an

AI-driven structured animation in Python. The user is the director; an AI agent (Claude Opus 4.7) is the assistant orchestrator; existing animation libraries (a custom 2D-cutout runtime, Manim, Remotion) are the executors.

pip install an

Renamed from anima (PyPI conflict). Repo: https://github.com/thorwhalen/an.

What works today

an check                                                  # diagnose backend system deps
an init my-scene                                          # create a fresh project
# edit scene.md ...
an validate my-scene                                      # schema + semantic validation
an render my-scene                                        # → output/main.mp4 (offline defaults)
an render my-scene --tts elevenlabs --lipsync whisper     # real speech, word-aligned visemes
an render my-scene --parallel auto                        # per-shot threads (~N× speedup on N-shot scenes)
an preview my-scene                                       # live in-browser preview; reloads on edit
an iterate my-scene "make Maya laugh longer and warmer"   # free-text → IR patch → invalidate caches
an render my-scene                                        # re-renders only the affected shot

# Character authoring (Phase 11a)
an character new maya --seed maya-warm                    # generate a DiceBear-backed character
an character new bob --offline                            # offline-only: deterministic geometric fallback
an character mouths maya                                  # regenerate the 9-shape default mouth set
an character validate maya                                # check parts, mouth set, pivots
an character silhouette maya --other bob                  # silhouette test (IoU score)
an character preview maya --open-browser                  # HTML viewer cycling all 9 visemes

The defaults run without any API keys: offline TTS produces silent audio of the right length, offline lip-sync deterministically generates viseme tracks. To get real audible speech, set ELEVEN_API_KEY and pass --tts elevenlabs. For word-aligned mouth shapes, pip install faster-whisper and pass --lipsync whisper. For free-text editing via an iterate, set ANTHROPIC_API_KEY.

A 30-second tour

A project is a small directory:

my-scene/
├── scene.md            # human Markdown — what you and the agent edit
├── ir/scene.json       # Pydantic-validated SSOT (auto-synced)
├── assets/             # characters, environments, voices, styles
├── artifacts/          # audio, viseme tracks, per-shot mp4s (content-hash cached)
├── output/             # final mp4s
└── .an/                # decisions log + agent memory

Authoring happens in scene.md:

# Park Bench

```yaml meta
title: Park Bench
duration: 12
fps: 24
resolution: { width: 640, height: 360 }
```

## Shot s1 (cutout)

```yaml shot
duration: 6
camera: { move: push_in }
```

```yaml entities
- { kind: environment, id: park_bg, store: environments, ref: park }
- { kind: character,   id: charlie, store: characters,   ref: charlie-v1 }
- { kind: character,   id: maya,    store: characters,   ref: maya-v1 }
```

```dialogue
charlie [thinking]: Did you ever wonder why we always meet here?
maya [amused]: Because the pigeons trust us.
```

an render produces an mp4 with two visually-distinct characters (per-id palette: skin/clothing/hair), animated mouths over the dialogue lines, eye-blinks every ~4 seconds, eyebrows tilted by emotion, a sky/grass park background, and a slow camera push-in.

A 3-minute tour

an separates a scene into three layers:

1. Narrative — scene.md. Markdown with structured fenced blocks: yaml meta, yaml shot, yaml entities, yaml actions, dialogue. What you and the agent edit.
2. Scene Graph — ir/scene.json. Pydantic-validated, renderer-agnostic. The single source of truth. Diffable. Pipeline stages (audio synthesis, lip-sync) write into the JSON; an sync keeps it consistent with the Markdown using mtime-newer-wins.
3. Render Code — generated per-backend (cutout JSON for the JS runtime, Manim Python, Remotion TSX). Disposable; never edited by hand.

Composition

Authoring is fluent in Python and flattens to a canonical timeline:

from an import sequence, parallel, tween, delay, flatten

action = sequence(
    tween("charlie/torso", "rotation", to=10.0, duration=1.0),
    delay(0.5),
    tween("charlie/torso", "rotation", to=0.0, duration=1.0),
)
flat = flatten(action)
# [FlatAction(start=0.0, end=1.0, ...), FlatAction(start=1.5, end=2.5, ...)]

