/epic-delta-loop

Epic Delta Loop

Use this command when new findings during implementation require scope, priority, or acceptance-criteria changes inside an active epic.

Never start from scratch. Extend the existing epic with a controlled delta loop.

Inputs

<delta_input> #$ARGUMENTS </delta_input>

Required:

• parent epic plan path (docs/plans/*-plan.md)
• delta request (new requirement, discovered risk, dependency change, or acceptance update)
• normalize unqualified agent IDs from compound-engineering.local.md to compound-engineering-core:<agent-id> before invocation

If one is missing, ask for it.

Workflow

1. Load parent context

Read:

• parent plan
• parent execution tracker
• latest review evidence files for that epic
• parent plan revision (latest commit SHA + plan hash)

2. Classify delta

Classify delta scope:

• Minor: no acceptance criteria or architecture change
• Material: acceptance criteria, architecture, dependency, risk, or rollout change

Minor deltas can be logged directly in tracker decisions section. Material deltas must run full nested loop below.

3. Material delta nested loop (required for material deltas)

1. Create delta plan file:
   • docs/plans/deltas/YYYY-MM-DD-<epic-slug>-delta-<topic>.md
2. Run teammate plan-review agents on the delta.
3. Validate codex_mcp_server availability. Ignore legacy codex_gate_agent config if present; direct invocation from the current Claude agent is canonical.
4. Run Codex Extra High external review on the delta directly from the current Claude agent through codex_mcp_server.
   • pin to delta revision (commit SHA + delta hash)
   • do not spawn a separate Codex-only Claude sub-agent unless the user explicitly requests that override
5. Ask PM only unresolved decision questions.
6. Update delta plan and repeat until all blockers are cleared.

4. Delta approval criteria

Delta is approved only when:

• PM approves priority/scope change
• teammate plan-review gate passes
• Codex Extra High delta gate passes

5. Merge back to parent artifacts

After delta approval:

1. Update parent plan with delta decisions and acceptance criteria changes.
2. Update parent execution tracker with:
   • delta summary
   • new tasks
   • changed risks
3. Add delta entry in docs/knowledge/plans-index.md notes or linked evidence.
4. Archive closed delta files under docs/plans/deltas/archive/ when fully implemented.
5. If parent plan revision changes materially after merge, rerun relevant plan gate checks.

6. Boundary rule

If delta introduces a new independently shippable workstream, create a new epic plan instead of forcing it into the current epic.

7. Output

Return:

• delta classification (minor/material)
• delta plan path (if material)
• gate evidence paths
• parent plan/tracker files updated
• next implementation step