render-feed

name	render-feed
description	Generate and verify paid fal.ai video renders for the DoomScrum swipe feed. Use when: "regenerate content", "render the feed", "new renders", "bake-off a model", "switch video model", "re-roll a clip", or any task that spends FAL money. Trigger: /render-feed.

render-feed

Paid renders for the swipe feed. Every dollar is tracked; every clip is transcript-verified before it counts.

Money rules

• Unit cost is quoted by fal::unit_cost(cfg) (snapped clip duration × model price). Spend cap lives in doomscrum.toml (max_total_spend_usd); raise it only with the owner's say-so. Provenance = render JSONs in .doomscrum/renders/<spec-sha>/<render-id>.json; the sum of their cost_estimate_usd (all statuses, including retired) is total spend.
• To remove a render from the feed without losing spend provenance, set its status to "retired" — never delete render dirs.
• FAL key: env FAL_API_KEY/FAL_KEY or ~/.secrets. Never print it.
• Failed seedance moderation (422 after render) is unbilled; silent duds are billed. Budget ~1.3x for re-rolls.

Model facts (verified on fal 2026-06-10 — re-verify before adopting)

Authoritative table: src/providers/fal.rs (model_price_per_second, clip_duration, per-family request schemas) + comments in doomscrum.toml.

Model	$/s w/ audio	Cap	Note
bytedance/seedance-2.0/fast/text-to-video	0.2419 @720p	15s	hero: native word-synced on-screen captions
fal-ai/sora-2/text-to-video	0.10	12s	won 8s script-fit bake-off
fal-ai/kling-video/o3/standard/text-to-video	0.112	15s	1080p, structured multi_prompt
fal-ai/veo3.1/lite	0.05 @720p, 0.08 @1080p	8s ("4s"/"6s"/"8s")	cheapest dialogue; 9:16 native
fal-ai/pixverse/v6/text-to-video	0.060 @720p (0.025 @360p silent)	15s	draft tier for prompt iteration

Schema check for a new model: curl -s "https://fal.ai/api/openapi/queue/openapi.json?endpoint_id=<id>".

Iron rule: no unverified paid render

After every render:

python3 scripts/check_script_fit.py <mp4> "<planned script>" [--words-json out.json]

--words-json saves word-level timings (caption overlays for the demo).

COMPLETE (exit 0) or it gets re-rolled/retired. The planned script comes from the storyboard in .doomscrum/storyboards/. Word budget is (duration - 2) * 2.0 words (src/distill.rs); do not pad scripts past it.

Commands

cargo build --release
./target/release/doomscrum generate --root . [--model <id>] [--spec <filter>]

Run long renders in the background with the absolute binary path and --root pinned — cwd drift breaks relative paths. rm is hook-blocked; use /usr/bin/trash.

Render gotchas (earned, not theoretical)

• Exhausted fal balance masquerades as everything else (2026-06-11): a locked account produced storage 403s, LTX 422s at result-fetch, and 600-poll queue timeouts across models before any request said "Exhausted balance". When two unrelated failure shapes appear in one batch, probe with a cheap submit and read the 403 body before debugging models. Our spend cap tracks OUR ledger, not the prepaid fal balance.

• ltx-2.3 is banned from the content mix (verified 2026-06-11): 1 of 4 clips had catastrophic diction ("no vibes merges, capiche" -> "No merges. Copy, sheep."), 1 cut its last word. veo3.1/lite carries the cheap weight.

• Transcription fallback: fal storage upload may 403 independently of the queue; check_script_fit.py falls back to Deepgram through the exact Mint route derived from MINT_BASE_URL, using __mint.deepgram.default__ — direct binary upload, no storage hop and no raw Deepgram key in the agent process.

• Scripts must spell numbers as words and skip exotic interjections ("capisce") — voice models garble them and the transcript gate eats the miss. The scriptwriter prompt enforces this; don't hand-write scripts that violate it.

• Seedance output moderation rejects "unhinged" / "deadly serious" phrasing.

• Accented narrators garble words unless the prompt demands "crisp, clearly intelligible English".

• fal rejects data: URIs — upload via https://rest.alpha.fal.ai/storage/upload/initiate + PUT.

• Stale storyboards for archived specs masquerade as budget bugs — trash .doomscrum/storyboards/ before a full regen.