Flux 3 Prompt Doctor

FLUX 3 Prompt Doctor

Resolve the decisions that change routing, payload, or production method before a brief becomes a prompt. Ask only blocking questions; use documented defaults or label assumptions for everything else. Preserve the user's product names, exact copy, source roles, and hard constraints verbatim. This skill does not write the final prompt or call the API.

Route by what must survive

Every request names its mode and carries the matching media field:

| Requirement | Route | | --- | --- | | Generate the whole clip from words | mode: "t2v", no media | | An image must appear on screen exactly as shot | mode: "i2v", keyframes | | Bridge an exact opening and closing frame | mode: "i2v", two keyframes | | Pass through visual waypoints | mode: "i2v", keyframes as a storyboard | | Continue from an existing ending | mode: "v2v", start_video | | Render an approved draft without replanning | mode: "draft_enhance", draft_cache |

Two questions separate the image routes: must these exact pixels be on screen (keyframes)? Can the source simply be described (then attach nothing)? There is no field that carries a subject's identity without putting the source on screen; a brief that needs one either opens each shot from a keyframe containing the subject, or is a REVISE.

Feasibility

• Action budget: one subject action and one camera move per short clip. Revise

briefs demanding many sequential actions, several locations, exact mechanisms, or multiple full dialogue lines.

• Shot structure: state one continuous unbroken take, or an explicit sequence:

``text SHOT ONE: wide aerial of a desert highway at dawn, a single red car speeding through. HARD CUT. SHOT TWO: interior close-up, the driver's hands drumming the wheel to the radio. HARD CUT. SHOT THREE: from the roadside, the car shrinking into the heat haze. Warm engine hum under one continuous music bed across all three shots. ``

Consecutive shots must contrast hard (scale, location, color) or the cut blends into a continuous take; each shot needs its own beat; one music bed can run across cuts.

• Contradictions to catch: locked-off camera plus tracking; extreme close-up plus

establishing view; exact frame preservation plus major geometric change; one continuous shot plus hard cuts; production-critical generated typography with no post fallback; guaranteed speaker identity across separate generations.

• Reserve for deterministic post when exactness is a success condition:

typography, subtitles, logos; frame-accurate sync; final mixing; precise mechanisms; cross-generation speaker identity. Generation creates footage and causal intent, not a compositor or final mix.

Verdict

Return exactly one state, with a reason, next action, and a compact handoff ([templates/brief.md](templates/brief.md) when it should be reusable):

• READY: route, assumptions, handoff. Recommend a draft first when the concept is

unproven.

• NEEDS INFO: only the blocking questions.
• REVISE: name the conflict and the minimum repair.

Non-blocking warnings go under Production risks, not a fourth state. Field names and limits belong to the API reference; flag intent conflicts and leave schema validation to flux-3-generate.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: black-forest-labs
• Source: black-forest-labs/skills
• License: MIT
• Homepage: https://docs.bfl.ai

Install and usage instructions live in the source repository linked above.