utxo/FINAL_RIP.md

Final codec rip — luxfi/utxo

Activation 2025-12-25T16:20:00-08:00. No backwards compat, no shim, no env var. The wire is ZAP. Delete the legacy.

Surface to delete

Per-fx vm.go (8 files)

Drop CodecRegistry() codec.Registry from the VM interface. Drop the Codec field from TestVM and its CodecRegistry() accessor. Drop the luxfi/codec import. Files:

• secp256k1fx/vm.go
• mldsafx/vm.go
• slhdsafx/vm.go
• ed25519fx/vm.go
• secp256r1fx/vm.go
• schnorrfx/vm.go
• bls12381fx/fx.go (VM interface lives in fx.go for this package)

Per-fx fx.go Initialize (9 files)

Drop the c := fx.VM.CodecRegistry() block + the RegisterType chain. The wire schema is static at compile time; nothing to register. Each Initialize keeps the VM cast + logger init and otherwise becomes a no-op. Files:

• secp256k1fx/fx.go
• mldsafx/fx.go
• slhdsafx/fx.go
• ed25519fx/fx.go
• secp256r1fx/fx.go
• schnorrfx/fx.go
• bls12381fx/fx.go
• nftfx/fx.go — embeds secp256k1fx.Fx, has its own RegisterType chain
• propertyfx/fx.go — embeds secp256k1fx.Fx, has its own RegisterType chain

Root package

• api.go — replace codec.Uint32 / codec.Uint64 with jsonutil.Uint32 / jsonutil.Uint64 (new package) or unqualified uint32/uint64 with hand-rolled JSON. Cleanest: replicate the JSON-string-quoted types locally in utxo/jsonutil/.
• atomic_utxos.go — drop codec codec.Manager field + ctor param; parse cross-chain bytes through wire.WrapUTXO(b).
• flow_checker.go — replace wrappers.Errs with an inline 5-line errs struct or move to utxo/internal/errs/. Drop the luxfi/codec/wrappers import.
• transferables.go — drop c codec.Manager from SortTransferableOutputs, IsSortedTransferableOutputs, VerifyTx. Sort key is now out.Bytes() (the ZAP wire envelope returned by the wireSerializable interface). Verify is unchanged.
• utxo_state.go — drop codec codec.Manager field + ctor params; encode/decode through utxo.WireBytes() / utxo.WrapUTXOBytes().

wire/discriminator.go

Doc-comment-only reference. Comment text is correct historical context; no import statement. Leave it.

Activation invariant

The new network's genesis is at unix 1766708400. Every block produced after that point uses ZAP-native UTXO encoding. No legacy codec UTXOs exist on disk or on the wire.

Cascade

After this lands, every luxd caller of:

• lux.SortTransferableOutputs(outs, Codec) → lux.SortTransferableOutputs(outs)
• lux.IsSortedTransferableOutputs(outs, Codec) → lux.IsSortedTransferableOutputs(outs)
• lux.VerifyTx(fee, feeAsset, ins, outs, Codec) → lux.VerifyTx(fee, feeAsset, ins, outs)
• lux.GetAtomicUTXOs(sm, codec, ...) → lux.GetAtomicUTXOs(sm, ...)
• lux.NewAtomicUTXOManager(sm, codec) → lux.NewAtomicUTXOManager(sm)
• lux.NewUTXOState(db, codec, track) → lux.NewUTXOState(db, track)
• lux.NewMeteredUTXOState(db, codec, metrics, track) → lux.NewMeteredUTXOState(db, metrics, track)

needs the codec arg dropped. Plus every fx.Initialize callsite no longer needs vm.CodecRegistry() to do anything.

Order of operations

1. Define utxo/jsonutil/uint.go with Uint32/Uint64 JSON-string types.
2. Patch api.go to use jsonutil.
3. Patch flow_checker.go to inline a tiny errs collector.
4. Patch transferables.go to use wireSerializable.Bytes() as sort key.
5. Patch atomic_utxos.go to use wire.WrapUTXO(b).
6. Patch utxo_state.go to use utxo.WireBytes() / WrapUTXOBytes.
7. Patch every fx's vm.go to drop CodecRegistry() + Codec field.
8. Patch every fx's fx.go Initialize to drop the registration chain.
9. Patch every fx's tests to drop Codec: linearcodec.NewDefault() + the linearcodec import.
10. Build + test in tree.
11. go mod edit -droprequire=github.com/luxfi/codec + tidy.
12. Cascade through luxd consumer files.