@sema-agent/core/dist/brain/routing.js

Stateless, task-oriented AI agent core

import { createAssistantMessageEventStream, } from "../internal/llm.js";
import { ZERO_USAGE } from "./errors.js";
function errorMessage(model, text) {
    return {
        role: "assistant",
        content: [{ type: "text", text: "" }],
        api: model.api,
        provider: model.provider,
        model: model.id,
        stopReason: "error",
        errorMessage: text,
        usage: ZERO_USAGE,
        timestamp: Date.now(),
    };
}
export function createRoutingBrain(routes, opts = {}) {
    const by = opts.by ?? "provider";
    const resolveTarget = (model) => {
        const key = by === "api" ? model.api : model.provider;
        const routed = Object.hasOwn(routes, key) ? routes[key] : undefined;
        const matched = routed !== null && typeof routed === "object" && typeof routed.stream === "function"
            ? routed
            : undefined;
        return matched ?? opts.fallback;
    };
    const stream = (model, context, options) => {
        const key = by === "api" ? model.api : model.provider;
        const target = resolveTarget(model);
        if (!target) {
            const out = createAssistantMessageEventStream();
            out.push({
                type: "error",
                reason: "error",
                error: errorMessage(model, `createRoutingBrain: no brain for ${by}="${key}"`),
            });
            return out;
        }
        return target.stream(model, context, options);
    };
    const adjudicateRoute = (model, perModelAuth) => resolveTarget(model)?.adjudicateRoute?.(model, perModelAuth);
    return { stream, adjudicateRoute };
}