chat-relayer Authentication

import crypto from "node:crypto";

const { publicKey, privateKey } = crypto.generateKeyPairSync("ed25519");
const rawPub = publicKey.export({ type: "spki", format: "der" }).slice(-32);
const delegatePubkeyHex = Buffer.from(rawPub).toString("hex");

function canonicalChatReq({ messages, model, owner_address, namespace }) {
  let s = "";
  for (const m of messages) s += `${m.role}:${m.content}\n`;
  s += `model:${model}\nowner:${owner_address}\nns:${namespace}`;
  return Buffer.from(s, "utf8");
}

function sign(bytes) {
  const sig = crypto.sign(null, bytes, privateKey);
  return Buffer.from(sig).toString("hex");
}

async function call(base, body) {
  const canonical = canonicalChatReq(body);
  const signature_hex = sign(canonical);
  const payload = { ...body, delegate_pubkey_hex: delegatePubkeyHex, signature_hex };
  const resp = await fetch(`${base}/v1/chat`, {
    method: "POST",
    headers: { "content-type": "application/json" },
    body: JSON.stringify(payload),
  });
  return resp.json();
}

user:Remember that my favorite color is teal and I'm building Pinaivu in Rust.
model:gemma4-e4b-128k:latest
owner:0xpersisttest1
ns:default

{
  "messages": [{ "role": "user", "content": "Remember that my favorite color is teal and I'm building Pinaivu in Rust." }],
  "model": "gemma4-e4b-128k:latest",
  "owner_address": "0xpersisttest1",
  "namespace": "default",
  "delegate_pubkey_hex": "79b5370a255aa5a8364510bf602be3b3970b4f2a2242617dc88e10804b53fe71",
  "signature_hex": "2c8cef80690bc2d865185f07c2de51602c1fff7825145cf102cbd5940ae9b8e376123de5f4db3cffdb2945b222d8ba4cb6575629034813ed241d57b3b9870d0b"
}

{
  "content": "I remember that your favorite color is teal and that you are building Pinaivu using Rust.",
  "session_id": "b7c0bee8-c01f-4392-acfb-0e1a333d386b",
  "session_key": "gavubc6GtzOCw2OEmp+U+YH680f+wXidfy5DJc2EUNc=",
  "request_id": "430bb3aa-2f1a-4e6f-80e0-cd8b8734ba23",
  "recalled_facts": [],
  "latency_ms": 3250
}