Failed to parse service CLI output as JSON

Error message

Failed to parse service CLI output as JSON: ${err instanceof Error ? err.message : String(err)}

What it means

parseServiceCliOutput expects the raw stdout of an openhuman-core CLI invocation to be one JSON document. This variant throws when `JSON.parse(raw)` itself fails, meaning the output was not valid JSON at all — the CLI printed human-readable text, a banner, or nothing, where the caller contract demands a machine-readable CommandResponse envelope.

Solutions

Log/inspect the raw string passed in — what the CLI actually printed tells you which of the causes applies
Rebuild/reinstall openhuman-core to the version matching the app (`cargo build --bin openhuman-core`, or let the desktop shell manage it) so stdout is a single JSON document
Ensure the CLI is invoked in its machine-output mode and that log lines go to stderr, not stdout
If stdout legitimately contains noise, extract the last parseable JSON line before handing it to parseServiceCliOutput

Example fix

// before
const resp = parseServiceCliOutput(raw);

// after (tolerate leading non-JSON log noise on stdout)
const jsonStart = raw.indexOf('{');
const resp = parseServiceCliOutput(jsonStart > 0 ? raw.slice(jsonStart) : raw);

Defensive patterns

Strategy: try-catch

Validate before calling

const looksLikeJson = (raw: string): boolean =>
  raw.trimStart().startsWith('{') || raw.trimStart().startsWith('[');

if (!looksLikeJson(raw)) {
  // Surface the raw output for diagnosis instead of parsing
  throw new Error(`Core CLI produced non-JSON output: ${raw.slice(0, 200)}`);
}

Try / catch

try {
  const resp = parseServiceCliOutput<MyResult>(raw);
} catch (err) {
  if (err instanceof Error && err.message.includes('parse service CLI output as JSON')) {
    logRawCliOutput(raw); // the raw string is the only useful diagnostic
    throw new CoreCliOutputError(raw);
  }
  throw err;
}

Prevention

Always capture the raw CLI stdout alongside the parse error — the message alone says nothing about what was printed
Keep CLI versions pinned to the UI build so stdout stays a single JSON document
Route CLI diagnostics to stderr and reserve stdout for the JSON envelope

When it happens

Trigger: Invoking a core CLI subcommand through this parser when the binary writes non-JSON to stdout: a human-readable help/banner line, an error message printed to stdout instead of stderr, output truncated because the process was killed mid-write, a version skew where the CLI no longer emits pure JSON, or an empty string.

Common situations: openhuman-core binary version mismatched against the UI after a partial rebuild or update; the core process crashed and the shell captured its partial/empty stdout; a new CLI subcommand added logging to stdout; tests feeding canned string output into the parser.

Understand the failure class

Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

AI-assisted analysis of tinyhumansai/openhuman@7491200858 (2026-08-17). Data as JSON: /api/errors/8bcf8c4ba82460ce. Report an issue: GitHub.

Appendix: source

Thrown at app/src/utils/tauriCommands/common.ts:92

  if (!value || typeof value !== 'object' || Array.isArray(value)) {
    return false;
  }
  const candidate = value as { result?: unknown; logs?: unknown };
  if (!('result' in candidate) || !('logs' in candidate)) {
    return false;
  }
  if (!Array.isArray(candidate.logs)) {
    return false;
  }
  return candidate.logs.every(entry => typeof entry === 'string');
}

export function parseServiceCliOutput<T>(raw: string): CommandResponse<T> {
  let parsed: unknown;
  try {
    parsed = JSON.parse(raw);
  } catch (err) {
    throw new Error(
      `Failed to parse service CLI output as JSON: ${err instanceof Error ? err.message : String(err)}`
    );
  }
  if (!isCommandResponse<T>(parsed)) {
    throw new Error(
      'Failed to parse service CLI output as JSON: parsed value does not match CommandResponse shape'
    );
  }
  return parsed;
}

/**
 * Typed marker for the CEF "IPC bridge not wired" failure mode. The vendored
 * `app/src-tauri/vendor/tauri-cef/crates/tauri/scripts/ipc-protocol.js` falls
 * back to `window.ipc.postMessage(...)` whenever the custom-protocol fetch
 * rejects (network blip, navigation interrupt, mid-session re-entry). On CEF
 * `window.ipc` is never wired — `app/src-tauri/src/cef_impl.rs` drops the
 * `ipc_handler` registration — so the fallback throws

View on GitHub (pinned to 7491200858)