> ## Documentation Index
> Fetch the complete documentation index at: https://neverminedag-sync-api-errors-9d14109.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Get a Nevermined API Key

> Let an AI agent obtain a Nevermined API key with a single sign-in from a human — captured automatically via a localhost callback, no copy-paste.

Every Nevermined call an agent makes needs an API key. The first key is the **one thing an agent can't mint itself** — a human must sign in once. But the agent can make that painless: it hosts a callback, hands the human one URL, and captures the key automatically when they sign in. After that, it stores and reuses the key forever.

## Useful for

* **Bootstrapping** a brand-new agent that has no credentials yet.
* Getting the key **back to the agent automatically** — no human copy-pasting secrets.
* Issuing **environment-specific** keys: a `sandbox:` key for testing, a `live:` key for production.

## Try it yourself

```text theme={null}
You are my autonomous payments agent. I don't have a Nevermined API key yet — get one for the sandbox environment with as little effort from me as possible.

Host a one-shot callback server on 127.0.0.1, then give me a single sign-in URL to open. Capture the key automatically from the redirect (don't make me copy-paste it), store it as NVM_API_KEY, and confirm it works by listing my payment methods. The key for this environment starts with "sandbox". Use the Nevermined `nevermined-payments` skill (https://github.com/nevermined-io/docs/tree/main/skills/nevermined-payments) for the steps and endpoints.
```

## How it works

There are two ways to get the key — the agent should prefer the embedded flow, which returns the key automatically.

<Steps>
  <Step title="Option A — embedded login (key returns automatically)">
    The agent hosts an HTTP server on `127.0.0.1:<port>` with a `/callback` route, then hands the human this URL:

    ```
    https://nevermined.app/auth/cli?callback_url=http://127.0.0.1:<port>/callback
    ```

    After the human signs in, the browser is redirected to `http://127.0.0.1:<port>/callback?nvm_api_key=<api-key>`. The agent reads `nvm_api_key` off that request and stores it.

    <Warning>
      The key arrives in the callback **query string** — the most-logged part of a request. The callback server must not log the request line, and the key belongs in a secret store, never on disk in the clear.
    </Warning>
  </Step>

  <Step title="Option B — manual paste (works anywhere)">
    If the agent can't host a localhost callback, the human creates the key in the app and pastes it back: sign in at [nevermined.app](https://nevermined.app) → **Settings → Global NVM API Keys** → create a key for the right environment. See [Get Your API Key](/docs/getting-started/get-your-api-key) for the full UI walkthrough.
  </Step>

  <Step title="Store, reuse, and use it">
    The key doesn't expire per request — store it once (e.g. `NVM_API_KEY`) and reuse it. Use it as a Bearer token on REST calls, or pass it to the SDK:

    <Tabs>
      <Tab title="REST">
        ```http theme={null}
        GET {API_BASE}/payment-methods
        Authorization: Bearer <api-key>
        ```
      </Tab>

      <Tab title="TypeScript">
        ```typescript theme={null}
        import { Payments } from '@nevermined-io/payments'

        const payments = Payments.getInstance({
          nvmApiKey: process.env.NVM_API_KEY, // "sandbox:..." or "live:..."
          environment: 'sandbox',
        })
        ```
      </Tab>

      <Tab title="Python">
        ```python theme={null}
        import os
        from payments_py import Payments, PaymentOptions

        payments = Payments.get_instance(
            PaymentOptions(nvm_api_key=os.environ["NVM_API_KEY"], environment="sandbox")
        )
        ```
      </Tab>
    </Tabs>

    <Note>
      Match the key to the environment: a `sandbox:` key only works against `api.sandbox.nevermined.app`, and `live:` only against `api.live.nevermined.app`.
    </Note>
  </Step>
</Steps>

## Related

<CardGroup cols={2}>
  <Card title="Get Your API Key" icon="key" href="/docs/getting-started/get-your-api-key">
    The web-app walkthrough for creating and managing keys.
  </Card>

  <Card title="Buy access" icon="cart-shopping" href="/docs/getting-started/ai-agent-purchase">
    With a key in hand, make your first autonomous purchase.
  </Card>
</CardGroup>