Tiny functions, composed by anyone , including the agents in your stack

import fn from "@hostfunc/sdk";

// HTTP endpoint. POST { "name": "Ada" } — or GET ?name=Ada
export async function main(input: { name?: string }) {
  const name = input.name?.trim() || "world";
  fn.log("info", "hello.invoked", { name });

  return {
    message: `hello, ${name}`,
    invokedAt: new Date().toISOString(),
  };
}

import fn from "@hostfunc/sdk";
import { askAi } from "@hostfunc/sdk/ai";

// HTTP endpoint. POST { "text": "...", "sentences": 3 }
export async function main(input: { text?: string; sentences?: number }) {
  const text = input.text?.trim();
  if (!text) {
    return { summary: "", note: "Provide 'text' to summarize." };
  }

  const sentences = Math.min(Math.max(input.sentences ?? 3, 1), 8);
  const answer = await askAi(text, {
    system: `Summarize the user's text in at most ${sentences} sentences. Be factual and concise.`,
    maxTokens: 400,
  });

  fn.log("info", "summary.created", { inputChars: text.length });
  return { summary: answer.text, model: answer.model, usage: answer.usage };
}

import fn, { secret } from "@hostfunc/sdk";

// HTTP endpoint. POST { "text": "Deploy finished", "title": "CI", "level": "info" }
// Secret: SLACK_WEBHOOK_URL — a Slack incoming-webhook URL.
export async function main(input: { text?: string; title?: string; level?: string }) {
  if (!input.text) {
    throw new Error("Provide 'text' to send to Slack.");
  }

  const emoji =
    input.level === "error"
      ? ":red_circle:"
      : input.level === "warn"
        ? ":warning:"
        : ":white_check_mark:";

  const webhookUrl = await secret.getRequired("SLACK_WEBHOOK_URL");
  const res = await fetch(webhookUrl, {
    method: "POST",
    headers: { "content-type": "application/json" },
    body: JSON.stringify({
      text: `${emoji} *${input.title ?? "Notification"}*: ${input.text}`,
    }),
  });

  fn.log(res.ok ? "info" : "error", "slack.notified", { status: res.status });
  return { ok: res.ok, status: res.status };
}

import fn from "@hostfunc/sdk";

// HTTP endpoint. Point any webhook here to inspect its payload.
export async function main(input: Record<string, unknown>) {
  const keys = Object.keys(input ?? {});
  fn.log("info", "webhook.received", { keyCount: keys.length, keys });

  return {
    ok: true,
    receivedAt: new Date().toISOString(),
    payloadKeys: keys,
    payload: input,
  };
}