Closes #N (issue to be filed)
Lets canvas / operators see live tool calls + AI thinking instead of
waiting for the high-level activity log to flush. Right now the only
way to "look over an agent's shoulder" is `docker exec ws-XXX cat
/home/agent/.claude/projects/.../<session>.jsonl`, which:
- doesn't work for remote workspaces (Phase 30 / Fly Machines)
- requires shell access on the host
- has no pagination
This PR adds:
1. `BaseAdapter.transcript_lines(since, limit)` — async hook returning
`{runtime, supported, lines, cursor, more, source}`. Default returns
`supported: false` so non-claude-code runtimes pass through gracefully.
2. `ClaudeCodeAdapter.transcript_lines` override — reads the most-
recently-modified `.jsonl` in `~/.claude/projects/<cwd>/`. Resolves
cwd the same way `ClaudeSDKExecutor._resolve_cwd()` does so the
project dir name matches what Claude Code actually writes to. Limit
capped at 1000 to prevent OOM.
3. Workspace HTTP route `GET /transcript` — Starlette handler added
alongside the A2A app. Trusts the internal Docker network (same
model as POST / for A2A); Phase 30 remote-workspace auth is a
follow-up.
4. Platform proxy `GET /workspaces/:id/transcript` — looks up the
workspace's URL, forwards GET, caps response at 1MB. Gated by
existing `WorkspaceAuth` middleware (same as /traces, /memories,
/delegations).
Tests: 6 Python unit tests cover empty dir / pagination / multi-session
/ malformed lines / limit cap, plus 4 Go tests cover 404 / proxy
forwarding / query-string propagation / unreachable-workspace 502.
Verified end-to-end on a live workspace — returns real claude-code
session entries through the platform proxy.
## Follow-ups
- WebSocket variant for live streaming (instead of polling)
- Canvas UI tab "Transcript" between Activity and Traces
- LangGraph / DeepAgents / OpenClaw transcript adapters
- Phase 30 remote-workspace auth on /transcript
853734aa4e