tinyhumansai/openhuman · error · ValidationError

Invalid ${paramName}: '${value}'. Must be a positive integer

Error message

Invalid ${paramName}: '${value}'. Must be a positive integer.

What it means

The string branch of validatePositiveInt(): the value is a string, so it is parsed with Number.parseInt(value, 10); when parsing yields NaN or the result is <= 0 it throws ValidationError "Invalid <param>: '<value>'. Must be a positive integer." Note parseInt('12abc') succeeds as 12 — only fully unparseable or non-positive strings fail.

Source

Thrown at app/src/lib/mcp/validation.ts:86

    }
  });
}

/**
 * Validate a positive integer parameter (e.g. message IDs)
 */
export function validatePositiveInt(value: unknown, paramName: string): number {
  if (typeof value === 'number') {
    if (!Number.isInteger(value) || value <= 0) {
      throw new ValidationError(`Invalid ${paramName}: ${value}. Must be a positive integer.`);
    }
    return value;
  }

  if (typeof value === 'string') {
    const intValue = Number.parseInt(value, 10);
    if (Number.isNaN(intValue) || intValue <= 0) {
      throw new ValidationError(`Invalid ${paramName}: '${value}'. Must be a positive integer.`);
    }
    return intValue;
  }

  throw new ValidationError(`Invalid ${paramName}: ${String(value)}. Must be a positive integer.`);
}

/**
 * Validate optional ID (can be undefined)
 */
export function validateOptionalId(value: unknown, paramName: string): number | string | undefined {
  if (value === undefined || value === null) {
    return undefined;
  }
  return validateId(value, paramName);
}

View on GitHub (pinned to 7491200858)

Solutions

1. Send the exact numeric string without decoration; strip separators/whitespace and validate with /^\d+$/ and > 0 before calling.
2. Coerce at the boundary: const n = Number(value); if (Number.isInteger(n) && n > 0) use n.
3. Reject empty inputs in the form layer so '' never reaches the validator.
4. For IDs that legitimately contain letters, this validator is wrong — use validateId() (int-or-username) instead.

Example fix

// before
await tool({ message_id: el.dataset.id }); // may be '' or 'msg-7'

// after
const raw = el.dataset.id ?? '';
if (!/^\d+$/.test(raw) || Number(raw) < 1) throw new UserInputError('Pick a valid message');
await tool({ message_id: Number(raw) });

const m = /^\d+$/.exec(raw ?? '');
const id = m && Number(m[0]) > 0 ? Number(m[0]) : undefined;
if (id === undefined) throw new UserInputError('Expected a positive integer string');
await tool({ message_id: id });

function isPositiveIntString(v: unknown): v is string {
  return typeof v === 'string' && /^\d+$/.test(v) && Number(v) > 0;
}

try {
  validatePositiveInt(value, 'cursor');
} catch (err) {
  if (err instanceof ValidationError) {
    return badRequest(err.message); // surface to tool caller as 400
  }
  throw err;
}

When it happens

Trigger: Passing a string param that is empty, non-numeric ('abc', 'id-42'), a float string parsing to <= 0 ('0', '-3'), or numeric-prefixed junk ('x9'). Common when IDs come from URL/query params, DOM datasets, or user input without validation.

Common situations: Tool invoked from a web UI where IDs are strings from the DOM; empty-string defaults leaking from forms; locale-formatted numbers ('1,000') failing parseInt; trailing whitespace usually tolerable but embedded letters fail.

Related errors

• Invalid ${paramName}: ${value}. Must be a positive integer.
• Invalid ${paramName}: ${String(value)}. Must be a positive i
• "{key}" is required
• mascot manifest: missing mascots array
• mascot manifest: no renderable mascots

AI-assisted analysis of tinyhumansai/openhuman@7491200858 (2026-08-17). Data as JSON: /api/errors/d4deeccf191ebd6f. Report an issue: GitHub.