> For the complete documentation index, see [llms.txt](https://nexafin.gitbook.io/api/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://nexafin.gitbook.io/api/public-api/generate-a-token.md).

# Authentication

## API Keys

You can create and manage API keys in the **Settings > API Keys** panel at [app.nexafin.com](https://app.nexafin.com).

API keys use the prefix `nxfn_sk_` and expire 1 year after creation. When a key expires, create a new one from the settings panel. The full key is only shown once at creation — store it securely.

### Using your API key

Include the key in the `Authorization` header as a Bearer token:

```bash
curl -X GET https://app.nexafin.com/v1/transactions \
  -H "Authorization: Bearer nxfn_sk_your_api_key_here" \
  -H "Accept: application/json"
```

{% hint style="warning" %}
**Required headers for all API requests:**

* `Authorization: Bearer YOUR_API_KEY`
* `Accept: application/json`
* `Content-Type: application/json` (for POST/PUT requests with a JSON body)

Without the `Accept: application/json` header, error responses will return HTML instead of JSON.
{% endhint %}

{% hint style="info" %}
The Public API is a pro accounts feature. If you don't have a pro account, API requests will return a 401 Unauthorized response.
{% endhint %}

## Legacy tokens

If you previously created JWT tokens, they will continue to work until they expire. New integrations should use API keys instead.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## 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, and the optional `goal` query parameter:

```
GET https://nexafin.gitbook.io/api/public-api/generate-a-token.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

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.