@av-pi-studio/protocol

Shared wire schemas, binary frame codecs, and capability flags for Pi-Studio. This package is the single source of truth for everything that crosses the WebSocket between the daemon and any client (CLI, web, mobile, desktop).

It is a zero-runtime-workspace-dependency library — the only external dependency is zod — so it can be imported by browser and React Native clients as freely as by the Node.js daemon.

Install

npm install @av-pi-studio/protocol

What's in here

• JSON wire schemas (messages.ts) — every message type that can appear on the WebSocket, as Zod schemas plus their inferred TypeScript types: the hello/status handshake, RPC requests/responses, broadcasts (agent_update, agent_stream, …), and the top-level envelope union that wraps them all.
• Binary frame codecs (binary-frames/) — encode/decode functions for the two binary wire formats: terminal I/O ([opcode][slot][payload]) and chunked file transfer. Both use Uint8Array, never Buffer, so they run unchanged in a browser.
• Client capability flags (client-capabilities.ts) — CLIENT_CAPS (what a client can advertise in hello.capabilities) and SERVER_FEATURES (what the daemon advertises in server_info.features), plus a supports() helper.
• Endpoint parsing (endpoint.ts) — turns a daemon target string (host:port, ws://…, relay://…) into a structured EndpointDescriptor.
• Provider manifest types (provider-manifest.ts) — UI-facing scaffolding for describing providers/modes (labels, color tiers, capability flags).

Usage

import {
  helloSchema,
  agentStreamEventSchema,
  encodeTerminalFrame,
  decodeTerminalFrame,
  parseEndpoint,
  rpcName,
} from "@av-pi-studio/protocol";

// Validate + parse an inbound message
const hello = helloSchema.parse(rawJson);

// Build a canonical dotted RPC name
const name = rpcName("agent", "permission", "respond", "request");
// → "agent.permission.respond.request"

// Parse a daemon connection target
const endpoint = parseEndpoint("workstation.local:6767");
// → { kind: "direct", host: "workstation.local", port: 6767, ssl: false, raw: "…" }

Every exported schema has a paired TypeScript type (XSchema / X), inferred with z.infer<> — import whichever you need.

Design rules

These are enforced by convention and by the package's own tests, not by tooling:

• Append-only. Fields are only ever added, and only as optional. Nothing is ever removed, narrowed, or given a new discriminant value. This is what lets an older daemon load data written by a newer one (and vice versa) without a migration step.
• Schema passthrough. Most schemas use Zod's .passthrough(), so unknown fields from a newer protocol version survive a round-trip through an older decoder instead of being stripped or rejected.
• Zero workspace imports. This package never imports from another @av-pi-studio/* package — it has to stay usable standalone by any future client, including ones that don't otherwise depend on the rest of the monorepo.
• Cross-platform binary codecs. The binary frame encode/decode functions only use Uint8Array — no Node-only APIs — so they work identically in Node, the browser, and React Native.
• Dotted RPC names. New RPCs are named via rpcName(domain, sub, op, dir) → "domain.provider.operation.direction" (e.g. agent.permission.respond.request). Legacy flat names are still accepted on the wire via aliases, but never generated by new code.

Adding a new wire message type

1. Define the Zod schema (and its inferred type) in messages.ts or a new sibling file.
2. Add it to the sessionMessageSchema discriminated union.
3. Export it from index.ts.
4. Add a round-trip test (messages.envelopes.test.ts or a new *.test.ts).
5. Register the corresponding handler in the daemon's HandlerRegistry (@av-pi-studio/server).

Development

npm run build       # tsc -b
npx vitest run packages/protocol

Tests are Vitest and live alongside their source files as *.test.ts.