comic-panel-prompt-builder — the Deterministic Bake Compiler (搬运工原則)

The last authoring step before a pixel ever gets baked. Given ONE upstream-approved panel_spec and its status: locked blueprint, this skill COMPILES — it does not brainstorm — the exact message comic-director (Phase 2/3) will hand to the agent mcp__codex__codex sidecar bake (Codex's native image tool), plus the locked identity-ref list. It is the comic twin of the framework's shot-prompt-builder: a pure Layer-3 transform with no Codex call in the happy path — it only emits a prompt_bundle; the spiral engine submits it. Everything the generation backend ever sees passes through here, so this is where the 搬运工原則 is enforced at emit time: the bake backend (Codex's native image-generation tool; the underlying image model is not pinned or attested by this repo) owns optics; ART_BIBLE.md owns style; no camera / lens / lighting / "8K hyperrealistic cinematic" padding leaks into the bake, and no bubble text gets baked unless the panel is explicitly text_mode: "baked". The author (storyboard/blueprint layers) decides what; this skill decides nothing — it transcribes a locked spec into a backend-legal string and FAILS (it never papers over) when the spec is malformed.

  panel_spec (status:locked) ─▶ ① RESOLVE  — load panel_spec + its blueprint + ART_BIBLE style_prefix
        + blueprint (status:locked)    enforce 4 prerequisites (node_type, blueprint status:locked, REAL refs, style_prefix resolves)
                              ▼
                        ② COMPOSE  — fixed-section condition_string (order is load-bearing, do NOT refactor)
                              ▼   style_prefix + [BAKED DIALOGUE only if text_mode==baked] + SCENE + FIXED ELEMENTS
                              ▼   + ALLOWED CHANGE vs prior panel + FORBIDDEN + SCREEN-TEXT WHITELIST(expected_literals)
                              ▼
                        ②·5 INJECT (retry only) — active failure_mode positive-invariants to the FRONT
                              ▼
                        ③ VALIDATE  — banned-vocab + length + no-baked-bubbles + real-refs on the COMPOSED string
                              ▼          (the hard gate — ANY hit = fail-closed, push the fix UPSTREAM)
                              ▼
                        ④ EMIT  — write the prompt_bundle node; route html_bubbles[] to the JSON viewer ONLY
                              ▼
                   pass? ─ no ─▶ exit 4 (banned/length) | exit 7 (failure_mode trigger still fires) | exit 3 (prereq)
                              │ yes
                              ▼
                        ⑤ stdout one-line JSON {prompt_bundle_id, panel_id, source_blueprint_id}

Role

You are a fail-closed transcriber, not an author. You take a panel_spec that an upstream layer already gate-approved and its blueprint that the cross-layer gate already flipped to status: locked, and you produce the single exact composed_prompt (style_prefix + a fixed-section condition string) + the locked identity-ref paths that the spiral engine will bake — together with the deterministic proof (a clean banned_vocab_scan) that the message is backend-legal. You never invent a scene element, a number, a cast member, or a style adjective; you never silently fix a malformed spec (you FAIL and point upstream); and you never call Codex on the happy path (a Codex call only ever appears as a reported upstream bug). The cross-model judgement of the baked pixels is not yours — that lives downstream in comic-director's panel_gate; keeping you deterministic is what stops the executor from self-acquitting.

Node — what this skill reads / writes (schemas/node_schema.json)

