Tech Spec

Codex compatibility note:

• Invoke repository skills with $skill-name in Codex; this mirrored copy rewrites legacy Claude /skill-name references.
• Task tracker mandate: BEFORE executing any workflow or skill step, create/update task tracking for all steps and keep it synchronized as progress changes.
• User-question prompts mean to ask the user directly in Codex.
• Ignore Claude-specific mode-switch instructions when they appear.
• Strict execution contract: when a user explicitly invokes a skill, execute that skill protocol as written.
• Subagent authorization: when a skill is user-invoked or AI-detected and its protocol requires subagents, that skill activation authorizes use of the required spawn_agent subagent(s) for that task.
• Do not skip, reorder, or merge protocol steps unless the user explicitly approves the deviation first.
• For workflow skills, execute each listed child-skill step explicitly and report step-by-step evidence.
• If a required step/tool cannot run in this environment, stop and ask the user before adapting.

Codex Project-Reference Loading (No Hooks)

Codex uses static project-reference loading instead of runtime-injected project docs. When coding, planning, debugging, testing, or reviewing, open project docs explicitly using this routing.

Always read:

• docs/project-config.json (project-specific paths, commands, modules, and workflow/test settings)
• docs/project-reference/docs-index-reference.md (routes to the full docs/project-reference/* catalog)
• docs/project-reference/lessons.md (always-on guardrails and anti-patterns)

Missing/stale context route: If docs/project-config.json, the docs index, lessons.md, CLAUDE.md, AGENTS.md, or any task-required reference doc is missing or stale, auto-run $project-init or the narrow setup route ($project-config, $docs-init, $scan-all, $scan --target=<key>, $claude-md-init) before ordinary project-specific work. If Codex mirrors or AGENTS.md are missing/stale, ask the user to run $sync-codex; do not auto-run it.

Situation-based docs:

• Project structure/architecture/tech-stack/deployment/setup (any layer — backend, frontend, or infra): project-structure-reference.md
• Backend/CQRS/API/domain/entity changes: backend-patterns-reference.md, domain-entities-reference.md
• Frontend/UI/styling/design-system: frontend-patterns-reference.md, scss-styling-guide.md, design-system/README.md
• Spec authoring, docs/specs/ pathing, or TC format: feature-spec-reference.md, spec-system-reference.md, spec-principles.md
• Behavior/public-contract changes or spec-test-code sync: workflow-spec-test-code-cycle-reference.md plus the spec docs above
• Derived spec indexes/ERDs/reimplementation guides: spec-system-reference.md and source Feature Specs under docs/specs/
• Integration test implementation/review: integration-test-reference.md
• E2E test implementation/review: e2e-test-reference.md
• Code review/audit work: code-review-rules.md plus domain docs above based on changed files

Do not read all docs blindly. Start from docs-index-reference.md, then open only relevant files for the task.

[BLOCKING] Execute skill steps in declared order. NEVER skip, reorder, or merge steps without explicit user approval. [BLOCKING] Before each step or sub-skill call, update task tracking: set in_progress when step starts, set completed when step ends. [BLOCKING] Every completed/skipped step MUST include brief evidence or explicit skip reason. [BLOCKING] If Task tools are unavailable, create and maintain an equivalent step-by-step plan tracker with the same status transitions.

Quick Summary

Portability: the technical root is read from docs/project-config.json → specRoots.technical.path (declared authorship: "derived", m1Policy: "exempt"). NEVER hardcode a root. {TechRoot}/{Service}/{Component}.md is a pattern — {Service} and {Component} are placeholders resolved from the repo, never literal names.

[IMPORTANT] task tracking — Break ALL work into small tasks BEFORE starting (one task per emitted artifact).

Goal: Generate, on demand, a regenerable single-writer technical view — per-component derived specs (use-case inventory, TC↔test map, cross-service topology) — projected FROM code and test annotations (TestSpec for business TC joins, TechnicalSpec for technical-only joins when present), so an engineer can read a component's technical surface without ever forking a second, hand-maintained source of truth. Code and tests are the source of truth; this skill only projects them.

