pike/glyph Public Public: anyone can read this; nobody can change it.

/**

 * Running Claude Code to draw. The forge puts `claude` on the PATH every app

 * inherits; it signs in with the token in CLAUDE_CODE_OAUTH_TOKEN and keeps

 * its state under the app's data directory, the one place an app may write.

 * It is started with no tools at all — drawing is words in, words out — and

 * with the environment named here and nothing else, so no other secret of

 * the app reaches it.

 *

 * On the forge an app runs in a cell whose only way out is the forge's

 * egress proxy, named in HTTPS_PROXY; without it Claude Code finds no DNS.

 * So the proxy variables go through, and the API's hosts are declared in

 * forge.json `egress`. (Learned on apps/radar.)

 */

import { mkdirSync } from "node:fs";

import { join } from "node:path";

/** Claude Code with these arguments, this prompt on stdin, its stdout back. */

export type RunClaude = (args: readonly string[], prompt: string) => Promise<string>;

export const MODEL = "claude-opus-5-5";

const TIMEOUT_MS = 5 * 60 * 1000;

/** Passed through when set: the cell's way out, and a CA the machine may add. */

const PASSED = [

  "HTTPS_PROXY", "https_proxy", "HTTP_PROXY", "http_proxy", "NO_PROXY", "no_proxy", "NODE_EXTRA_CA_CERTS",

] as const;

/** The arguments for one drawing: print mode, one JSON answer, no tools, no session kept. */

export function drawArgs(model = MODEL): string[] {

  return [

    "-p", "--output-format", "json",

    "--tools", "", "--strict-mcp-config", "--no-session-persistence",

    "--disable-slash-commands", "--model", model,

  ];

}

/** The whole environment Claude Code is started with. */

export function claudeEnv(

  token: string,

  config: string,

  from: Readonly<Record<string, string | undefined>> = process.env,

): Record<string, string> {

  const env: Record<string, string> = {

    PATH: from.PATH ?? "/usr/local/bin:/usr/bin:/bin",

    HOME: from.HOME ?? config,

    LANG: from.LANG ?? "C.UTF-8",

    CLAUDE_CONFIG_DIR: config,

    CLAUDE_CODE_OAUTH_TOKEN: token,

    // No telemetry, error reports or self-updates: hosts the cell does not declare.

    CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC: "1",

  };

  for (const name of PASSED) {

    const value = from[name];

    if (value) env[name] = value;

  }

  return env;

}

export function claudeRunner(token: string, dataDir: string, timeoutMs = TIMEOUT_MS): RunClaude {

  return async (args, prompt) => {

    const config = join(dataDir, "claude");

    mkdirSync(config, { recursive: true });

    const env = claudeEnv(token, config);

    if (Bun.which("claude", { PATH: env.PATH ?? "" }) === null)

      throw new Error("claude is not on the PATH here");

    const proc = Bun.spawn(["claude", ...args], {

      env,

      cwd: config,

      stdin: new Blob([prompt]),

      stdout: "pipe",

      stderr: "pipe",

    });

    const timer = setTimeout(() => proc.kill(), timeoutMs);

    try {

      const [out, err, code] = await Promise.all([

        new Response(proc.stdout).text(),

        new Response(proc.stderr).text(),

        proc.exited,

      ]);

      if (code !== 0 && !out.includes('"result"'))

        throw new Error(`claude exited ${code}: ${err.trim().slice(0, 200)}`);

      return out;

    } finally {

      clearTimeout(timer);

    }

  };

}

/** The model's final text from `--output-format json`, or why there is none. */

export function resultText(stdout: string): { ok: true; text: string } | { ok: false; why: string } {

  let parsed: unknown;

  try {

    parsed = JSON.parse(stdout.trim().split("\n").at(-1) ?? "");

  } catch {

    return { ok: false, why: "Claude's answer was not JSON." };

  }

  const r = (parsed ?? {}) as Record<string, unknown>;

  if (r.is_error === true || typeof r.result !== "string")

    return { ok: false, why: `Claude stopped: ${String(r.result ?? r.subtype ?? "no result").slice(0, 200)}` };

  return { ok: true, text: r.result };

}