Deleting a pipeline step

Deleting a Pipeline Step — Removal Workflow

<overview> Removes a named step from an existing pipeline. Performs gap analysis to identify predecessor/successor disconnections, stages all file removals and topology mutations for audit, and enforces a mandatory human approval gate before any irreversible deletion occurs. </overview> <glossary> <term name="Gap Analysis">The process of identifying predecessor/successor disconnections caused by a step removal.</term> <term name="Through-gap">A condition where a deleted step sat between two active steps, requiring direct reconnection.</term> <term name="Blocking-gap">A condition where a deleted step was the sole source of required inputs for a successor.</term> </glossary>

Workflow Phases

<protocol> ### PHASE 0: PIPELINE & STEP SELECTION - Resolve scope registries and identify the target pipeline and step. - Display the current `topology.json` as a graph showing all dependency chains.

PHASE 1: GAP ANALYSIS

• Analyze the impact of removal on predecessors and successors.
• <HARD-GATE>If a Blocking-gap is found (no alternative input source), STOP. The user must provide an alternative source or cancel the deletion.</HARD-GATE>

PHASE 2: MUTATION DESIGN (REWIRE)

• For through-gaps or entry-gaps, present a rewire plan to the user (e.g., "Wire A directly to C").
• Dispatch pipeline-architect in STEP-DELETE mode to stage all changes.
• <invariant>All mutations (file removals and topology updates) MUST be staged in edit-{ts}/. NEVER delete directly from production paths during design.</invariant>
• Architect completion manifest gate: After the architect returns, read the STEP-DELETE completion manifest. It MUST cover every file the architect was tasked with touching and use only edited, copied-unchanged, or deleted.
  • <HARD-GATE>If any expected markdown artifact (*.md) is listed as copied-unchanged, STOP before Phase 3. Emit a blocking error naming the file and explain that unchanged markdown in STEP-DELETE staging indicates an architect partial exit.</HARD-GATE>
  • <HARD-GATE>If any expected file is missing from the manifest, STOP before Phase 3. The staging set is incomplete and cannot be audited as a coherent delta.</HARD-GATE>
• Staged markdown modification guard: Independently diff every staged *.md file against its production original before Phase 3. If the staged file has a production source and is byte-identical to that source, STOP before Phase 3 with a blocking error naming both paths. This guard is independent of the manifest and catches partial exits even when the manifest is wrong or missing detail.
• Pre-audit residual-reference scan: Prefer the Phase 3 delta auditor as the authoritative gate. If a manual grep is run as an additional pre-audit smoke check, it MUST explicitly include markdown files (for example, --include="*.md") so .md artifacts cannot be silently skipped.

PHASE 3: DELTA AUDIT

• Dispatch pipeline-auditor in DELTA mode on the staged topology, entry skill, and neighbor steps.
• <HARD-GATE>SEV-0 or SEV-1 findings block deletion. A fragmented pipeline is a critical failure. Re-audit until the delta is clear.</HARD-GATE>

PHASE 4: HUMAN APPROVAL

• Present a "Deletion Manifest" showing exactly which files will be removed and which edges will be rewired.
• <HARD-GATE>Wait for explicit APPROVE. On CANCEL, discard all staged changes and do NOT delete artifacts.</HARD-GATE>

PHASE 5: ATOMIC PROMOTION

• Execute file removals (agents/skills) and write updated topology.json and tasks.md.
• Update the registry.json to reflect the removal.
• Version Stamp: Update plugin_version in topology.json and the registry entry to the current superpipelines version. </protocol>

<invariants> - NEVER assume a step is "unused" without verifying all `depends_on` entries in the topology graph. - ALWAYS perform atomic promotion from a staging area to ensure rollback capability. - NEVER delete a step that creates an unresolvable blocking-gap in the orchestration. - ALWAYS update `plugin_version` in `topology.json` and the registry entry to the current superpipelines version when promoting changes. </invariants>

Red Flags — STOP

• "The pipeline will work without rewiring — it's obvious." → STOP. Obvious assumptions are the leading source of silent runtime failures.
• "I'll skip the human gate; deletion is a simple task." → STOP. Deletion is irreversible; the human gate is the final recovery point.
• "I'll delete the files first, then update the topology." → STOP. This results in a broken pipeline if the topology update fails.

Rationalization Table

<rationalization_table>

Excuse	Reality
"The step is terminal, why audit?"	Removing a terminal step can still break final status reporting or cleanup logic.
"Rewiring is over-engineering."	A broken dependency chain blocks every subsequent pipeline run. Rewiring is essential maintenance.
"I can recover from git if I'm wrong."	Relying on git recovery for basic workflow errors indicates a failure of the safety protocol.
</rationalization_table>

Reference Files

• sk-pipeline-paths/SKILL.md — Path resolution.
• sk-pipeline-state/SKILL.md — Run state tracking.
• adding-a-pipeline-step/SKILL.md — Insertion workflow.
• updating-a-pipeline-step/SKILL.md — Modification workflow.