• Reads panel_spec (node prefix panel:) — payload fields used: source_storyboard_id, page_id, panel_id, sequence_index, page_type, world, asset_ids[], text_mode, expected_literals[], content_blueprint, bubbles[], side_narration, motifs. The panel_spec must be its layer's gate-approved output (status: locked), not a draft.
• Reads the upstream blueprint (node prefix blueprint:, found via the panel's content_blueprint) — payload fields used (the schema's 9 blueprint required fields, verbatim from validate_wiki.py PAYLOAD_REQUIRED): source_panel_id, content_svg, expected_literals[], safe_zones[], html_bubbles[], crop, negative_space_policy, generator_script, file_sha256. Refuse unless the blueprint is status: locked — that is the schema signal that the cross-layer gate signed off (the gate's ⑥ FLIP writes status → locked on advance; comic-blueprint-author emits blueprints at status: locked). The blueprint node has NO review_status field (only the asset node does, and "approved" is not even a legal status enum value) — never gate on review_status here. html_bubbles[] is the JSON viewer-overlay payload — it is routed to the viewer, NEVER concatenated into the bake string.
• Writes one prompt_bundle (node prefix prompt:, node_id a lowercase [a-z0-9_-]+ slug of the panel_id) — payload required by the schema (the 6 prompt_bundle PAYLOAD_REQUIRED fields, verbatim): source_panel_id, source_blueprint_id, style_prefix, composed_prompt, banned_vocab_scan, identity_ref_paths. Status canon: author draft/pending → under_review → locked on a clean validate (or rejected). Write LEGAL edges (every type ∈ validate_wiki.py EDGE_TYPES): derived_from (prompt_bundle → panel_spec) and uses_blueprint (prompt_bundle → blueprint). On retry, the failure_mode trace uses a legal derived_from edge (prompt_bundle → failure_mode, with evidence.consulted_failure_mode + the --reason text — no match score; scoring is planned, not shipped); if a trigger still fires after repair, a legal failure_of edge (failure_mode → prompt_bundle — failure_of points failure_mode → target, matching the gate + the script, trigger in evidence). There is NO generated_from / consulted_failure_mode / violates_failure_mode edge type in EDGE_TYPES — those would fail the release gate. Emit node IDs only to stdout — the orchestrator re-reads the node file from disk (no filename guessing).

Two engine contracts to compile to (fail-closed)

These are the same two contracts comic-author authors to — this skill is where they are enforced at emit time, on the resolved spec, before any credit is spent:

1. Every panel needs a content_svg. On the wiki node this is blueprint.payload.content_svg (top-level on the blueprint payload — NOT nested under any condition. key; the condition.content_svg prefix exists ONLY in the runtime comic.json the engine reads). The blueprint's content_svg is the content authority + the bake's layout reference. If it is null / missing / not on disk (or its file_sha256 mismatches) → refuse (exit 3). A scene-only panel still has a layout blueprint SVG; there is no such thing as a panel with no content_svg.
2. A baked figure-panel must declare non-empty, ascii-tokenizable expected_literals. If text_mode == "baked" and the blueprint carries a figure but expected_literals is empty → refuse (exit 3). Those literals become the SCREEN-TEXT WHITELIST block (below) and are exactly what panel_gate's blind token-diff later verifies. A scene panel with no audited numbers must be text_mode: "html" (dialogue is an HTML overlay, no baked-literal contract).

Procedure (numbered — an agent can execute this step by step)

The shipped entrypoint (do NOT hand-roll the validator):

python3 skills/comic-panel-prompt-builder/scripts/build_prompt.py <project_dir> <panel_id|panel:slug> \
    [--retry --reason "<text>"]

scripts/build_prompt.py IS this procedure made executable — it reads the panel_spec + blueprint nodes from <project_dir>/wiki/nodes/, resolves the identity lock + refs, composes the fixed-section message, and calls the single canonical scripts/_validate.py (which owns MAX_MESSAGE_CHARS = 4000, the ~80-pattern BANNED_VOCAB, no_baked_bubbles, real_refs — imported, never duplicated). It writes the trace files wiki/prompt_build/<panel_slug>/{_resolved.json,_meta.json,_validation.json} and, on a clean validate, the prompt_bundle node + its legal edges. --retry REQUIRES --reason (exit 2 otherwise) — a retry must name the active failure it is repairing. Run python3 scripts/_validate.py --composed <f> --text-mode <m> --bubbles ... --refs ... standalone for a quick re-check of an already-composed message.

