> For the complete documentation index, see [llms.txt](https://docs.substreams.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.substreams.dev/how-to-guides/installing-the-cli/authentication.md).

# Substreams CLI Authentication

This guide explains how to authenticate when running a Substreams package (`.spkg`) with a provider, specifically using The Graph Market.

## Overview

`substreams auth` opens a browser so you can pick an organization (if you belong to more than one) and an API key. The CLI retrieves the selected key over the API — you do not copy and paste it — exchanges it for a JWT, and writes the token to `.substreams.env`.

## Prerequisites

* The [Substreams CLI](/how-to-guides/installing-the-cli.md) installed.
* A browser, so you can sign in and pick a key.
* An account with [The Graph Market](https://thegraph.market), or be ready to create one during login.

## Step 1: Run login

```bash
substreams auth
```

The command prints an approval URL (and tries to open it in your browser). Sign in, choose an organization if asked, then select an API key.

On success it writes `.substreams.env` with `SUBSTREAMS_API_TOKEN`. Add that file to `.gitignore`.

## Step 2: Load the credentials

```bash
. ./.substreams.env
```

Other `substreams` commands also read `.substreams.env` automatically when it is present next to the manifest (or in the current directory).

## Paste a JWT or API key instead

If you already have a Graph Market JWT or `server_` API key:

```bash
substreams auth --paste
```

Paste the value when prompted. An API key is exchanged for a JWT automatically.

You can also set the token yourself:

```bash
export SUBSTREAMS_API_TOKEN="<YOUR-JWT-TOKEN>"
```

## Step 3: Verify authentication

Run a test Substreams against Ethereum Mainnet:

```bash
substreams gui ethereum-common@v0.3.1 all_events --start-block=15000000
```

If the stream starts without an authentication error, your credentials are in place.

## Need Help?

If you encounter any issues or have questions, the StreamingFast team is available on [Discord](https://discord.gg/jZwqxJAvRs) to assist you.