Session script — software

Claude Fable 5.1 (claude-fable-5-1), reasoning effort max, in the Claude Code CLI (version 2.1.285, permission mode auto). All times are America/New_York (EDT). The session began just after midnight on 2026-09-30; the film turn ran from 00:02:24 to 00:52:16. Background-task notifications opened turns at 00:55:15 and 01:02:41; the provenance turn began at 01:18:12.

Verbatim user turns, condensed model and tool activity. Tool payloads (the code written, the frames and spectrograms inspected, the search results read) are summarised; the code survives as the files in this repository, the research as ESSAY.md, and the working notes as notes/design-log.md.

Turn 0 — Local commands

Before the first prompt the user ran two slash commands. Their recorded output:

Set model to Fable 5.1 and saved as your default for new sessions

Set effort level to max (this session only): Maximum capability with deepest reasoning. May use excessive tokens resulting in long response times or overthinking. Use sparingly for the hardest tasks.

Turn 1 — User (00:02:24)

The message was a pasted block of text (the harness wrapped it as pasted content); its wording, verbatim:

Software is incredibly malleable and non-linear. You know.

Create a film which gives the viewer a visceral understanding of how twisted, exotic, and deep software can be. I expect to see beautiful representations of the tower of abstraction, and raw display of the expressiveness and power of language.

As you work on this task, write a research essay/journal/blog about how you created the film. Include all of the research you did on software, philosophy, aesthetics, popular trends, art theory, representation theory, film theory, etc, whatever that helped you come to a design and why you chose it. Keep everything in layman terms. Include rationale, like why it’s elegant or catchy. And explain your artistic judgement.

Use mise, uv, and python to create the dilm. Use any dependencies you like as long as they’re version controlled and builds are reproducible.

Turn 1 — Assistant and tool activity, condensed

57 model requests, 125 tool calls (Bash 49, Read 52, WebSearch 19, ToolSearch 3, Write 1, TaskStop 1). 52 images were viewed, all rendered by this session's own code; there were no subagents.

