checkpoint

name	checkpoint
version	1.0.0
description	Save session state for context compaction survival. Called automatically during plan and implement-plan workflows at natural break points — after each phase, before subagent calls, and at context pressure.

Checkpoint: save session state

When to checkpoint

• After completing each phase of an implementation plan
• Before spawning subagents (saves state before delegation)
• After receiving subagent results
• When context is nearing capacity (long conversation, many tool calls)
• Before any multi-edit batch

What to save

Write a checkpoint file to session memory at /memories/session/checkpoint-<datetime>.md.

Each checkpoint captures:

• Step context: current plan step/phase, plan file path, frontmatter state
• Work done: 2-3 sentence summary of what was accomplished this session
• Next steps: what remains (list items from plan)
• Cross-file state: file paths being edited, pending decisions, key search results

How to save

Memory tool availability: If the memory tool is not in the available tool list, call activate_vs_code_interaction with no arguments first — it is a one-shot call that permanently unlocks VS Code interaction tools.

1. Run date -u +%Y-%m-%dT%H%M%S for ISO timestamp.
2. Construct path /memories/session/checkpoint-<datetime>.md.
3. Call memory create with path /memories/session/checkpoint-<datetime>.md and file_text containing the checkpoint content.

How to restore

The continue.prompt.md, verify-plan.prompt.md, and verify-implementation.prompt.md workflows each find and load the latest checkpoint when resuming after interruption or context compaction. A checkpoint provides enough context to continue without replaying full history.

Integration

The plan.prompt.md and implement-plan.prompt.md prompts invoke this skill at natural break points. When those prompts invoke skill: "checkpoint", follow the save workflow above. Do not ask for confirmation.