Spec Merger

Before the final executing → closing transition, delta specs (ADDED/MODIFIED/REMOVED/RENAMED) must be published into the main spec base. changes/<change>/ remains the active workflow source; root specs/ is only the published baseline. Specs that aren't synced become lies. A change already in closing must not be routed to spec-merger.

Execution-State Guard

Before ssf sync or any other write, run ssf state get <change-dir> state. Continue only when the persisted state is exactly executing. If it is closing → STOP: "Closing is terminal. Do not route this change to spec-merger; synchronization belongs before the final executing → closing transition." For any other state, or if the state cannot be read → STOP and route through workflow-start; do not perform side effects.

Pre-Flight Checks

Conflict Detection

Run ssf sync <change-dir>. If conflicts are detected (same requirement modified by multiple changes), present the conflict list to the user for resolution order.

Sync Process

Step 1: Identify Deltas

Each specs/<capability>/spec.md under the change folder contains delta operations under ## ADDED/MODIFIED/REMOVED/RENAMED Requirements.

## Purpose is an optional top-level delta extension. Use it only when creating a canonical main spec. When it is absent or empty, the sync result uses and reports a deterministic default Purpose so legacy delta specs remain usable. A delta Purpose must not overwrite an existing main spec Purpose.

Step 2: Apply by Operation

ADDED: Append the requirement to the published baseline's ## Requirements. Create a canonical main spec if it does not exist.

MODIFIED: Match on ### Requirement: <name> and replace its description and scenarios. Flag if the requirement does not exist in the canonical baseline.

REMOVED: Remove the matched requirement from the published baseline. Flag if it does not exist.

RENAMED: Match the old name and change its header to the new name. Flag if the new name collides with an existing requirement.

Step 3: Conflict Detection

Before executing, detect:

• Same requirement modified by multiple unsynced changes → manual resolution
• RENAMED target collides with existing requirement → manual resolution
• MODIFIED/REMOVED targeting nonexistent requirements → flag

Step 4: Execute Merge

Validate every candidate main spec before writing any target. Apply only changed candidates. An operation that is already reflected in the baseline is an idempotent no-op and must report that it made no write. A missing operation target with a case- or whitespace-only near match is an error, not a no-op. Do NOT delete delta specs — they remain for traceability. The root baseline must contain ## Requirements, never ## ADDED/MODIFIED/REMOVED/RENAMED Requirements headers. Unsafe legacy delta-only baselines that cannot be interpreted are rejected instead of guessed.

Step 5: Report

Output sync report table: Capability, ADDED/MODIFIED/REMOVED/RENAMED counts, Status (✓/⚠). Summary with totals and unresolved conflicts.

Guardrails

• Do not delete delta spec files (historical record)
• Do not auto-resolve conflicts across changes
• Do not merge specs for unverified changes
• Validate every candidate main spec before publication; on validation failure, write no target
• Treat only semantically equivalent, already-applied operations as no-op; near-match requirement names must fail

Post-Sync

1. Report results. If no conflicts → ready to archive. If conflicts → user resolves before archive.
2. Change folder (including deltas) remains for traceability.
3. ssf sync automatically writes a publication receipt to the active change state. Do not manually set spec_merged: that legacy marker is not closing evidence. The closing guard recomputes the delta and published-baseline hashes, so any later edit requires another sync.
4. If the change has no delta sections, no publication receipt is required.

Exception Handling

• Parse failures: Report file and section. Do not attempt partial merges.
• No deltas: If change has no delta sections, report nothing to merge and exit cleanly.
• User interruption: On resume, check for merge conflict markers before proceeding.