1. Deliberation (00:02 to 00:10). The first request ran eight minutes and produced 32,557 output tokens, 32,214 of them reasoning, before any tool call. It settled the argument with Brooks's "software is invisible and unvisualizable" (film a descent, not a diagram), the title All the Way Down, the spine (a Powers of Ten zoom, a factor of ten per layer, from a printed word to atoms), the rule that everything on screen must be a real artifact, the six movements, the amber-to-blue palette, the IBM Plex typography, a score synthesised in numpy with a Shepard–Risset glissando driven by the zoom's own depth function, the frame-as-pure-function-of-time engine, the toolchain (mise, uv, Python 3.13, numpy, skia-python, the ffmpeg bundled in the imageio-ffmpeg wheel), and the plan to research and write the essay alongside the build.
2. Reconnaissance and toolchain (00:10 to 00:12). Found an empty git repository with no commits; mise 2026.9.1, uv 0.12.2, a system ffmpeg, clang 21 and objdump; an Apple M5 with 10 cores and 16 GB. Queried PyPI for macOS arm64 wheels (skia-python 144.0.post2 ships cp313 wheels) and mise for Python versions. Wrote mise.toml (python 3.13.15, uv 0.12.2, UV_PYTHON_DOWNLOADS=never, the build tasks), pyproject.toml with three exact pins, .python-version and .gitignore; trusted and installed the toolchain; locked and synced; verified the imports and the bundled ffmpeg 7.1.
3. Real materials (00:11 to 00:14). Vendored six IBM Plex faces with their license from IBM's repository. Wrote a fourteen-line C miniature of CPython's LOAD_CONST, compiled it with clang at -O2 for arm64, disassembled it and vendored the listing and its 56 raw bytes (film/data/), noting that add x9, x9, #1 is Py_INCREF and that bit 30 of its encoding turns it into sub. Fetched CPython v3.13.15's generated_cases.c.h and vendored the LOAD_CONST case with its URL and line number. Smoke-tested skia (typeface loading, text metrics, gradients, blur, numpy interop) and viewed the result (one image).
4. Research (00:14 to 00:16). Loaded the WebSearch and WebFetch schemas and ran nineteen web searches, fifteen of them in one batch: Eames's Powers of Ten; Ikeda's datamatics and test pattern; Reich's Music as a Gradual Process; LeWitt's Paragraphs on Conceptual Art; Brooks's No Silver Bullet; Dijkstra's The Humble Programmer; bytebeat and the forty-two melody; the Shepard–Risset glissando and Dunkirk; the demoscene's heritage listing; the It runs Doom and Bad Apple!! memes; Thompson's Reflections on Trusting Trust; Snow's Wavelength and Frampton's Zorns Lemma; McLaren's Synchromy; Karpathy's Software 3.0 and vibe coding; Nees's Schotter and Vera Molnár; then Anadol's Unsupervised, the "rocks we tricked into thinking" meme, and Tufte's layering and separation. The findings were logged in notes/design-log.md.
5. Engine (00:16 to 00:18). Wrote film/config.py, film/canvas.py (skia drawing helpers and easing in a fixed 1920×1080 design space), film/timeline.py (cues, crossfades, a vignette and ±1 dither; every frame a pure function of time), film/encode.py (worker processes streaming raw frames into ffmpeg) and the film command line. A throwaway scene rendered 30 frames to H.264 and probed correctly.
6. The descent (00:18 to 00:29). Inspected the real bytecode of print("hello, world") with dis. Wrote film/scenes/common.py (the terminal; the letter h rendered off-screen and its pixels read back; twelve layers from screen to atoms including a live full adder and a CMOS NAND; the depth gauge), prologue.py, descent.py and the cue list. Rendered seventeen stills across the layers and reviewed every one (seventeen images): all layers correct, but gauge labels clipped, captions collided with content, memory addresses fell off-screen, and the focal atom was a dopant.
7. The rest of the film (00:29 to 00:33). Fixed those four problems (gauge moved, gradient backing bands, address column moved, dopant rule changed). Wrote film/lam.py, a small lambda calculus with capture-avoiding substitution, and confirmed that two times three reduces to six applications of f in seven steps. Wrote film/mandel.py, interlude.py (fifty-six bytes through five lenses, then the bit flip), language.py (three rules, Church numerals, the reduction, the Y combinator, the bytebeat oscilloscope, the Mandelbrot condensation and zoom, a quine cascade), loop.py (the accelerating cyclic descent) and coda.py; verified the quine and that the flipped bit adds exactly 2¹⁹⁰. Rendered twenty-five stills and reviewed them all (twenty-five images): the λ rendered as a missing-glyph box, and two layouts collided.
8. Type and sound (00:33 to 00:36). Confirmed that Plex Mono has no Greek and Plex Sans does; added per-glyph fallback so a missing character borrows the sans face inside the mono cell. Fixed the collisions and the Mandelbrot's undecided colour. Wrote film/audio.py: key clicks, a Shepard–Risset fall whose phase is the same depth function the picture uses, a sub-tone, Ikeda-style clicks at each layer, the fifty-six bytes played as 8 kHz samples, the bytebeat t*(42&t>>10), a Reich-style two-tempo pattern under the coastline, pings for the quine cascade, the accelerating fall for the loop with a hard cut, the reversed fall and a chord for the coda. The first render crashed on adding signals of different lengths; a padding helper fixed it. Measured the loudness profile and lowered the bytebeat.
9. Preview (00:36 to 00:37). Rendered the whole film at 640×360, 15 fps, in twenty seconds in the background while writing the README. Built contact sheets (one frame every four seconds) and a log-frequency spectrogram of the score, and reviewed them (three images): every movement in place; the spectrogram shows the parallel falling diagonals of the descent, the buzz's harmonics, the bytebeat block, the phasing lattice, the loop's steepening curves and the cut.
10. The establishing shot (00:37 to 00:39). Added a ten-second tower shot before the zoom (the terminal shrinks into the top slab of a labelled stack of twelve, then grows back while the miniature gauge fades in), warmed the Shepard tone's range, pinned libx264 to eight threads for byte-identical output, reviewed four stills (four images) and adjusted the slab fade.
11. Essay and the first full render (00:39 to 00:44). Launched the 1080p render in the background and wrote ESSAY.md, about 8,900 words, in one pass. The render "completed" with exit code 0 but held only 132 seconds: ffmpeg's -shortest had ended the encode once it read the audio file ahead of the slow frame pipe, and piping the log through tail had masked the broken pipe.
12. Fixes and verification (00:44 to 00:52). Rewrote the encoder as two passes (video alone, then a mux with the audio trimmed to the video's length) and relaunched. Verified the encoder on a short clip with and without audio, that the same frame hashes identically in two fresh processes, and that uv lock --check passes. Rendered fifteen stills for the essay and regenerated the spectrogram into stills/; inserted the images and the encoder problem into the essay; verified every image link; updated the README; saved one memory file about this collection's brief. Proofreading the essay found three wrong on-screen counts (t*(42&t>>10) is twelve characters, not fifteen; z=z*z+c is seven, not nine; fourteen of the fifty-six bytes are printable, not nine), so the running render was stopped, captions and text corrected, one still re-rendered and the render launched a third time. Confirmed a four-second clip encodes byte-identically twice. Loaded the Monitor schema (unused) and ended the turn with a status line at 00:52:16, with the render about eight minutes from done.

