Durable Session State

Long swarm-mode sessions outlive their context window. Compaction summarizes history, and summaries lose exactly the things the swarm gates depend on: which diff a reviewer approved, what evidence was recorded, which decisions are settled. Without durable artifacts, a resumed session re-litigates settled decisions or — worse — treats a stale approval as current. Persist state to files as you go; treat the conversation as cache, not storage.

Where artifacts live

• Generic swarm tasks: .claude/session/tasks/<task-slug>/ in the project.
• Issue-tracer work: .agents/issue-traces/<issue-slug>/ (that skill's own schema — 08b-implementation-review.md, 09-final-critic.md — wins for its work).
• Never write task artifacts to the repo root, and never under .swarm/ — that directory is the OpenCode plugin's runtime state, not Claude Code's.
• These artifacts are working state, not deliverables: do not commit them unless the user asks. Before committing, check git status and exclude them explicitly.

What to persist

Keep it to four small files per task; update in place:

1. plan.md — task scope, success criteria, files in scope, what must not break. Update when scope changes; never fork a second plan file.
2. decisions.md — one line per settled decision with a one-line rationale ("chose X over Y because Z"). Settled means: do not reopen without new evidence or a user request.
3. evidence.md — validation commands run and their outcomes (pass/fail plus the load-bearing output lines, not full logs).

4. gates.md — the approval ledger. One entry per reviewer/critic verdict:

   ## <gate> — <APPROVE|NEEDS_REVISION|BLOCKED>
   when: <ISO timestamp or turn marker>
   head: <git rev-parse HEAD>
   diff: <git diff --stat summary>
   items: <blocking items, or none>

When to write

• At phase boundaries (scope settled, plan built, implementation done, each gate verdict received).
• Before ending a turn while background subagents are running.
• Whenever you notice the conversation is long — write ahead of compaction, not after it.

Resume protocol

On resuming (after compaction, a restart, or a handoff), before doing new work:

1. Re-read the task's artifacts. They are authoritative over your memory of the conversation.
2. Do not re-litigate decisions.md entries or redo work evidence.md already proves, absent new evidence or a user request.
3. Check gate staleness: if git rev-parse HEAD or the working-tree diff no longer matches the latest APPROVE entry in gates.md, that approval is invalid — re-run the affected reviewer/critic gate on the current diff.
4. If artifacts and the summarized conversation disagree, trust the artifacts and say so.

Relationship to swarm gates

The swarm-mode contract invalidates any approval issued before the latest edit. The gates.md ledger is what makes that rule checkable instead of vibes: record the HEAD and diff summary at approval time, compare on resume and before final synthesis. If you cannot demonstrate approval-after-last-edit from the ledger, the gate is not satisfied.