# API Directories

[Programmableweb.com](https://www.programmableweb.com/apis/directory) is a go-to source for API-related information.

To learn about APIs, you can use their API University. To gather information about your target, use the API Directory, a searchable database of over 23,000 APIs. Expect to find API endpoints, version information, business logic information, the status of the API, source code, SDKs, articles, API documentation, and a changelog.

<figure><img src="/files/NPWMPDBqTfvtXRvZgOn9" alt=""><figcaption><p>Twilio API page on programmableweb.com</p></figcaption></figure>

Click through the various tabs in the directory listing and note the information you find. To see the API endpoint location, portal location, and authentication model. To see information about the APIs version history, select a specific version listed under the Versions tab. In this case, both the portal and endpoint links lead to API documentation as well. In the case of Twilio, you can see all the specs related to the current version of the REST API.

<figure><img src="/files/otte9ETSjmEUXgsJzmym" alt=""><figcaption><p>The Twilio specs page on programmableweb.com</p></figcaption></figure>

On the Twilio specs page, you can learn all sorts of useful information about the API. For instance, the API endpoint URL is listed, the forum for the API, the developer support URL, the authentication model, and more are all listed on this page. At the bottom of the Specs page, you can also see articles related to the API and developers of the API, all of which could prove useful when attacking the API.


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://davidjosearaujo.gitbook.io/online-courses/api-penetration-testing-course/api-reconnaissance/passive-reconnaissance/api-directories.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.