Address derivation mismatch between TypeScript and Rust SDKs

[LastDegenBtc]

Issue: Address derivation mismatch between TypeScript and Rust SDKs

Summary

The Rust SDK derives a different Ark address than the TypeScript SDK for the same private key, causing VTXOs created via Arkade wallet to be invisible to Rust SDK users.

Environment

• Rust SDK: arkade-os/rust-sdk (latest)
• Network: Mainnet (arkade.computer)

Reproduction

Same nsec key produces different addresses:

SDK	Address suffix (vtxo_tap_key portion)
TypeScript (Arkade wallet)	...5y3nqpqwrzefat672devsgcpv8tgjqf6xmfp8ge4c77ge4x44ae4t...
Rust SDK	...4u2786dhx27fg7fssc9ynkl6j523yaylg34hmagkdch2sqjn0sew...

Both share the same server pubkey prefix, confirming the secret key is parsed correctly.

Root Cause Analysis

The x-only pubkey derivation works correctly. The difference is in the taproot tree construction that produces the vtxo_tap_key:

• Raw x-only pubkey: 16608a14cda9163faeb909c6f2ad05c634cee7935b57f2f9f662a6db80f78b68
• TypeScript vtxo_tap_key: 12330040e18b29eaf5e5372c8230161d689013a36d213a335c7bc8cd4d5af735
• Rust vtxo_tap_key: f15e3e9b732bc947930860a49dbfa951512749f446b7df5166e2ea802537c32e

The taproot tweak/tree structure differs between implementations.

Impact

• VTXOs created via Arkade wallet cannot be queried or spent using Rust SDK
• Users importing nsec into Rust applications see 0 balance

Workaround

Query VTXOs using the Arkade-provided address directly via get_vtxos(&[ark_address]) instead of relying on local address derivation.

[louisinger]

unit test fixtures for taproot key computation followed by go and ts SDKs : https://github.com/arkade-os/ts-sdk/blob/master/test%2Ffixtures%2Fvtxoscript.json

we should add the same fixture to rust SDK

[LastDegenBtc]

indeed , we couldn't make a derivation work in rust. From your info we tried to fork the sdk and use the table but it's not enough .
for now we did a wrapper using the ts sdk , wich i know to work well. When this is resolved we will re integrate the rust one :)

[luckysori]

Thanks for the report, @LastDegenBtc.

I'm curious to know how you imported the Arkade Nsec into the Rust SDK. Were you using ark-core or ark-client? What API did you call? If you can show us some Rust code that would be really useful.

We are currently working on #120 which should in theory help with something like this.