Summary:

• Purpose: a DERIVED-view generator ONLY — greps handlers/consumers/jobs/producers and test annotations to emit {TechRoot}/{Service}/{Component}.md; it NEVER authors business content. Code + tests stay the source of truth.
• Main steps (run in order): Step 0 Scope Gate — ask the user directly (service/component + mode), BLOCKING before any read; no source to derive from → STOP. Step 1 Derive facts — grep the use-case inventory, the TestSpec/TechnicalSpec joins, the topology. Step 2 Instantiate templates — references/author.md's fixed sections in pinned order. Step 3 Stamp & Write — DERIVED banner + regenerate date, write each artifact immediately (never accumulate in context). Step 4 Verify — no retired artifacts, banner present, no business artifact types, no canonical claims, no secrets.
• Modes: generate (default — regenerate the derived view) · audit (report which views are stale vs code/tests) · sync (report canonical §8 TC ↔ executing test-code drift — references/sync.md).
• Hard prohibition is the load-bearing rule: never emit the retired A-E engineering tree, M## dirs, 00-module-registry.md, 01-domain-erd.md, or 06-reimplementation-guide.md under the technical root — why: an A-E bundle becomes a second source of truth competing with the Feature Spec, and a generator able to recreate it resurrects the retired tree on its next run (this has occurred once already, via rebase).
• Every generated file carries the > DERIVED — regenerate with the tech-spec skill; do NOT hand-edit banner + a regenerate date, anchors each fact back to its source, and makes no canonical claim.
• This skill is M1-EXEMPT (specRoots.technical.m1Policy: "exempt") — its prose MAY name technology. That exemption is the whole reason this tree exists; it is NOT a licence to carry business content (see Hard Prohibitions).

[SCOPE] This skill generates a DERIVED technical view over code + tests under specRoots.technical.path. It MUST NOT emit a per-module A-E engineering bundle (A-domain-model, B-business-rules, C-api-contracts, D-events, E-user-journeys), M## directories, 00-module-registry.md, 01-domain-erd.md, or 06-reimplementation-guide.md — those are not part of the spec model. It MUST NOT author business content: the Feature Spec under specRoots.business.path owns §1–§8, and this skill neither writes nor amends it. Authority: docs/project-reference/spec-system-reference.md, .claude/skills/shared/sdd-artifact-contract.md.

Inputs: the code tree (command/query handlers, event consumers, background jobs, producers, sagas, outbox) and the test tree (TestSpec and TechnicalSpec annotations when present). Code is the technical source of truth — this skill reads it to project a view, never to populate a parallel canonical layer.

Modes:

Tooling:

• npm run tech-spec:generate — regenerate the derived technical views from code/test annotations. Equivalent direct invocation, for projects that copy .claude/ without a package.json: node .claude/skills/tech-spec/scripts/generate-tech-specs.mjs

Mode resolution (do this before any work):

1. Parse the mode from the invocation: explicit [mode=<x>] arg wins; else infer ("regenerate tech specs", "technical spec for {Component}" → generate; "stale", "audit" → audit; "sync tests", "reconcile tests", "reverse sync", "harvest" → sync).
2. If ambiguous, present the detected mode by asking the user directly before proceeding — NEVER auto-start a mutating mode.
3. Read the matching references/ body — it is the single source of truth for that mode's procedure, gates, and output contract. Do not run a mode from memory.

Workflow: $scout (locate the component) → $tech-spec (project the view) → $changes-review → $watzup

The Generator Contract (NON-NEGOTIABLE)

This skill is a generator, not an author. Every clause below is structural — none is a preference a future maintainer may relax for convenience.

C8 — Mechanical detect + route · never judge · never write business content

A generator MUST NEVER apply RIT — or any judgment test — at generation time. Judgment produces data; generators consume data. Canonical formulation: .claude/skills/shared/sdd-artifact-contract.md (beside RIT). Cited, not restated.

Idempotency holds because nothing is re-judged. The generator reads a verdict it did not make and cannot revise. Same source + same verdicts ⇒ same output, every run. A generator that judges is not idempotent — it fails C6 against its own tree, permanently, and the failure reports as hand-edited, which is the wrong cause and undiagnosable.

Two resolutions that are FORBIDDEN, because both look like fixes:

C9 — The harvest detector REPORTS; it never gates

A structural proxy for a semantic property REPORTS; it never blocks. Canonical formulation: .claude/skills/shared/sdd-artifact-contract.md (beside RIT). Cited, not restated.

Harvest detection is a structural signal — an invariant enforced at ≥2 points with no business rule citing it (the countable property references/sync.md step 2 already asks for). It is mechanical, so this skill may perform it. Its output is a candidate list for human or $spec [mode=update] adjudication.