0. Phase −1 · parse + scaffold. Parse $2 (the panel_id or panel:slug node_id); make wiki/prompt_build/<panel_slug>/. --retry without --reason → exit 2. The emitted node_id is prompt:<lowercase-slug-of-panel_id> (the schema node_id pattern is [a-z0-9_-]+; the display panel_id may carry case). Never guess output filenames.
1. Phase 0 · resolve + prerequisites (refuse to proceed unless ALL hold). Load into one _resolved.json: the panel_spec node; its blueprint node (via panel_spec.payload.content_blueprint); and the style_prefix from ART_BIBLE.md (the world-keyed STYLE_PREFIX[<world>]: line — §0 register + §0.5 two-world palette). Enforce:
   • (a) node_type == "panel_spec" and status == "locked" — else exit 2 (input missing/malformed).
   • (b) the upstream blueprint.status == "locked" — the schema signal that the cross-layer gate signed off (the gate's ⑥ FLIP writes status → locked). The blueprint node has no review_status field; gating on review_status == "approved" is unreachable (not even a legal status value) → never do it. Optionally also assert the legal decision node / decides edge for this blueprint exists as gate proof. Else exit 3.
   • (c) every ref is a REAL locked asset path, not a placeholder: blueprint.payload.content_svg exists on disk (and file_sha256 matches), and each identity ref — resolved by following panel_spec.payload.asset_ids[] to its identity-sheet asset node (the asset must be status: locked, and publishes a real .png via its ref_requirements) — is a real .png (NOT pending:*, NOT null where one is required). A null ref is allowed ONLY as the documented "use project canonical" fallback; an unresolved pending:* → exit 3.
   • (d) the style_prefix resolves and is sane: ≤ 200 chars (hard), ≤ 32 words (warn). Else exit 3. Also resolve asset names (scene/prop/identity asset_ids[] → display names) for the whitelist/reviewer context only — names go in the whitelist, raw IDs never go in the prompt.
2. Phase 1 · compose the condition string DETERMINISTICALLY in this EXACT load-bearing layout (order is load-bearing — it empirically drives baked-text fidelity; do NOT refactor headings or order without an A/B test). Front = strongest conditioning weight.
   • STYLE PREFIX — from ART_BIBLE.md: tone + two-world palette + texture, world-keyed by panel_spec.world (e.g. warm / seam / dark-cyber / starfield). NO camera/lens/lighting/quality vocab.
   • [BAKED DIALOGUE] — only if text_mode == "baked" lift the panel's bubbles[] text into the prompt (so the image model draws legible balloons). If text_mode == "html" (or code): SKIP this block entirely — the bubbles are the viewer's job (see Phase 4). This is the single switch that decides baked-vs-overlay text.
   • SCENE COMPOSITION NARRATIVE — the scene staging authority is the blueprint.payload.content_svg layout (the content blueprint already lays out the scene) summarized with the panel's panel_spec.payload.side_narration. There is NO condition.scene / condition.characters / chibi_action on the panel_spec node — those keys live ONLY in the runtime comic.json (do not read them off the node). The world's warm/cold contrast is by design, not drift.
   • "FIXED ELEMENTS (must NOT change):" — the identity lock, obtained by following panel_spec.payload.asset_ids[] to each identity-sheet asset node and reading its asset.payload.identity_lock (the canonical-cast hex/beard/silhouette lock — there is NO identity_desc field on the panel_spec node; the node-model identity authority is the asset's identity_lock) + the locked props the motif ledger pins for this panel.
   • "ALLOWED CHANGE (vs the prior panel):" — from the panel's motifs delta (the comic reinterpretation of "ALLOWED MOTION": what may legitimately differ from the previous panel).
   • "FORBIDDEN (must NOT happen):" — the FIXED baseline ["no new character entering frame", "no off-model drift", "no scene/world recolor"] + any panel-specific must_not_add.
