Checkpoint a workspace session

Execution roots (required)

When the host executes commands inside Bash, replace the bash executable shown below with "$BASH" to reuse that shell. This avoids selecting a different Bash from PATH, such as the Windows WSL launcher inside a Git Bash session. In a terminal outside Bash, select the installed Bash explicitly.

Use the exact roots supplied by the host attachment: KernelRoot is the trusted Context OS product containing scripts/contextos.sh; ContextRoot owns tracked identity and lifecycle state; and WorkingRoot is the ordinary application. For an external attachment, require all three exact absolute paths and run:

bash <KernelRoot>/scripts/contextos.sh --context-root <ContextRoot> --working-root <WorkingRoot> <command>

Do not search upward or infer a root from cwd or the skill installation. The kernel must validate the ignored local binding before strict lifecycle work. A missing, moved, stale, linked, nested, or mismatched binding stops the workflow; use the explicit project rebind proposal after a legitimate move. ContextRoot owns all lifecycle writes. WorkingRoot is read-only evidence. The colocated bash scripts/contextos.sh <command> compatibility form remains valid.

Throughout this procedure, resolve every context and local-artifact path beneath ContextRoot. In split mode, spell local paths as absolute <ContextRoot>/... paths and invoke every lifecycle command through the absolute KernelRoot wrapper with both exact role options. In colocated mode, run the relative compatibility commands from the colocated root.

Save continuity with minimal churn through the deterministic lifecycle kernel.

Procedure

1. Identify what was completed, any decisions, and whether a priority or open thread changed. Do not invent progress.
2. Create a reviewed JSON payload under <ContextRoot>/.context-os/inputs/ with progress as one to three factual strings. Make each progress entry one self-contained sentence naming its subject and stating one fact; avoid label-prefixed fragments and multiple facts in one sentence, but keep a status and its qualifiers in the same sentence. Apply the same rule to handoff prose. Include current_markdown only when a priority shifted, a thread opened or closed, or a tracked task completed. When present, it is the complete desired ContextRoot current.md before the kernel advances its date and history. Preserve unrelated content and ordering.

3. Run exactly one matching form:

   split:     bash <KernelRoot>/scripts/contextos.sh --context-root <ContextRoot> --working-root <WorkingRoot> propose update --input <ContextRoot>/.context-os/inputs/<payload.json>
   colocated: bash scripts/contextos.sh propose update --input .context-os/inputs/<payload.json>

   The kernel owns session append behavior, dates, the single Last Updated line, and same-day history. Present every returned diff and the exact proposal digest. The digest binds the exact content but does not authenticate a human approver; rely on the host permission boundary for confirmation.

4. Wait for explicit approval of that exact proposal. Then run:

   split:     bash <KernelRoot>/scripts/contextos.sh --context-root <ContextRoot> --working-root <WorkingRoot> apply <ContextRoot>/<proposal> --confirm <digest> --runtime <active-runtime>
   colocated: bash scripts/contextos.sh apply <proposal> --confirm <digest> --runtime <active-runtime>

   If any target changed after proposal creation, create and review a new proposal. Never bypass stale-write, path-containment, or locking checks.

5. If a durable decision was made, mention that $end can add it to the decision log; do not expand a checkpoint into a full close workflow.
6. Report the receipt path and changed files. Do not edit lifecycle state directly, commit, push, or touch files only to refresh timestamps.