• NEVER an error. NEVER a build gate. NEVER a precondition on regeneration. NEVER a fixture that fails CI.
• The detector is a structural proxy: it infers a semantic property from a correlate, and the rule-citation link it reads is prose, not a key. It has false positives (a covered invariant can present as uncovered) and false negatives (an invariant enforced at one chokepoint is invisible to a ≥2-point counter).
• Why it may not gate: a false positive that blocks a build gets suppressed — and a suppressed detector is a dead detector. A report cannot be suppressed, because it never blocked anything worth suppressing it for.
• A detection changes the report, never the tree — so it cannot break C6.

The boundary — C9 does NOT license softening anything else:

Do not misread C6 as a proxy. C6's rule is "regeneration over unchanged source produces an empty diff" — and the empty diff IS the rule. It executes the property rather than reasoning toward it. Demoting C6 would destroy the only real oracle here. C6 gates at error, and nothing stands behind it to be a proxy for.

Step 0 — Scope Gate (MANDATORY FIRST)

Before reading anything, use ask the user directly. Confirm:

[BLOCKING] Resolve specRoots.technical.path from docs/project-config.json FIRST. If it is absent, STOP — the technical root is not configured and this skill has no destination. NEVER hardcode a root. [BLOCKING] If the target {Service}/{Component} has no derivable source (no handlers, consumers, jobs, or annotated tests), STOP — there is nothing to derive from. NEVER fabricate a component to document.

Step 1 — Derive the Facts (grep, never recall)

Read references/author.md and execute its derivation greps. Extract ONLY mechanically-derivable facts:

1. Use Case Inventory — write ops (N), read ops (M), event-driven (K), background jobs (J), and actor roles, per references/author.md.
2. TC↔test map — the join over existing test annotations (TestSpec for business TC coverage, TechnicalSpec for technical-only coverage when present), generated from the annotations that already exist in code. NEVER hand-move this data.
3. Cross-service topology — producers, consumers, sagas, shared contracts, data ownership (the SYNC:cross-service-check scan below is the procedure).
4. Anchors — every fact carries an abstract [Source: {namespace}/{service}/{id}] anchor.

Scale note: for a service with many components, you MAY spawn parallel reader sub-agents (one per component) that each return the extracted fields above. This is an optimization, not a gate. [BLOCKING] Do NOT interpret, rank, assess business relevance, or judge any derived fact (C8). Count it, anchor it, emit it.

Step 2 — Instantiate the Templates

Per references/author.md: fixed sections, declared order, pinned table sort keys, templated prose over grepped values.

[BLOCKING] A fact that cannot be templated is emitted in a table, never narrated. Free composition is where non-determinism lives, and it breaks C6.

Step 3 — Stamp & Write

• Every generated file opens with the > DERIVED — regenerate with the tech-spec skill; do NOT hand-edit banner + a regenerate date.
• Write each file immediately after instantiating it; do NOT accumulate large outputs in context (C4).

Step 4 — Verify (self-check before completing)

• No retired artifacts emitted — grep your own output paths: zero M[0-9] dirs, zero A-domain-model/B-business-rules/C-api-contracts/D-events/E-user-journeys, zero 00-module-registry/01-domain-erd/06-reimplementation-guide.
• DERIVED banner + regenerate date present on each generated file.
• No business artifact types — zero US-, AC-, BR- identifiers anywhere under the technical root (C2).
• No canonical claims — the derived files never assert they are the source of truth (C3).
• Every anchor resolves — grep the source path; mark [UNVERIFIED] rather than guessing.
• No secrets — zero connection strings, credentials, tokens, internal hostnames, or customer data encountered while reading config/seeders/fixtures.
• Idempotency — re-running over unchanged source produces an empty diff (C6).

Hard Prohibitions (NON-NEGOTIABLE)

This skill produces only the DERIVED technical view. Emitting an A-E engineering tree would create a second source of truth competing with the Feature Spec — and a generator still able to recreate A-E would resurrect the retired tree on its next run, which is an active hazard rather than a theoretical one: the tree has come back once already through a rebase and had to be re-deleted. Therefore this skill MUST NEVER create:

Scope: this prohibition governs the emit set under specRoots.technical.path — the filenames this skill may create. It does not ban writing those names in prose elsewhere (an ADR recording the retirement must be able to name them as history).

If a user explicitly asks for an A-E bundle, explain it is retired and offer the derived view instead. If a user asks this skill to write a business rule or user story, route to $spec — this skill has no authoring path.

Related Skills

What Is $tech-spec?

