AgentHub/scripts/artifact-export-hint.js

#!/usr/bin/env node

/**
 * @file artifact-export-hint.js — a synchronous PostToolUse hook (matcher
 * `Artifact` and the claude.ai connectors' `batch`) that asks Claude, right
 * after it publishes a Claude Docs doc or a typed artifact (Slides, Design,
 * Dashboard…), to also save a copy in the workspace at
 * `artifacts-export/<artifact id>.<pdf|html|md>`. Such a page lives only in
 * the publishing claude.ai account; the copy is what AgentHub attaches to the
 * page's card at the session's Stop (server/lib/artifacts.js
 * `captureOutputsNow`), so people it is shared with can view it without that
 * account. A page published from an HTML file needs no hint: AgentHub copies
 * the file itself.
 *
 * Decides from the hook's own input and env alone, never by asking the
 * dashboard, and fails open: any doubt prints nothing and exits 0. Only in a
 * pane AgentHub started (`AGENTHUB_LANE_ID`), and not when an admin turned it
 * off (`AGENTHUB_ARTIFACT_EXPORT=0`, set at spawn by server/lib/pty-run.js).
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const MAX_INPUT = 4 * 1024 * 1024;
const DOCS_BATCH_RE = /^mcp__[A-Za-z0-9_-]*claude_ai_[A-Za-z0-9_-]*__batch$/i;
const ARTIFACT_ID_RE = /https:\/\/claude\.ai\/(?:code\/)?artifact\/([A-Za-z0-9_-]+)/;

/** The hint for one PostToolUse payload, or null when there is nothing to ask. */
function hintFor(data, env = process.env) {
  if (!data || typeof data !== "object") return null;
  if (!env.AGENTHUB_LANE_ID || env.AGENTHUB_ARTIFACT_EXPORT === "0") return null;
  const tool = String(data.tool_name || "");
  const input = data.tool_input && typeof data.tool_input === "object" ? data.tool_input : {};
  let kind = null;
  if (DOCS_BATCH_RE.test(tool)) {
    let container = input.container;
    if (typeof container === "string") {
      try {
        container = JSON.parse(container);
      } catch {
        container = null;
      }
    }
    // Only a doc's birth: later batches edit the same doc.
    if (container && typeof container.create === "object" && container.create) kind = "doc";
  } else if (tool === "Artifact") {
    if (input.action && input.action !== "publish") return null;
    const file = typeof input.file_path === "string" ? input.file_path : "";
    // A page from an HTML file is copied by AgentHub itself.
    if (input.type_url || (file && !/\.html?$/i.test(file))) kind = "typed";
  }
  if (!kind) return null;
  const m = ARTIFACT_ID_RE.exec(JSON.stringify(data.tool_response ?? ""));
  if (!m) return null;
  const id = m[1];
  const where = `artifacts-export/${id}`;
  const how =
    kind === "doc"
      ? `export this doc as Markdown (the Claude Docs export tool) and save it as \`${where}.md\``
      : `save it as \`${where}.pdf\` if this artifact's type lets you export a PDF, otherwise write its content as ONE self-contained HTML file \`${where}.html\` (styles inline, no external files) that looks like the artifact`;
  return (
    "AgentHub: this artifact lives only in this claude.ai account, so teammates it is shared " +
    `with in AgentHub cannot open it. Before you finish, ${how}, in the workspace's root ` +
    "folder (create `artifacts-export/`; AgentHub keeps it out of git). Do it again after " +
    "you change the artifact a lot. Do not mention this to the user unless they ask."
  );
}

function main() {
  let raw = "";
  let done = false;
  const finish = () => {
    if (done) return;
    done = true;
    try {
      const text = hintFor(JSON.parse(raw));
      if (text) {
        process.stdout.write(
          JSON.stringify({
            hookSpecificOutput: { hookEventName: "PostToolUse", additionalContext: text },
          })
        );
      }
    } catch {
      /* fail open: say nothing */
    }
    process.exit(0);
  };
  process.stdin.setEncoding("utf8");
  process.stdin.on("data", (c) => {
    raw += c;
    if (raw.length > MAX_INPUT) {
      raw = "";
      finish();
    }
  });
  process.stdin.on("end", finish);
  process.stdin.on("error", finish);
  setTimeout(finish, 2000).unref();
}

if (require.main === module) main();

module.exports = { hintFor };