Flow that uses a tool with a declared backend

Primitives used: persona · flow · step · tool

// A step invokes a named tool via `apply:` — running the tool as
// that step's backend. The tool declares its provider + effects +
// timeout once; every step that uses it inherits those constraints.
//
// This is ONE of two canonical tool surfaces. The other is the
// flow-level `use <Tool>(k = v, …)` dispatch (typed, schema-
// validated structured args, real HTTP/MCP dispatch) — see
// `axon://primitives/tool`. Use `apply:` to run a tool as a step's
// backend; use `use <Tool>(…)` for an explicit, typed call whose
// result a later step consumes.

persona Translator {
    domain: ["translation"]
    tone: precise
    confidence_threshold: 0.9
    cite_sources: false
}

tool TranslationBackend {
    // LLM-routed: the tool IS the model. No `provider:` (v2.69.0).
    effects:  <network>
    timeout:  30s
}

type Input  { text: String, target_lang: String }
type Output { text: String }

flow Translate(req: Input) -> Output {
    step Render {
        given: req
        apply: TranslationBackend
        ask: "Translate the input text into the target language."
        output: Output
    }
    return Render.output
}