Turn 1 result

The turn closed on a short status message: the render was running in the background with corrected captions; the engine, scenes, score, essay, README, design log and reproducibility checks were complete; the finished film would be verified when the render exited.

Turn 2 — Background-task notification (00:55:15)

The harness reported that the third full render had failed with exit code 137.

Assistant and tool activity, condensed

5 requests, 4 tool calls (all Bash), one background command.

1. Read the render log and the system state: the parent process had been killed at frame 3,780 (the workers then hit broken pipes), memory was the cause, and no render process survived.
2. Diagnosed the mechanism: Pool.imap submits every frame at once and has no backpressure, so on cheap scenes the workers outran libx264 and thousands of six-megabyte frames accumulated in the parent until the operating system killed it. Replaced it with a bounded window of apply_async futures (twice the worker count in flight), verified the clip output was byte-identical to before, and recorded the bug in the design log and the essay's problems section.
3. Launched the fourth full render in the background, confirmed mise run check passes and that the parent process now held 171 MB, and ended the turn with a status line at 00:56:47.

Turn 3 — Background-task notification (01:02:41)

The harness reported that the fourth render had completed (exit code 0).

Assistant and tool activity, condensed

3 requests, 5 tool calls (Bash 2, Read 3), three images viewed.

1. Read the log (6.3 minutes), probed the file (11,273 frames, 375.767 s, 1920×1080 at 30 fps, H.264 plus AAC 48 kHz stereo, 289,737,509 bytes) and extracted four full-resolution frames from the encoded file; viewed three (the machine-code layer, the flipped bit, the second tower of the loop): crisp.
2. Corrected the render-time claims in the essay and README (about six minutes, not ten), listed the repository tree (2,573 lines of Python) and confirmed nothing was committed.

Turn 3 — Delivered response

The film is finished and verified, the essay is written, and the build is pinned and reproducible. dist/all_the_way_down.mp4 is 6 minutes 16 seconds at 1920×1080, 30 fps, with a synthesised score (11,273 frames, 290 MB); everything on screen is real (the font's actual pixels, real framebuffer offsets, CPython 3.13.15 bytecode disassembled at render time, the real LOAD_CONST C source, real clang output, a real bit flip, real beta-reductions, a real quine), and the Shepard tone is computed from the same depth function that drives the zoom. ESSAY.md is about 9,100 words with sixteen stills. The build is mise install && mise run setup && mise run render; frames hash identically across processes and the same clip encodes byte-identically; a full render took 6.3 minutes. Two bugs were named (the -shortest truncation and the missing backpressure), both fixed and documented. Nothing was committed; dist/ was left tracked so the user could decide about the 290 MB film; the essay could be published as a shareable page on request.

Turn 4 — User (01:18:12)

Create a metadata.toml file as described in ~/repos/uncanny.fyi/AGENTS.md for the current session. Be sure to create the references files as well, such as script.md containing a session script and notes.md with session notes.

(The user wrote the absolute path of the guide; it is shown here with the home directory as ~, as the guide's privacy rule requires.)

Assistant and tool activity, condensed

1. Read the uncanny.fyi operating guide (AGENTS.md) and the relevant parts of its README; listed every source project in the collection; read the previous Fable 5.1 session's metadata.toml, script.md and notes.md (the alignment project) and one published artifact's script and notes as format references; gathered this repository's file timestamps.
2. Loaded the claude-api skill bundled with the harness for Claude Fable 5.1's list rates, and confirmed the cache read and write multipliers in its prompt-caching notes.
3. Profiled this session's own transcript (837 records) and wrote a measurement script in the session scratchpad: model requests deduplicated by message id, per-turn tokens and cost, request in-flight intervals, tool intervals, tool counts, images, background commands, turn boundaries checked against the harness's turn_duration records. Nothing from the transcript was copied into the project beyond the aggregates.
4. Generated metadata.toml from the measured numbers (nested format, with video-path and no web-path), wrote this script.md and notes.md, then validated the TOML, the referenced paths and the absence of home-directory paths.

Automated environment updates, harness reminders and the notification text itself are omitted from this script; user wording is verbatim, including the typo "dilm".