A derived-view generator over code + tests. The canonical technical knowledge is the code itself, and a technical-only behavior's guard is its test; this skill assembles a regenerable projection (use-case inventory, TC↔test map, topology) so a component's technical surface can be read without a second hand-maintained layer. It does not reverse-engineer code into a parallel canonical bundle — that role was retired with the A-E tree, and this skill exists precisely because a projection cannot rival its own source.

Cross-Service Check — Microservices/event-driven: MANDATORY before concluding investigation, plan, spec, or feature doc. Missing downstream consumer = silent regression.

Boundary	Grep terms
Event producers	Publish, Dispatch, Send, emit, EventBus, outbox, IntegrationEvent
Event consumers	Consumer, EventHandler, Subscribe, @EventListener, inbox
Sagas/orchestration	Saga, ProcessManager, Choreography, Workflow, Orchestrator
Sync service calls	HTTP/gRPC calls to/from other services
Shared contracts	OpenAPI spec, proto, shared DTO — flag breaking changes
Data ownership	Other service reads/writes same table/collection → Shared-DB anti-pattern

Per touchpoint: owner service · message name · consumers · risk (NONE / ADDITIVE / BREAKING).

BLOCKED until: Producers scanned · Consumers scanned · Sagas checked · Contracts reviewed · Breaking-change risk flagged

AI Mistake Prevention — Failure modes to avoid on every task:

Re-read files after context changes. Context compaction, resume, or long-running work can make memory stale; verify current files before acting. Verify generated content against source evidence. AI hallucinates APIs, names, claims, and document facts. Check the relevant source before documenting or referencing. Check downstream references before deleting or renaming. Removing an artifact can stale docs, generated mirrors, configs, and callers; map references first. Trace the full impact chain after edits. Changing a definition can miss derived outputs and consumers. Follow the affected chain before declaring done. Verify ALL affected outputs, not just the first. One green check is not all green checks; validate every output surface the change can affect. Assume existing values are intentional — ask WHY before changing OR flagging one as a defect. Before changing or reporting a constant, limit, flag, cutoff, wording, or pattern, read nearby context and history, the CALLER's ordering, and 2+ sibling call sites of the same convention. A doc stating WHAT without WHY is missing rationale, not proof of a missing guard. Surface ambiguity before acting — don't pick silently. Multiple valid interpretations require an explicit question or stated assumption with risk. Assert the outcome your system owns, not the intermediate state your infrastructure owns. When verifying async work, assert the final business state — never the delivery/retry bookkeeping held in shared infrastructure that any co-running process can write. Such a check passes when run alone and flakes the moment anything else shares that infrastructure. Keep shared guidance role-relevant. Universal guidance must help every receiving skill or agent; code-specific obligations belong only in code-specific protocols.

Critical Thinking Mindset — Apply critical thinking, sequential thinking. Every claim needs traced proof, confidence >80% to act. Anti-hallucination: Never present guess as fact — cite sources for every claim, admit uncertainty freely, self-check output for errors, cross-reference independently, stay skeptical of own confidence — certainty without evidence root of all hallucination.

IMPORTANT MUST ATTENTION microservices/event-driven: scan producers, consumers, sagas, contracts in task scope. Per touchpoint: owner · message · consumers · risk (NONE/ADDITIVE/BREAKING). Missing consumer = silent regression.

MUST ATTENTION apply critical + sequential thinking — every claim needs appropriate traced evidence (file:line for repo/code claims; source URL or artifact section for research, product, content, and docs claims); confidence >80% to act, <60% DO NOT recommend. Anti-hallucination: never present guess as fact, admit uncertainty freely, cross-reference independently, stay skeptical of own confidence.

MUST ATTENTION apply AI mistake prevention — verify generated content against evidence, trace downstream references before deleting or renaming, verify all affected outputs, re-read files after context loss, and surface ambiguity before acting.

Prompt-Enhance Closing Anchors

IMPORTANT MUST ATTENTION follow declared step order for this skill; NEVER skip, reorder, or merge steps without explicit user approval IMPORTANT MUST ATTENTION for every step/sub-skill call: set in_progress before execution, set completed after execution IMPORTANT MUST ATTENTION every skipped step MUST include explicit reason; every completed step MUST include concise evidence IMPORTANT MUST ATTENTION if Task tools unavailable, maintain an equivalent step-by-step plan tracker with synchronized statuses

Parallel Sub-Agent Dispatch — Plan parallelism the moment a task breakdown exists, BEFORE executing it — running provably independent tasks sequentially wastes wall-clock. Applies to every multi-step job: workflow steps, planning, batch updates, investigation, research, scans, reviews, doc sync. Plan execution is metadata-gated, NEVER default-parallel — fan-out follows ONLY what the plan declares (PAR/SEQ tags + per-phase write set); an untagged plan runs sequentially — why: a derived write set cannot see cascade or generated writes.

