# Tools

Use the tools listed on this page to explore and test our APIs.

## Postman collection

To get started, you will need a [Postman account](https://www.postman.com/), a [Rev AI account](https://www.rev.ai/auth/signup) and a [Rev AI access token](/get-started#step-1-get-your-access-token).

Easily explore and interact with our APIs without writing any code with [Postman](https://www.postman.com/) and the [Rev AI Postman collection](https://www.postman.com/revai-dev/workspace/rev-ai-developers/overview).

Postman is a free-to-use development tool for working with APIs. A Postman collection is a way to group API requests templates together into a bundle that can be shared or copied for others to use.

[Learn more about the Rev AI Postman collection](https://www.postman.com/revai-dev/workspace/rev-ai-developers/overview).

## fstalign

`fstalign` is a tool for creating alignment between two sequences of tokens (referred to as "reference" and "hypothesis"). It has two key functions: computing word error rate (WER) and aligning NLP-formatted references with CTM hypotheses.

Due to its use of OpenFST and lazy algorithms for text-based alignment, fstalign is efficient for calculating WER while also providing significant flexibility for different measurement features and error analysis.

[Learn more about fstalign](https://github.com/revdotcom/fstalign).