| name | session-sync |
| description | Mid-session checkpoint. Captures decisions, open threads, and key artifacts without ending the session. Activate when the user says "sync" or "checkpoint", or when context pressure makes a save worthwhile. |
| compatibility | Requires agent-memory MCP server with memory_checkpoint |
| trigger | {"event":"session-checkpoint","priority":50} |
| source | user-stated |
| origin_session | manual |
| created | "2026-03-16T00:00:00.000Z" |
| last_verified | "2026-03-16T00:00:00.000Z" |
| trust | high |
Session Sync (Mid-Session Checkpoint)
Load this skill on-demand only — when a checkpoint is needed and you're uncertain about the protocol. For quick reference, core/governance/session-checklists.md § "Mid-session sync" has the compact version.
When to use this skill
Activate when:
- The user says "sync", "checkpoint", "save progress", or similar.
- A long session has produced significant decisions or context that would be costly to lose.
- The agent judges that enough has happened to warrant a checkpoint (use judgment — don't checkpoint after trivial exchanges).
For lightweight in-progress saves, use memory_checkpoint instead. This skill is the heavier checkpoint path: it writes checkpoint.md, stages broader session state, and ends with a commit.
Steps
1. Summarize progress so far
Write a brief checkpoint note capturing:
- Decisions made this session (with reasoning if non-obvious).
- Open threads — questions raised but not yet resolved.
- Key artifacts — files created, modified, or discussed.
2. Persist the checkpoint
If write access is available:
- Prefer local agent-memory MCP write tools when they can perform the checkpoint write cleanly; otherwise use direct file writes.
- Create or update the current session's chat folder (
core/memory/activity/YYYY/MM/DD/chat-NNN/).
- Write a
checkpoint.md file in the chat folder with the summary above. If multiple syncs happen in one session, append to the same file with timestamps.
- Stage any pending knowledge or identity updates that were discussed and approved.
- Commit with message:
[chat] Mid-session checkpoint — <brief description>.
If read-only:
- Present the checkpoint summary to the user so they can save it.
3. Confirm to the user
Briefly confirm what was captured. One or two sentences — not a full recap.
Quality criteria
- The checkpoint should be useful to a future agent (or the same agent after context loss) as a recovery point.
- Decisions are captured with enough context to understand why, not just what.
- The checkpoint is concise — aim for 10–20 lines, not a full session transcript.
Anti-patterns
- Don't checkpoint trivially. A two-message exchange about a typo doesn't need a sync.
- Don't duplicate the final session summary. Checkpoints are mid-session snapshots, not premature wrap-ups.
- Don't block the user. The sync should take seconds, not interrupt the flow of work.
Context-pressure flush
This is an automatic variant of the checkpoint protocol above. It triggers without a user request when context loss is imminent.
When to trigger
- The agent estimates it has consumed >75% of its effective context window.
- The platform signals that compaction, summarization, or context truncation is imminent.
- The agent detects that it can no longer recall details from earlier in the session that it previously had access to.
What to do
- Execute Steps 1–2 of the manual checkpoint protocol above (summarize progress, persist
checkpoint.md).
- If the chat folder does not yet exist, create it before writing.
- If a
checkpoint.md already exists from an earlier sync, append a new timestamped section rather than overwriting.
- Commit with message:
[chat] Context-pressure flush — <brief description>.
- If read-only, present the checkpoint summary to the user immediately.
What not to do
- Do not attempt a full session wrap-up — this is a checkpoint, not an ending.
- Do not interrupt the user's active request to announce the flush. Complete the current response first, then flush.
- Do not flush if the session has produced no decisions, artifacts, or meaningful context since the last checkpoint.
Advisory note
Most current platforms do not expose context-usage metrics to agents. This protocol documents the intended behavior so that agents which can detect context pressure know what to do, and platforms that add this capability have a target protocol to trigger. See agent-bootstrap.toml § [compaction_flush] for the machine-readable configuration.