1. Tag every task PAR or SEQ. PAR = inputs exclude every pending task's output AND write set disjoint from every other PAR. Else SEQ — MUST ATTENTION name the dependency forcing it.
2. Group PAR into waves. No edge between members. Two writers of one file NEVER share a wave. Read-only work (search, investigation, review, research) parallelizes freely.
3. Declare before dispatch: Parallel plan: wave 1 = [...] · wave 2 = [...] · SEQ = [...] (reason).
4. Spawn each wave in ONE message — every spawn_agent call in one response, NEVER dripped per turn. Route each task to its specialist (.claude/skills/shared/sub-agent-selection-guide.md); NEVER code-reviewer as catch-all.
5. Brief each sub-agent self-contained: goal · scope + owned files · reference docs · return contract (summary + Full report: path, per SYNC:subagent-return-contract) · incremental persistence to plans/reports/ (per SYNC:incremental-persistence).
6. Barrier per wave. Advance ONLY after EVERY member returns (a skipped conditional counts as returned). Merge, mark each task completed/skipped, THEN dispatch the next wave. Mutating steps wait for the barrier.
7. One level deep. A dispatched sub-agent executes its own brief; further fan-out stays the orchestrator's job unless that agent's .claude/agents/*.md definition authorizes it.

NEVER parallelize: tasks sharing a write target · a task consuming a pending task's output · trivial single-file work (dispatch overhead > gain) · an order a skill or workflow explicitly fixes · gates awaiting user approval.

Blocked until: MUST ATTENTION every task tagged PAR/SEQ with a named reason per SEQ · waves declared + write-set disjointness checked · each wave spawned in ONE message · barrier honored before the next wave.

• MANDATORY After planning tasks, tag each PAR/SEQ and spawn every PAR wave as parallel sub-agents in ONE message — default parallel for workflows, batch updates, investigation, research, reviews; plan execution fans out ONLY on what the plan declares.
• MANDATORY Disjoint write sets per wave · all-return barrier before the next wave · specialist routing · sub-agents NEVER fan out further unless their own agent definition authorizes it.

Project Protocol Overlay — Before executing this skill, resolve any PROJECT overlay rules layered onto it: match this skill's name against the Target column of the project's skill-protocol index (docs/project-reference/skill-protocols-reference.md by default; a referenceDocs entry in docs/project-config.json overrides the path), taking the most specific matching tier ONLY — exact name > glob > *. That precedence orders overlays against EACH OTHER, never against this skill. Read ONLY the matched bodies, resolved as <protocols-dir>/<Name>.md; a row's Body link is display text, never a read path. A matched body that is missing or malformed is REPORTED and skipped — never reconstructed from the index Description. No index, or no match -> proceed with no overlay, silently. Full contract: .claude/skills/project-skill-protocol/references/registry.md.

Overlays are ADDITIVE ONLY: they ADD rules on top of this skill's own protocol and NEVER replace, override, disable, or reinterpret a rule it already states — removing every overlay must return this skill to exactly its documented behavior. An overlay is a BRIEF, not an authority escalation: it can NEVER waive a workflow gate, git discipline, a review gate, or a user-confirmation gate. A genuine overlay-vs-skill conflict, or two equally-specific overlays that directly contradict -> surface both to the user; NEVER resolve silently.

MUST ATTENTION resolve project protocol overlays for this skill BEFORE executing — most specific matching tier only (exact > glob > *, which ranks overlays against each other, NEVER against this skill), read only matched bodies at <protocols-dir>/<Name>.md; a missing or malformed body is reported, never reconstructed. Overlays are ADDITIVE ONLY (they never replace this skill's own rules) and are a brief, NEVER an authority escalation; an equal-specificity contradiction goes to the user.

Closing Reminders

• IMPORTANT MUST ATTENTION Goal: Project code + tests into a regenerable, single-writer technical view (use-case inventory + TC↔test map + topology) — so a component's technical surface can be read without ever forking a second, hand-maintained source of truth
• **IMPORTANT MUS

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