Chat scaffold

A complete program, not a fragment: it compiles as written. Copy it, rename the placeholder identifiers to your domain, and run axon check — the compiler will tell you what your renaming broke. An MCP client can also generate it through the axon.compose tool by naming the chat domain.

// AXON Chat scaffold — streaming dialogue over a session-typed socket.
//
// Produces a turn-taking chat protocol with credit-refined
// backpressure, a token-by-token streaming flow, and a WebSocket
// transport bound to the session by the v2.3.0 duality rules.

// ── Types ─────────────────────────────────────────────────────────

type Utterance { text: String }
type Token     { piece: String }

// The endpoint's body type — the chat prompt arrives as a single
// utterance bound to the flow's `req` parameter.
type ChatRequest { req: Utterance }

// ── Identity + grounding ──────────────────────────────────────────

persona ConversationalAssistant {
    domain: ["chat", "general-conversation"]
    tone: friendly
    confidence_threshold: 0.6
    cite_sources: false
}

context ChatContext {
    memory: session
    language: "en"
    depth: standard
    max_tokens: 4096
    temperature: 0.7
}

anchor StayOnTopic {
    require: source_citation
    confidence_floor: 0.5
    unknown_response: "I'm not sure — could you rephrase or add more detail?"
    on_violation: log
}

// ── Tool — declares the stream backpressure policy ────────────────
//
// Any flow whose signature uses `Stream<T>` must be reachable from a
// tool that declares a `stream:<policy>` effect. Valid policies:
// drop_oldest | degrade_quality | pause_upstream | fail.

tool ChatBackend {
    // LLM-routed: the tool IS the model. No `provider:` (v2.69.0). `openai` was not a real provider slug.
    effects:  <network, stream:drop_oldest>
    timeout:  60s
}

// ── Streaming flow ────────────────────────────────────────────────

flow Chat(req: Utterance) -> Stream<Token> {
    step Generate {
        given: req
        apply: ChatBackend          // reaches a tool with stream:<policy> effect
        ask: "Reply to the user, one token at a time."
        output: Stream<Token>
    }
    return Generate.output
}

// ── Streaming HTTP boundary ───────────────────────────────────────

axonendpoint ChatAPI {
    method:      post
    path:        "/v1/chat"
    body:        ChatRequest
    execute:     Chat
    output:      Stream<Token>
    backend:     auto
    transport:   sse(axon)
    retries:     0
    timeout:     60s public: true
}