   • "SCREEN-TEXT WHITELIST (exact characters to preserve):" — the expected_literals[] from the blueprint (e.g. ["REJECT","37","T-16:05"]) + any baked-in signage/label names. Even when HTML owns the bubbles, baked-in figure text (chips, stamps, code) still needs char-exact preservation — this whitelist is the upstream of panel_gate's literal diff. Write _meta.json (character/element counts) for the trace.
3. Phase 1·5 · failure_mode positive-invariant injection (retry only — the spiral active-memory hook). This is what the SHIPPED build_prompt.py does — mirror it exactly, do not hand-roll a richer version. On --retry, collect ALL ACTIVE failure_mode nodes (payload.active == true) project-wide — there is NO layer or panel scoping in the shipped code. Sort them by payload.severity DESC (default 3 — severity ONLY, no recency term), take the top 10, and for each mode whose encoding_style == "positive_invariant" inject its repair_pattern UNCONDITIONALLY (no semantic matching against the composed string) — non-positive_invariant modes are skipped here (negatives like "no missing ears" make diffusion fixate on the negated concept). The injected patterns form one "POSITIVE INVARIANTS (must be present in every panel, highest priority):" block at the FRONT of the message. Record the consult as a legal derived_from edge (prompt_bundle → the consulted failure_mode) with evidence.consulted_failure_mode: true + the --reason text (there is no consulted_failure_mode edge type). This is exactly the --reason a retry must name. (ASPIRATIONAL — planned, NOT yet implemented; do not describe as current behavior: scoping by the schema's layer field (∈ {prompt_pattern, visual_transition, global} — the field is layer, there is no target_layer in the schema), recency*severity ranking (recency = 1.0/age_days), a semantic_signature weighted-Jaccard match (0.35*assets + 0.25*cterms + 0.20*kw + 0.20*frags, threshold 0.55), and a match score on the edge. The shipped injector is the severity-top-10 unconditional inject above.)
4. Phase 1·6 · trigger re-scan (retry only). Re-scan the FULL composed message against the trigger_patterns of EVERY active failure_mode (not just injected ones). In the shipped script, trigger matching gates ONLY the exit-7 path: if a trigger of a non-positive_invariant mode still matches, it persists the bundle as status: "rejected" FIRST (so the edge endpoint resolves), writes a legal failure_of edge (failure_mode → prompt_bundle — failure_of points failure_mode → target, the trigger in evidence; there is no violates_failure_mode edge type) and exits 7 (a regenerate signal to the orchestrator). A matched positive_invariant mode never exit-7s and there is NO append-in-place repair branch — its repair_pattern was already injected in Phase 1·5 iff it made the severity top-10.
5. Phase 2 · VALIDATE = the hard gate (runs on the FULL composed message; this is the rubric). Delegate to scripts/_validate.py (the single source): passes_all = length_ok AND no_banned_vocab AND no_baked_bubbles AND real_refs_ok. ANY failure → preserve _validation.json, set the panel's review_gates.storyboard_json_gate = "fail", and exit 4 — see the EXACT gate below. Do NOT silently add quotes / fix the spec — a malformed spec FAILS validation so the fix is pushed back to the authoring layer.
6. Phase 3 · emit. Write the prompt_bundle node (payload = the schema's 6 required fields exactly: {source_panel_id, source_blueprint_id, style_prefix, composed_prompt, banned_vocab_scan, identity_ref_paths}); set its status locked. Write the LEGAL edges (every type ∈ EDGE_TYPES): derived_from (prompt_bundle → panel_spec) and uses_blueprint (prompt_bundle → blueprint) — NOT generated_from (illegal, fails the release gate). Route html_bubbles[] to the JSON viewer overlay only — they are NOT in composed_prompt. Append a timeline entry to wiki/log.md.
7. Phase 4 · stdout. Emit one-line JSON {"prompt_bundle_id":"prompt:...","panel_id":"...", "source_blueprint_id":"blueprint:..."} — the canonical orchestrator input. Set panel_spec.review_gates.storyboard_json_gate = "pass".

