skill-nix-implementation

# Nix Implementation Skill Thin wrapper that delegates Nix configuration implementation to `nix-implementation-agent` subagent. ## Trigger Conditions This skill activates when: - Task type is "nix" - /implement command targets a Nix task - NixOS modules, Home Manager configs, or flake changes need to be created using Nix ## Execution Flow ### Stage 1: Input Validation Validate task_number exists, task_type is "nix", and an implementation plan is present. ### Stage 2 + Stage 3: Preflight Status Update and Postflight Marker Source `skill-base.sh` once, then follow `@.claude/context/patterns/skill-preflight-flow.md` in full for Stage 2 (preflight status update) and Stage 3 (marker creation): ```bash source .claude/scripts/skill-base.sh padded_num=$(printf "%03d" "$task_number") skill_name="skill-nix-implementation" operation="implement" ``` **Intentional behavior fix**: this skill previously wrote no `.postflight-pending` marker at all — zero premature-termination protection. This import gives it one. ### Stage 4a: Memory Retrieval and Literature Detection **Skip memory retrieval if**: `clean_flag` is true (from `--clean`). ```bash if [ "$clean_flag" != "true" ]; then memory_context=$(bash .claude/scripts/memory-retrieve.sh "$description" "$task_type" "" 2>/dev/null) || memory_context="" fi ``` Follow `@.claude/context/patterns/lit-stage4a-flow.md` in full to resolve `--lit` and set `lit_context`, exactly as `skill-implementer` does. This skill supplies the shared block's preconditions: `lit_flag`, `description`, `orchestrator_mode` (default `"false"` when unset). ### Stage 4: Prepare Delegation Context Domain-specific context for the nix-implementation-agent: - Nix style guide from `.claude/extensions/nix/context/` - MCP-NixOS for package/option validation (when available) - Verification: `nix flake check`, `nixos-rebuild build --flake .#hostname` ```json { "session_id": "sess_{timestamp}_{random}", "delegation_depth": 1, "delegation_path": ["orchestrator", "implement", "skill-nix-implementation"], "timeout": 7200, "task_context": { "task_number": N, "task_name": "{project_name}", "description": "{description}", "task_type": "nix" }, "plan_path": "specs/{NNN}_{SLUG}/plans/MM_{short-slug}.md", "metadata_file_path": "specs/{NNN}_{SLUG}/.return-meta.json" } ``` If `memory_context` and/or `lit_context` from Stage 4a are non-empty, include them in the prompt (memory context first, then literature briefing), after the delegation context and before task-specific instructions. Do NOT inject an empty block for either. ### Stage 5: Invoke Subagent Use Agent tool with subagent_type: "nix-implementation-agent". ### Stage 5b: Self-Execution Fallback Follow `@.claude/context/patterns/skill-self-execution-fallback.md` in full. This skill's success status value for that block's write obligation is `"implemented"`. ## Postflight (ALWAYS EXECUTE) The following stages MUST execute after work is complete, whether the work was done by a subagent or inline (Stage 5b). Do NOT skip these stages for any reason. ### Stage 6: Parse Subagent Return Read the metadata file from `specs/{N}_{SLUG}/.return-meta.json`. ```bash metadata_file="specs/${padded_num}_${project_name}/.return-meta.json" if [ -f "$metadata_file" ] && jq empty "$metadata_file" 2>/dev/null; then status=$(jq -r '.status' "$metadata_file") artifact_path=$(jq -r '.artifacts[0].path // ""' "$metadata_file") artifact_type=$(jq -r '.artifacts[0].type // ""' "$metadata_file") artifact_summary=$(jq -r '.artifacts[0].summary // ""' "$metadata_file") memory_candidates=$(jq -c '.memory_candidates // []' "$metadata_file") # Schema: .claude/context/formats/return-metadata-file.md completion_summary=$(jq -r '.completion_data.completion_summary // ""' "$metadata_file") roadmap_items=$(jq -c '.completion_data.roadmap_items // []' "$metadata_file") else echo "Error: Invalid or missing metadata file" status="failed" fi ``` ### Stage 7, 7a, 8, 8a, 9: Postflight Status, Memory Candidates, Artifact Linking, Notify, Cleanup Follow `@.claude/context/patterns/skill-postflight-flow.md` in full: ```bash field_name='**Summary**' next_field='**Description**' ``` **Not covered by the shared block**: `completion_summary`/`roadmap_items` propagation via `skill_propagate_completion_summary`, preserved from before this conversion (already routed through `skill-base.sh`, which is now sourced once at Stage 2 + Stage 3 above rather than re-sourced here): ```bash if [ "$status" = "implemented" ] || [ "$status" = "completed" ]; then # Literal "nix" (deliberate): this skill's Trigger Conditions hardcode a single task_type. skill_propagate_completion_summary "$task_number" "$completion_summary" "$roadmap_items" "nix" fi ``` ## Error Handling ### Input Validation Errors Return immediately if task not found. ### Metadata File Missing Keep status as "implementing", report error. ### Subagent Returns Partial/Failed Do not attempt to continue, complete, or "fill in" the subagent's work. Report the status and let the user re-run `/implement` to resume. ### Git Commit Failure Non-blocking: Log failure but continue. ## MUST NOT (Postflight Boundary) After the agent returns, this skill MUST NOT: 1. **Edit .nix files** - All Nix config work is done by agent 2. **Run nix flake check** - Verification is done by agent 3. **Analyze or grep source** - Analysis is agent work 4. **Write summary/reports** - Artifact creation is agent work > **PROHIBITION**: If the subagent returned partial or failed status, the lead skill MUST NOT attempt to continue, complete, or "fill in" the subagent's work. Report the partial/failed status and let the user re-run `/implement` to resume. The postflight phase is LIMITED TO: - Reading agent metadata file - Updating state.json via jq - Updating TODO.md status marker via Edit - Linking artifacts in state.json - Git commit - Cleanup of temp/marker files Reference: @.claude/context/standards/postflight-tool-restrictions.md ## Return Format Brief text summary (NOT JSON).