pds-message-poc#

interactive browser demo of PDS-to-PDS message passing.

inspired by jacob.gold's post about PDSes having incoming message queues for DMs.

live demo: sites.wisp.place/zzstoatzz.io/pds-message-poc

architecture#

this demo uses a real PDS deployment:

• pds.js fork deployed to Cloudflare Workers at pds-message-demo.nate-8fe.workers.dev
• real DIDs registered with plc.directory
• real service auth - JWTs signed server-side via com.atproto.server.getServiceAuth
• real signature verification - recipient PDS resolves sender DID via PLC to get public key

┌─────────────────┐                              ┌─────────────────┐
│   Browser       │                              │   PDS Worker    │
│   (demo UI)     │                              │   (Cloudflare)  │
├─────────────────┤                              ├─────────────────┤
│                 │  1. createSession(bob)       │                 │
│                 │ ────────────────────────────>│  bob's DO       │
│                 │  ← accessJwt                 │                 │
│                 │                              │                 │
│                 │  2. getServiceAuth(aud=alice)│                 │
│                 │ ────────────────────────────>│  signs JWT      │
│                 │  ← service JWT               │  server-side    │
│                 │                              │                 │
│                 │  3. inbox.send + JWT         │                 │
│                 │ ────────────────────────────>│  alice's DO:    │
│                 │                              │  - resolve DID  │
│                 │                              │  - verify sig   │
│                 │                              │  - check spam   │
│                 │                              │  - deliver/queue│
│                 │  ← {status: ...}             │                 │
└─────────────────┘                              └─────────────────┘
                          │
                          ▼
                  ┌───────────────┐
                  │ plc.directory │
                  │ (DID → pubkey)│
                  └───────────────┘

run locally#

git submodule update --init
npm install
npm run dev

usage#

• type a message, select sender → recipient
• send - initiates message (first message creates a request)
• accept - recipient accepts pending request, messages flow freely
• reject - recipient rejects request and blocks sender
• spam - labeler marks sender as spam (rejected by all PDSes)

invitation flow#

first contact requires acceptance (like DM requests):

1. bob sends message to alice → creates request (message held)
2. alice sees request in her "requests" section
3. alice clicks accept → original message delivered, bob now accepted
4. subsequent messages from bob deliver immediately (subject to rate limits)

alternatively:

• alice clicks reject → request deleted, bob blocked permanently

what's real#

what's demonstrated#

what's simplified#

pds.js modifications#

our fork adds:

• xyz.fake.inbox.* XRPC endpoints (send, list, listRequests, accept, reject)
• inbox tables in SQLite schema
• PLC resolution for DID → public key during JWT verification
• com.atproto.server.getServiceAuth for server-side JWT signing

prior art#

• AT Protocol and SMTP - ngerakines on PDS as crypto service
• bourbon protocol - invitation-based messaging
• How Streamplace Works - embedded PDS pattern

references#

• jacob.gold's thread
• pds.js - cloudflare workers PDS
• official PDS
• service auth
• AT Protocol specs