Chat-with-Tools 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_tools domain.

// AXON Chat-with-Tools scaffold — streaming dialogue with function-
// calling tools (web search, calculator, time API).
//
// Differs from `chat.axon` (no tools) and `chat_research.axon`
// (corpus-grounded): this scaffold lets the model invoke declared
// tools mid-conversation. The closed catalogue of tools is the
// agent's only external-call surface — strict-tool-mode optional.

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

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

type ChatRequest { req: Utterance }

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

persona ToolUsingAssistant {
    domain: ["general-assistance", "tool-orchestration"]
    tone: friendly
    confidence_threshold: 0.7
    cite_sources: true
}

context ChatContext {
    memory: session
    language: "en"
    depth: standard
    max_tokens: 4096
    temperature: 0.4
}

anchor BeHonestAboutToolFailures {
    require: source_citation
    confidence_floor: 0.6
    unknown_response: "A required tool returned an error — I cannot answer that confidently."
    on_violation: log
}

// ── Tools — closed catalogue ──────────────────────────────────────

tool WebSearch {
    provider:    http
    max_results: 5
    timeout:     10s
    effects:     <network, stream:drop_oldest>
}

tool Calculator {
    provider: native
    timeout:  500ms
    effects:  <pure>
}

tool TimeAPI {
    provider: native
    timeout:  2s
    effects:  <network>
}

// ── Streaming flow with tool-use surface ──────────────────────────

flow Chat(req: Utterance) -> Stream<Token> {
    step Respond {
        given: req
        apply: WebSearch
        ask: "Reply to the user; invoke WebSearch, Calculator, or TimeAPI when their output would ground the reply. Stream tokens as you go."
        output: Stream<Token>
    }
    return Respond.output
}

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

axonendpoint ChatToolsAPI {
    method:    post
    path:      "/v1/chat/tools"
    body:      ChatRequest
    execute:   Chat
    output:    Stream<Token>
    backend:   auto
    transport: sse(axon)
    retries:   0
    timeout:   90s public: true
}