, and how they cascaded
+  up to parent agents — using the Agent Monitor workflow intelligence API and
+  the session event stream. Use when a multi-agent run failed and you need to
+  find the origin and blast radius of the failure.
+---
+
+# Error Propagation
+
+Trace where a multi-agent session's failures started and how far they spread.
+
+## Input
+
+The user provides: **$ARGUMENTS**
+
+A session ID. If empty, fetch `GET /api/sessions?limit=1`, but prefer the most recent session whose `status` is `error` or `abandoned`; state which one you picked.
+
+## Data Sources
+
+| Endpoint | Returns |
+|----------|---------|
+| `GET /api/workflows/{sessionId}` | The `errorPropagation` dataset: failures grouped by agent depth, with originating depth and cascade paths to parents |
+| `GET /api/events?session_id={sessionId}` | The event stream — corroborate with `APIError`, `SubagentStop`, and failing `PostToolUse` events (`event_type`, `tool_name`, `summary`, `timestamp`) |
+
+## Report Sections
+
+### 1. Failure Summary
+From `errorPropagation`: total errors, the depth where the first error originated, and how many distinct agents were affected.
+`Origin depth: d · Errors: N · Agents affected: M`
+
+### 2. Errors by Depth
+| Depth | Errors originated | Errors inherited from children | Net failing agents |
+|-------|-------------------|--------------------------------|--------------------|
+Show whether failures concentrate deep in the tree (leaf subagents) or shallow (orchestrator).
+
+### 3. Cascade Paths
+For each originating failure, the path it propagated along:
+`debugger (depth 2, tool failure) → code-review (depth 1, marked error) → root (depth 0, aborted)`
+Tie each step to a concrete event from `/api/events` (event_type + tool_name + timestamp) where available.
+
+### 4. Error Taxonomy
+Break errors down by type from the event stream: `APIError` vs failing tool calls vs `SubagentStop` with error status. Note the most frequent tool involved in failures.
+
+### 5. Containment Assessment
+Whether failures were contained at the depth where they originated or leaked to parents. Name any parent that aborted solely because a child failed — a candidate for better error handling / isolation.
+
+## Output
+
+- Markdown tables for the depth breakdown; a fenced list for cascade paths.
+- Timestamps for the first and last error.
+- Cite only errors present in `errorPropagation` and the event stream; never invent failures or causes.
+- If the session has no errors, say so plainly and stop.
+- If the dashboard is unreachable, tell the user to start it with `npm start` from the repo root.