The EXACT gate (deterministic fail-closed — dimensions + thresholds + veto)

This is a transform, so there is NO cross-model / scored gate here (that lives downstream in comic-director's panel_gate). The gate is a deterministic contract/banned-vocab validator on the COMPOSED message — ported verbatim from shot-prompt-builder / segment-intent-builder. Each dimension is binary; ANY hit is a hard fail (no single-vote averaging — this is detect-only).

• length_ok — len(composed_prompt) ≤ MAX_MESSAGE_CHARS = 4000 (~600 words, the empirical backend tolerance). Over cap → fail.
• no_banned_vocab — the 搬运工 v2 validator: ~80 case-insensitive, word-boundary patterns the backend's own agents own. Veto = any single hit fails the whole message. The list below is the human-readable map; the single source of truth is scripts/_validate.py's BANNED_VOCAB (imported by build_prompt.py, so the list never forks). Categories:
  • Quality padding: \b8K\b, \b4K\b, hyperrealistic, photorealistic, ultra-realistic, cinematic, professional, award-winning, masterpiece, high/best quality, highly detailed, intricate details, trending on artstation.
  • Camera: the camera, camera moves/pans/tilts/zooms/tracks/pushes/pulls/cranes, wide/close-up/medium/long/establishing/POV shot, over-the-shoulder, dolly, tilt, pan, crane, drone, aerial, orbital, whip-pan, tracking shot, push-in, pull out, zoom, rack focus, focus pull, jib, steadicam, handheld.
  • Lens: \d{2,3}mm, f/\d, bokeh, depth of field, shallow DOF, DOF, lens, wide-angle, telephoto, anamorphic, lens flare.
  • Lighting: bare lighting, rim/key/fill light, three-point lighting, golden hour, blue hour, studio lighting, soft/hard light, low-key, volumetric, god rays, chiaroscuro.
  • Engine/brand: Unreal Engine, Octane, V-Ray, Blender, Midjourney, Stable Diffusion, Sora, Runway, Pika.
  • Clichés: epic, breathtaking, stunning, gorgeous, mesmerizing, otherworldly, surreal masterpiece.
• no_baked_bubbles (comic-specific veto) — if text_mode != "baked" and any of the panel's html_bubbles[] / bubbles[] quoted dialogue text appears in composed_prompt → fail. HTML owns the bubbles; baking them is the exact drift this gate exists to catch. (When text_mode == "baked" the dialogue is allowed in the BAKED DIALOGUE block by design — this veto fires only for html/code panels.)
• real_refs_ok (single-source ref veto) — identity_ref_paths[] must be REAL locked .png paths, and the ref set is exact: no silent concatenation of extra identity IDs, no pending:*, no raw asset_id strings smuggled into the prose. (Single-source discipline — the ref-count linchpin; concatenating refs silently is forbidden.)

Exit-code contract (= the verdict surface; scripts/build_prompt.py returns these EXACT numeric codes): 0 validated + emitted + gate pass · 2 input missing / malformed CLI (--retry w/o --reason; panel_spec not node_type panel_spec or not status: locked) · 3 upstream prereq unmet (blueprint not status: locked / ref not real / content_svg missing / expected_literals missing on a baked figure-panel / style_prefix bad / failure_mode query failed) · 4 banned-vocab | length | baked-bubble | ref fail (gate → fail, _validation.json preserved) · 7 Phase 1·6 regenerate (a non-positive_invariant mode's trigger_pattern still matches after repair; the bundle is persisted status: "rejected" and a legal failure_of edge written).

Worked example

The reference movie's per-panel condition blocks — ../../examples/comic_m3_audit/comic.json — are the compiled-artifact (comic.json runtime) OUTPUT shape this skill produces (the spiral engine inlines exactly these condition.* keys). They are NOT the node fields this skill reads — those are the flat panel_spec / blueprint / asset node payloads (the condition. prefix exists only in comic.json). Copy these output patterns, but source each from its node field as noted: