Do not combine numeric and math
2026-03-03 · Numeric captchas
A digit code is not a sum. A sum is not a digit code. Send one or the other.
math: true switches engine. The arithmetic model expects an expression such as 14 + 9, not a code such as 482915. A code sent to the math engine is the wrong problem.
numeric: true on a sum is also wrong. The plus sign is not a digit, and the fold rules are for letters that look like digits.
Look at the image for one second before you set flags. If you see an operator, it is math. If you see only a code, it is numeric or plain text.
Mixed batches should set the option on each item, not only at the top.
Ready to call it? Start with the quickstart, the API guide, or pricing.