funman300
1605e6effd
The open question was whether a response deserializer DESCENDS a wrapper or PROBES for
one. Three roots spend an identical three tokenizer calls before dispatch, yet we serve
some bodies wrapped and some flat, and not all of those could be right.
TOKEN ENUM, decoded from the class table at DAT_18023dd40 and the switch in the
classifier FUN_1801c67a0 (the push/pop arms key off container state 2 = object,
3 = array):
9 START_OBJECT case 0x64, pushes state 2
10 END_OBJECT case 0x65, pops state 2
11 FIELD_NAME confirmed independently: FUN_18013bd40 tests +0xd0 == 0xb then
atom-hashes the string at +0xf8
12 START_ARRAY case 0x66, pushes state 3
13 END_ARRAY case 0x67, pops state 3
1 error the caseD_78 sink
So the three tokens are `{`, the first FIELD_NAME, and the token opening that field's
value. The envelope is structurally required and its name is NEVER hashed, which is why
FutCreatePack's ladder has no arm for createPackResponse (0xbe) and does not need one.
Coverage for that absence: the ladder has exactly four arms (0xec, 0x16e, 0x1dd, 0x264)
and 0xbe does not occur anywhere in the full 4702-char decompile, printed in full.
The competing reading rested on a factual error. It claimed the /purchased root spends
the same three tokens. FUN_180124ee0 spends TWO and hands off to FUN_18013bd40, which
spends the third. Same total, split across two functions. /purchased never was a
counterexample.
THE BUG THIS FOUND IS NOT THE ONE THAT WAS PREDICTED. The doc expected starterPack,
squad and userData to be swallowed on POST /user. They are not. FutCreateUser
(0x18014cc60) has ladder arms for exactly the five keys we send, and four of them
dispatch correctly at the outer level. The one that does not is `login`: its name is
eaten as the anonymous envelope and its value as the third token. It has an arm, so the
client wants it, and it has never once been delivered.
The second-order consequence matters more than the first. The key order of that dict is
load-bearing and nothing said so. Put userData first and the client loses the entire
user record, silently, with no error and no log line. That warning now sits in the code
next to the dict, which is the only place someone about to reorder it would look.
No behaviour change here. The utas_server.py edit is a comment. 439 contract checks
still pass. The probable proper fix, wrapping all five keys one level down inside a
single envelope key, is a hypothesis with a mechanism rather than a proven fix, and it
touches the login path, so it is not made here and would go behind a flag defaulting
off.
Writeup is section 2 of docs/plan-2026-08-05-pack-opening.md, added by the previous
commit. Opened by this and still UNKNOWN: GET /hub is answered with a flat two-key
body, which under this rule a three-token root would silently truncate, but there is no
FutGetHubServerResponse class and neither atom has a code xref, so /hub may not go
through a generated root at all.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
OpenFUT
Offline Ultimate Team — like SPT, but for FIFA 23.
OpenFUT replaces EA's retired FUT servers with a fully offline, single-player backend. You own FIFA 23 legitimately. You just want to keep playing after EA shut down the servers.
Repositories
| Repo | Purpose |
|---|---|
openfut-core |
Game-independent offline FUT backend |
openfut-bridge |
FIFA 23 integration layer + reverse-engineering proxy |
Architecture
FIFA 23 client
│
▼
┌─────────────────┐
│ openfut-bridge │ ← intercepts FUT traffic, maps routes, logs unknown
└────────┬────────┘
│
▼
┌─────────────────┐
│ openfut-core │ ← offline FUT backend: profiles, packs, squads, SBCs
└─────────────────┘
│
▼
SQLite database
Core is game-independent. It speaks a clean REST API and knows nothing about FIFA 23 internals.
Bridge is FIFA-specific. It speaks FIFA 23's wire protocol and translates it into Core API calls. Bridge is where all reverse engineering work happens.
Current Status
| Feature | Status |
|---|---|
| Local profiles + clubs | ✅ Working |
| Coin system | ✅ Working |
| Pack generator | ✅ Working |
| Card collection | ✅ Working |
| Squad builder | ✅ Working |
| Objectives engine | ✅ Working |
| SBC engine | ✅ Working |
| Match rewards | ✅ Working |
| NPC transfer market | ✅ Working |
| Statistics | ✅ Working |
| FIFA 23 integration | 🔴 Reverse engineering in progress |
| Chemistry calculation | 🟡 In progress |
| Full Draft mode | 🟡 In progress |
| Squad Battles AI generator | 🟡 In progress |
| Objectives claim flow | 🟡 In progress |
Running
# Start the offline backend
cd openfut-core
cargo run
# Start the proxy (for traffic capture / FIFA integration)
cd openfut-bridge
cargo run
Core listens on http://127.0.0.1:8080 by default.
Bridge listens on http://127.0.0.1:8443 by default.
Design Principles
- Offline-first. No EA account required. No internet connection needed.
- Single-player only. This is not a multiplayer server emulator.
- Data-driven. All cards, packs, SBCs, and objectives are JSON files. Everything is moddable.
- Clean architecture. Core has zero knowledge of FIFA 23. Bridge has zero game logic.
- No copyrighted assets. No real player images, no EA trademarks in data files.
Disclaimer
This project is not affiliated with EA Sports. You must own FIFA 23 legitimately to use this software. This project does not bypass any ownership verification and is intended only to restore offline playability of a game whose online services have been retired.