nexu-io/open-design · error

project_files.read_json only supports .json files

Error message

project_files.read_json only supports .json files

What it means

executeProjectFilesReadJson (refresh.ts:587-588) requires the resolved file path to end with '.json'. This bounds the tool to JSON parsing only (it immediately JSON.parse's the contents), so non-JSON files are rejected before any filesystem traversal.

Source

Thrown at apps/daemon/src/live-artifacts/refresh.ts:588

    if (!matched) continue;
    const result: BoundedJsonObject = {
      path: file.path,
      name: file.name,
      size: file.size,
      mtime: file.mtime,
      kind: file.kind ?? 'file',
      mime: file.mime ?? 'application/octet-stream',
    };
    if (preview !== undefined) result.preview = preview;
    matches.push(result);
  }

  return asBoundedRefreshOutput({ toolName: 'project_files.search', query: query ?? '', count: matches.length, truncated: allFiles.length > matches.length && matches.length >= maxResults, matches });
}

async function executeProjectFilesReadJson(options: ExecuteLocalDaemonRefreshSourceOptions): Promise<BoundedJsonObject> {
  const filePath = selectJsonPath(options.source.input as ProjectFilesReadJsonInput);
  if (!filePath.endsWith('.json')) throw new Error('project_files.read_json only supports .json files');
  const dir = projectDir(options.projectsRoot, options.projectId);
  const target = path.resolve(dir, filePath);
  const [dirReal, targetLinkStat] = await Promise.all([realpath(dir), lstat(target)]);
  if (targetLinkStat.isSymbolicLink()) throw new Error('project_files.read_json does not follow symlinks');
  const targetReal = await realpath(target);
  if (!targetReal.startsWith(`${dirReal}${path.sep}`) && targetReal !== dirReal) {
    throw new Error('project_files.read_json path escapes project dir');
  }
  const entryStat = await stat(targetReal);
  if (!entryStat.isFile()) throw new Error('project_files.read_json path must be a file');
  if (entryStat.size > 256 * 1024) throw new Error('project_files.read_json file exceeds 256KB');
  if (options.signal?.aborted === true) throw options.signal.reason;
  let parsed: BoundedJsonValue;
  try {
    parsed = JSON.parse(await readFile(targetReal, 'utf8')) as BoundedJsonValue;
  } catch {
    throw new Error(`project_files.read_json could not parse JSON at ${filePath}`);
  }

View on GitHub (pinned to 5be4028344)

Solutions

1. Use a '.json' file path (lowercase).
2. If your data is JSONC/JSON5/YAML, convert it to plain JSON first, or use a different source type.
3. Rename or copy the file with a .json extension if its contents are valid JSON.

Example fix

// before
const input = { path: 'config.yaml' };
// throws `project_files.read_json only supports .json files`

// after
const input = { path: 'config.json' };

function assertJsonFilePath(p: string): void {
  if (!p.toLowerCase().endsWith('.json')) {
    throw new Error('project_files.read_json only supports .json files');
  }
}

function isJsonFilePath(p: unknown): p is string {
  return typeof p === 'string' && p.toLowerCase().endsWith('.json');
}

When it happens

Trigger: input.path (or file/name) resolves to a path whose final extension is not '.json', e.g. 'data.txt', 'config.yaml', 'package.jsonc'.

Common situations: Pointing the read_json tool at a JSONC/YAML/TXT file by mistake; a path with no extension; a case-sensitivity issue such as '.JSON' (the check is case-sensitive on lowercased extension only via endsWith).

Related errors

• project_files.read_json requires input.path
• project_files.read_json does not follow symlinks
• project_files.read_json path escapes project dir
• project_files.read_json path must be a file
• project_files.read_json file exceeds 256KB

AI-assisted analysis of nexu-io/open-design@5be4028344 (2026-08-12). Data as JSON: /api/errors/5f1afd3e69bb2ec3. Report an issue: GitHub.