nanocoai/nanoclaw · error · StdinJsonInputError

--stdin-json key "${key}" is also supplied on argv

Error message

--stdin-json key "${key}" is also supplied on argv

What it means

A key present in --stdin-json is also present as a direct argv flag; to avoid ambiguity about which value wins, the CLI rejects exact duplicates.

Source

Thrown at src/cli/stdin-json.ts:116

 */
function assertNoKeyConflicts(
  stdinArgs: Readonly<Record<string, unknown>>,
  argvArgs: Readonly<Record<string, unknown>>,
): void {
  const argvKeysByCanonical = new Map<string, string>();
  for (const key of Object.keys(argvArgs)) {
    const canonical = canonicalArgKey(key);
    if (!argvKeysByCanonical.has(canonical)) argvKeysByCanonical.set(canonical, key);
  }

  const stdinKeysByCanonical = new Map<string, string>();
  for (const key of Object.keys(stdinArgs)) {
    if (key === '__proto__') {
      throw new StdinJsonInputError('--stdin-json key "__proto__" is not allowed');
    }

    if (Object.prototype.hasOwnProperty.call(argvArgs, key)) {
      throw new StdinJsonInputError(`--stdin-json key "${key}" is also supplied on argv`);
    }

    const canonical = canonicalArgKey(key);
    const argvKey = argvKeysByCanonical.get(canonical);
    if (argvKey !== undefined) {
      throw new StdinJsonInputError(
        `--stdin-json key "${key}" conflicts with argv key "${argvKey}" after CLI key normalization`,
      );
    }

    const priorStdinKey = stdinKeysByCanonical.get(canonical);
    if (priorStdinKey !== undefined) {
      throw new StdinJsonInputError(
        `--stdin-json keys "${priorStdinKey}" and "${key}" conflict after CLI key normalization`,
      );
    }
    stdinKeysByCanonical.set(canonical, key);
  }

View on GitHub (pinned to 294ef2aee8)

Solutions

1. Remove the duplicate: keep each key either in argv or in stdin JSON, not both

Example fix

# before
ncl groups update --id g1 --name a --stdin-json < patch.json  # patch.json has "name"
# after
ncl groups update --id g1 --stdin-json < patch.json           # patch.json has "name"

for (const k of Object.keys(stdin)) {
  if (Object.hasOwn(argv, k)) throw new Error(`duplicate key: ${k}`);
}

When it happens

Trigger: `ncl groups update --id g1 --name a --stdin-json` where stdin JSON also contains "name" (or "id").

Common situations: Partial migration to --stdin-json where some flags were left on the command line.

Related errors

• --stdin-json key "${key}" conflicts with argv key "${argvKey
• --stdin-json input exceeds ${MAX_STDIN_JSON_BYTES} bytes
• --stdin-json input is empty
• --stdin-json input is not valid JSON
• --stdin-json input must be one JSON object

AI-assisted analysis of nanocoai/nanoclaw@294ef2aee8 (2026-08-28). Data as JSON: /api/errors/ba2ac6f206bc635b. Report an issue: GitHub.