ruvnet/RuView · error · TypeError

prompt must be a non-empty string

Error message

prompt must be a non-empty string

What it means

runCodex (harness/ruview/src/hosts/codex.js) is the host adapter that spawns `codex exec -` with the prompt on stdin. It requires a string prompt with non-whitespace content; empty, null, or non-string prompts throw before the repo-trust check or process spawn.

Source

Thrown at harness/ruview/src/hosts/codex.js:12

// SPDX-License-Identifier: MIT
import { runProcess } from '../process-runner.js';
import { assertTrustedRuViewRepo } from '../repo-trust.js';
export function buildCodexArgs(root, { write = false } = {}) {
  return ['exec', '-', '-C', root, '--sandbox', write ? 'workspace-write' : 'read-only',
    '--ephemeral', '--json', '--strict-config', '--ignore-user-config', '--ignore-rules'];
}
export async function runCodex({
  prompt, repoRoot, trustedRoot = repoRoot, allowWrite = false, confirm = false,
  command = 'codex', commandArgs = [], ...runOptions
}) {
  if (typeof prompt !== 'string' || !prompt.trim()) throw new TypeError('prompt must be a non-empty string');
  const root = assertTrustedRuViewRepo(repoRoot, { trustedRoot });
  const write = allowWrite === true && confirm === true;
  return runProcess(command, [...commandArgs, ...buildCodexArgs(root, { write })], { ...runOptions, cwd: root, input: prompt });
}
export default Object.freeze({ name: 'codex', run: runCodex, buildArgs: buildCodexArgs });

View on GitHub (pinned to 4685618388)

Solutions

1. Validate the prompt before calling: if (typeof prompt !== 'string' || !prompt.trim()) fail early with context.
2. Read the prompt file first and assert non-empty content.
3. Pass a concrete task string: runCodex({ prompt: 'Map startup restore and cite files', repoRoot }).

Example fix

// before
runCodex({ prompt: readFileSync(promptFile, 'utf8'), repoRoot }) // file was empty
// after
const prompt = readFileSync(promptFile, 'utf8').trim();
if (!prompt) throw new Error(`prompt file is empty: ${promptFile}`);
runCodex({ prompt, repoRoot });

const prompt = typeof rawPrompt === 'string' ? rawPrompt.trim() : '';
if (!prompt) throw new Error('codex host requires a non-empty prompt');
runCodex({ prompt, repoRoot });

function isNonEmptyPrompt(v) {
  return typeof v === 'string' && v.trim().length > 0;
}

try {
  await runCodex({ prompt, repoRoot });
} catch (e) {
  if (e instanceof TypeError && e.message === 'prompt must be a non-empty string') {
    throw new Error('codex delegation aborted: prompt was empty');
  }
  throw e;
}

When it happens

Trigger: runCodex({}) (prompt undefined), runCodex({ prompt: '' }), runCodex({ prompt: '\n ' }), or reading the prompt from an empty file/stdin before passing it through.

Common situations: Empty stdin when the agent-run command is scripted (`agent run --prompt-file empty.txt`); template builders returning blank strings; prompt sent as an object or buffer instead of a string.

Related errors

• prompt must be a non-empty string
• Unsupported host: ${name}
• guidance input must be an object
• guidance options must be an object
• guidance topic must be a string

AI-assisted analysis of ruvnet/RuView@4685618388 (2026-08-16). Data as JSON: /api/errors/da7acaf24af2313f. Report an issue: GitHub.