The same shape is also writable in markdown via a yaml actions block:

- { kind: tween, target: charlie/torso, property: rotation, to: 10.0, duration: 1.0 }
- { kind: tween, target: charlie/torso, property: rotation, to: 0.0,  duration: 1.0, start: 1.5 }

Persistence — the project mall

Everything long-lived (assets, artifacts, decisions, scene state) goes through a dol-backed MutableMapping mall:

from an import build_project_mall

mall = build_project_mall("my-scene", ensure=True)
mall["voices"]["maya-warm"] = {"provider": "elevenlabs", "voice_id": "..."}
mall["scenes"]["main"]  # returns a SceneIR

End-to-end orchestration

from an.orchestrate import orchestrate

report = orchestrate("my-scene")
# report.success: bool
# report.output_path: Path
# report.validation:  ValidationReport
# report.verifications: list[VerificationReport] from each verifier

The default verifier chain runs LayoutLintVerifier (pre + post) and MediaQualityVerifier (post). Pass your own list to swap in VisionLMVerifier (Claude vision QA) or HumanInTheLoopVerifier (interactive approval).

Free-text iteration (the spec's signature loop)

from an.orchestrate import iterate

result = iterate("my-scene", "Make Maya's response a bit longer and more affectionate")
# result.summary:           "Extended Maya's reply..."
# result.patches:            [Patch(op='set', path='timeline/1/dialogue/0/text', value=...), ...]
# result.affected_shots:     ['s2']
# result.success / .error / .new_scene / .validation

The patches are validated against the schema and persisted; affected shots' cached mp4s are invalidated so the next an render regenerates only those.

Architecture

For a deeper as-built reference (module-by-module map, control flows, key invariants, content-hash caching strategy), see misc/docs/architecture_as_built.md. The seven research reports next to it cover the design space the system was built against.

Injecting word timings (no whisper redundancy)

When the caller already has authoritative word-level alignment data (e.g. from a separate lyric-alignment pipeline), an can skip its own transcription pass entirely:

from an.audio import StaticWordTimings, WordTimingsLipSync
from an.orchestrate import orchestrate

timings = [("hello", 0.5, 1.0), ("world", 1.2, 1.8), ...]
lipsync = WordTimingsLipSync(StaticWordTimings(timings, label="my-aligner"))

orchestrate("my-scene", lipsync=lipsync)

orchestrate(..., tts=, lipsync=, parallel=) accepts either provider name strings or instances. Plug in any WordTimingProvider (structural protocol with name: str and words_for(audio, transcript=) returning (text, start, end) tuples). muvid uses this hook to feed lacing alignment-store timings straight into the cutout pipeline.

What's not in v0.1

• 3D animation, generative video, interactive output, SaaS hosting, music/sound-effect generation, in-house GUI, or editing of pre-existing video footage. an synthesizes; it does not cut.
• The Manim backend works for placeholder title cards but isn't doing real shot-to-Manim translation; Remotion + whiteboard are skeleton implementations that respond correctly to can_render but can't produce video yet.
• Lip-sync for face-baked characters. Characters sourced from DiceBear (or any external_avatar descriptor) carry their face inside the head SVG, so the compiler suppresses both the overlay mouth and the viseme channel — they speak without moving their mouths. Hand-rigged characters lip-sync normally; see examples/promote_demo/.
• Multi-scene projects — "main" is the only scene key supported today.
• Fully offline rendering. The JS runtime loads PixiJS from a CDN, so a cold render needs network access even though TTS and lip-sync default to offline.

SVG character art has shipped — descriptors drive real sprites through svg_sprite visuals, not the placeholder geometry an earlier version of this list described.

Reference

• misc/docs/architecture_as_built.md — module map, control flows, invariants, caching strategy.
• misc/docs/ — seven design-space research reports (~250 KB).
• misc/CHANGELOG.md — phase-by-phase what shipped when.
• .claude/skills/ — three skills (an, an-spec, an-dev) the agent uses to drive the package.
• examples/ — single_character/, walk_demo/, park_bench_cartoon/ — the canonical demo scenes.