Reversible agent task

Reversible Agent Task

Use a proposal-first workflow when direct mutation would make review, rollback, or comparison harder.

Use When

• an agent runner, SET bundle, or planning doc mentions retained output, proposal lifecycle, settlement, or reversible traces;
• the task can be attempted in a worktree, draft branch, sandbox, retained-output folder, or external runner proposal;
• multiple possible implementations should be compared before one is applied;
• the target repo should remain unchanged until a human or supervisor reviews the output.

Lifecycle

1. run: execute the task in a proposal context, such as a worktree, draft branch, sandbox, or retained-output directory.
2. retained_output: keep generated files, diffs, logs, and proof artifacts separate from the target workspace.
3. inspect: review diff scope, verification evidence, assumptions, and expected artifacts.
4. select: mark one retained output as the candidate result.
5. apply: merge or copy the selected proposal into the target workspace only after gates pass.
6. discard: reject the proposal and leave the target workspace unchanged.

Procedure

1. Define the target workspace and the proposal workspace.
2. State the mutation rule: no direct writes to the target workspace until apply.
3. Capture expected artifacts, verification commands, and retained-output path before the run.
4. Run the agent or implementation loop in the proposal context.
5. Inspect the retained output:
   • changed files;
   • generated artifacts;
   • tests or checks run;
   • unresolved assumptions;
   • scope drift.
6. Choose exactly one settlement action: select, apply, or discard.

Output Shape

Include:

• target workspace;
• proposal workspace or retained-output location;
• lifecycle state reached;
• artifacts produced;
• verification evidence;
• settlement action: select, apply, or discard;
• blockers or assumptions.

Guardrails

• Do not present retained output as applied work.
• Do not hide failed proposals; summarize why they were discarded.
• Do not mutate the target workspace during run or inspect.
• Do not use this skill for trivial one-file edits where normal git diff review is enough.
• Keep the proposal mechanism host-agnostic: worktree, branch, sandbox, retained directory, or external runner are all acceptable.

Pair With

• pipeline-readiness-gate for pre/post/ship gate selection.
• assumption-excavation before running high-ambiguity proposals.
• confidence-fragility-review before applying a proposal with public or release claims.
• delivery-baseline-audit before calling applied work complete.
• filesystem-context-discipline when retained outputs, scratchpads, or handoffs need durable file structure.

Provenance

Adapted from proposal lifecycle patterns in reversible agent runtimes such as shepherd-agents/shepherd, narrowed into a host-agnostic ABVX review discipline. This skill does not require Shepherd.