SpecTest — unit tests from copied code, API tests from contracts

Writes tests for code you copy or upload, on your computer with Chrome's built-in AI, and API tests from OpenAPI contracts.

SpecTest writes tests for you from code you copy, from a source file, or from an API contract. Copy a function or a class from anywhere: your editor, a code review, a web page. Click the SpecTest button. It shows what you copied and which language it is in, and one click writes unit tests for it in the test framework that language normally uses. You can change the language, the framework, or add an instruction before it writes. The unit tests are written by the AI model built into Chrome, on your own computer. There is no key to enter, no account, and your code is not sent anywhere. Chrome downloads the model once the first time; after that it works offline. The tests are a model's first draft: read them and run them before you keep them. Give SpecTest an OpenAPI or Swagger contract instead, and it builds contract tests for a running API without any AI: for every operation, the documented success response and its required fields, missing and wrongly typed fields, values outside the allowed range, requests without credentials, and records that do not exist. You pick the operations and the checks, choose the language, and download one test file. You can also upload a source file or a contract file, or open a contract on a web page and click the button there. Limits Chrome's built-in model needs Chrome 138 or newer on a computer with enough memory and disk; on other computers SpecTest says why and lets you use your own AI provider key instead. Contract tests call a real running service, so point them at a test environment.