Signed record

Save a record with an attestation signature attached.

Trigger: xrpc.procedure:<nsid>. Needs: happyview-record, happyview-atproto.

Lua

local time = require("internal.time")
local record = require("happyview.record")
local atproto = require("happyview.atproto")

function handle(input, ctx)
  local body = { text = input.text, createdAt = time.to_iso8601(time.now()) }

  local ok, sig = pcall(atproto.sign, body)
  if ok then
    body.signature = sig
  end

  local ref = record.create(ctx.collection, body)
  return { uri = ref.uri, cid = ref.cid, signature = body.signature }
end

JavaScript

import time from "internal.time";
import record from "happyview.record";
import atproto from "happyview.atproto";

export default async function handle(input, ctx) {
  const body = { text: input.text, createdAt: time.to_iso8601(time.now()) };

  try {
    body.signature = await atproto.sign(body);
  } catch {
    // No signature: the record is saved without one.
  }

  const ref = await record.create(ctx.collection, body);
  return { uri: ref.uri, cid: ref.cid, signature: body.signature };
}

TypeScript

import time from "internal.time";
import record from "happyview.record";
import atproto from "happyview.atproto";

export default async function handle(input: { text: string }, ctx: { collection: string }) {
  const body: Record<string, unknown> = {
    text: input.text,
    createdAt: time.to_iso8601(time.now()),
  };

  try {
    body.signature = await atproto.sign(body);
  } catch {
    // No signature: the record is saved without one.
  }

  const ref = await record.create(ctx.collection, body);
  return { uri: ref.uri, cid: ref.cid, signature: body.signature };
}

How it works

1. Build the record body.
2. Sign it with sign on happyview.atproto. The pcall (Lua) or try/catch (JavaScript and TypeScript) lets the script work without a signer configured, where sign raises NO_SIGNER. Signing also needs a caller, which a procedure always has.
3. Attach the signature to the body as body.signature, then save the record with record.create. Declare signature in the record lexicon, so apps reading the record know the field exists.
4. Return the signature alongside the URI.

The signature’s $type defaults to games.gamesgamesgamesgames.attestation. Set ATTESTATION_SIG_TYPE to use another type.

Usage

The DPoP proof is signed per request; an app built on the HappyView SDK gets this from its session.

TypeScript

const response = await fetch("http://127.0.0.1:3000/xrpc/xyz.example.createPost", {
  method: "POST",
  headers: {
    "X-Client-Key": CLIENT_KEY,
    Authorization: `DPoP ${ACCESS_TOKEN}`,
    DPoP: DPOP_PROOF,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({ text: "Hello world" }),
});
const data = await response.json();

JavaScript

const response = await fetch("http://127.0.0.1:3000/xrpc/xyz.example.createPost", {
  method: "POST",
  headers: {
    "X-Client-Key": CLIENT_KEY,
    Authorization: `DPoP ${ACCESS_TOKEN}`,
    DPoP: DPOP_PROOF,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({ text: "Hello world" }),
});
const data = await response.json();

Rust

let response = client
    .post("http://127.0.0.1:3000/xrpc/xyz.example.createPost")
    .header("X-Client-Key", client_key)
    .header("Authorization", format!("DPoP {access_token}"))
    .header("DPoP", dpop_proof)
    .json(&serde_json::json!({ "text": "Hello world" }))
    .send()
    .await?;

Go

body := `{ "text": "Hello world" }`
req, _ := http.NewRequest("POST", "http://127.0.0.1:3000/xrpc/xyz.example.createPost", bytes.NewBufferString(body))
req.Header.Set("X-Client-Key", clientKey)
req.Header.Set("Authorization", "DPoP "+accessToken)
req.Header.Set("DPoP", dpopProof)
req.Header.Set("Content-Type", "application/json")
resp, err := http.DefaultClient.Do(req)

cURL

curl -X POST http://127.0.0.1:3000/xrpc/xyz.example.createPost \
  -H "X-Client-Key: $CLIENT_KEY" \
  -H "Authorization: DPoP $ACCESS_TOKEN" \
  -H "DPoP: $DPOP_PROOF" \
  -H "Content-Type: application/json" \
  -d '{ "text": "Hello world" }'

{
  "uri": "at://did:plc:abc/xyz.example.post/3abc123",
  "cid": "bafyrei...",
  "signature": {
    "$type": "games.gamesgamesgamesgames.attestation",
    "key": "did:web:happyview.example.com#attestation",
    "signature": { "$bytes": "..." }
  }
}

Use case

An attestation signature lets an app verify that a record was processed by your instance, for contributions, moderation decisions or data shared between instances. The signature covers both the record content and the author’s DID, so it can’t be replayed across users, and changing the record invalidates it.

See Attestation signing for setup and configuration, or Verify a signed record for the read side.