The Decoder warned that my port "presumably models one title". Checking that found a real behavioural split, and the code was right where I expected it wrong and wrong where I did not. My prediction FAILED first: I expected the port to be inventing a plate on a (B)-reached title, because flow.json's scope_why says that is deliberately not claimed. It is not inventing -- the call site cites a measurement from 2026-08-30, the plate IS re-drawn after (B). scope_why was the stale thing, and is corrected. 🔴 BUT THE TWO PATHS DIFFER, AND A `why` CLAIMED THEY DO NOT. That call site says "the plate re-appears by the SAME path, with the same shared clock, as it does on boot. Whatever the boot does, the return does." Filmed: before: el=1.39 view_u=0.00 overlay_u= 0.00 plate absent el=1.53 view_u=8.67 overlay_u=244.67 plate present The overlay clock jumped 0 -> 244.67 in ONE frame. The plate POPPED, where the boot fades it across its declared 214->236. Cause: `_overlay_process` detected "static diagnostic mode" as `_sequence.is_empty()`, and `_sequence` is populated only by `--boot`. So `--menu` matched it too and the menu's return took the `--screen --overlay` diagnostic branch, which poses the overlay at settle_time() by design. A proxy for one mode that silently caught another. Fixed by gating on the flag itself -- `_static_overlay`, set only by `--overlay=` without `--boot`. Verified both directions: diagnostic still poses: --screen=title --overlay=press_start --time=4 -> "overlay press_start at t = 240.00 units, drew 2" return now shares the clock: overlay_u == view_u on every filmed frame, plate at its 0.1377 floor through 168 units boot path unchanged: plate reaches full alpha at t=236, boot completes 10.46 s ⚠️ WHAT I DID NOT OBSERVE, stated rather than glossed: the plate actually RISING on the return path. `--script` quits when the walk settles, so the film stops at ~168 units and never reaches 214. The rise is established on the BOOT path (measured earlier: 0.1457 at 210 u, 0.2142 at 236 u) and the return now provably takes that same branch with an identical clock -- but the final rise on this path is inferred from path identity, not filmed. ⚠️ And whether the GAME fades the returned plate is still unmeasured. The 7.3 s between (B) and the pulse returning is consistent with a transition plus the declared fade, but that is consistency, not a measurement of the ramp on this path. Recorded in scope_why. Not settled: finding 3, no surviving cause; the clock origin, which the Decoder reports blocked -- no capture contains the title, because it sits on the far side of a 137.7 s movie and the runs were too short; the ~1.0-1.2 menu residual. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018AHUQvXGyNcKonSEWsgWcX
Sylpheed
A clean-room reverse engineering and port project for Project Sylpheed: Arc of Deception (Xbox 360, 2007).
Three things live here, in one repository so that a change spanning them lands as one commit:
| The decoders | crates/sylpheed-formats — the disc's formats, read and verified disc-wide |
| The port | port/ — a Godot 4 project, plus crates/sylpheed-export which converts a disc into the open asset tree it reads |
| The corpus | docs/re/ — what has been reverse engineered, with its evidence, its retractions and its dead ends |
You need your own copy of the game. No game content is in this repository and none ever will be. The exporter reads the disc you supply.
The oracle is the real game
sylpheed-cliand the Explorer are tools for verifying our decoding. They are hypotheses under test and they have been wrong. When something must be checked against the truth, the truth is the game running in Xenia Canary, captured — not any renderer of ours.
This is stated first because getting it backwards is the most expensive mistake this project has made.
Layout
crates/
sylpheed-formats/ the decoders. Disc-wide verified; the corpus is its spec
sylpheed-cli/ headless tools -- render a screen, dump a table, probe audio
sylpheed-viewer/ the Explorer: a human's window onto the disc. STATIC data only
sylpheed-export/ disc -> the open, moddable asset tree
port/ the Godot 4 project. Reads open formats ONLY
authored/ decisions that are NOT on the disc, each with its reason
data/
base/ generated by the exporter. Gitignored, never hand-edited
mods/ drop-in overrides. Yours
docs/
re/ the corpus: findings, refutations, method traps
game/ how the game is navigated -- menus, modals, flight
port/ the port's mission, its handoff contract, modding rules
-- and RUNNING.md, which is how you actually start it
agents/ how the agent team works together
tools/ capture harnesses, probes, the share tool
exchange/ transient inter-agent files. NOT in git
docker/ the agent containers
Where to start
docs/re/INDEX.md— what is decodeddocs/re/REFUTED.md— what has been tested and dieddocs/re/METHOD.md— traps this project has already paid fordocs/game/navigation.md— how the game is navigateddocs/port/MODDING.md— why the asset tree looks the way it does
Xenia Canary is a separate repository: it is a fork tracking upstream, and it carries our instrumentation.
Conventions
Confidence is per claim, never per document: ✅ CONFIRMED · 🟡 PROBABLE ·
❔ HYPOTHESIS · ❌ REFUTED. A withdrawn result is kept with its reasoning
rather than deleted — that is why the numbers here can be trusted.