Hi Thomas, 
I’ve been looking through your BTSL playground source code. To make this 
work seamlessly with the Blind Relay reference implementation (Signing 
Room), it would be great if the BTSL parser and validator were available as 
a standalone, versioned NPM package.

If we had an @btsl/validator package that was environment-agnostic (no 
internal fetch calls to Blockstream, just pure PSBT/Schema validation and 
minimal dependencies), I could potentially integrate it directly into the 
Signing Room client. This would allow 'Signing Room' to automatically 
detect an attached schema, run the ASSERT logic locally, and provide the 
user with a 'Verified by BTSL' green-check before they sign.

The STATE_SYNC payload could be modified to something like this to pass a 
schema and type:

  { 
     "type": "STATE_SYNC", 
     "encryptedPsbt": "base64_encrypted_psbt", 
     "encryptedValidationSchema": "base64_encrypted_btsl_string",  // 
Optional 
     "schemaType": "BTSL_V1", // Optional: Identifies the language Or 
Version ... 
}  

Let me know your thoughts,

All the best
Sean Carlin



On Thursday, 26 March 2026 at 14:21:41 UTC Thomas Suau wrote:

> Hello, 
> The transport layer problem is well addressed here. The complementary 
> piece — ensuring signers can independently validate transaction invariants 
> before signing, regardless of how the PSBT was relayed — is what I've been 
> exploring with BTSL: 
> https://delvingbitcoin.org/t/btsl-bitcoin-transaction-schema-language-a-declarative-validation-schema-for-psbt-workflows/2338
>
> Best regards, 
> Thomas Suau
>
> Le mercredi 25 mars 2026 à 13:21:39 UTC+1, Sean Carlin a écrit :
>
>> Hi everyone,
>>
>> I'd like to propose a new BIP for real-time, trust-minimized coordination 
>> of multi-signature PSBTs.
>>
>> The Problem
>> Coordinating N-of-M Bitcoin transactions currently forces users into a 
>> binary choice:
>> - Manual out-of-band transfers (USB drives, secure messengers) that 
>> preserve privacy but introduce high friction and error risk, or
>> - Stateful coordination servers that offer good UX but act as privacy 
>> honeypots, logging metadata, signer relationships, and often storing PSBTs 
>> on disk.
>>
>> The Proposal: Blind Relay
>> This BIP introduces a "Blind Relay" - an ephemeral, stateless, 
>> zero-knowledge WebSocket relay. All payloads are encrypted client-side with 
>> AES-GCM-256, with decryption keys held exclusively in client-side URL 
>> fragments (never sent to the server). The relay operates entirely in RAM 
>> with a strict 24-hour TTL and self-destructs upon completion, providing 
>> real-time coordination without persistent metadata or disk storage.
>>
>> A reference implementation has been running in production for three 
>> months, successfully facilitating real multisig ceremonies.
>>
>> *Links*
>> - BIP Draft: 
>> https://github.com/scarlin90/bip-stateless-psbt-coordination/blob/main/bip-draft.md
>> - Source Code: https://github.com/scarlin90/signingroom
>> - Live Client: https://signingroom.io
>> - Related Research Paper: https://arxiv.org/abs/2601.17875
>>
>> I look forward to your technical feedback - especially on the 
>> specification, security model, edge cases, and any suggested improvements.
>>
>> Best regards,
>> Sean Carlin
>
>

-- 
You received this message because you are subscribed to the Google Groups "Bitcoin Development Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to bitcoindev+unsubscribe@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/bitcoindev/e501ab92-6911-4437-ac06-d7f547c2190dn%40googlegroups.com.