How Neon credentials map to S3 access keys

Neon Object Storage uses the same scoped-credential system as [AI Gateway](/guides/ai-gateway-authentication): one credential API mints branch-scoped tokens that differ by scope (Object Storage uses `storage:read` and `storage:write`). You create a scoped credential via the Neon API, and it maps directly to the S3 Access Key ID and Secret Access Key your SDK expects. No AWS account or IAM configuration required.

## Creating a credential

An object storage credential requires at minimum one of:

- [`storage:read`](/guides/object-storage-authentication#read-vs-write-scopes): allows GetObject, HeadObject, ListObjects, and ListBuckets
- [`storage:write`](/guides/object-storage-authentication#read-vs-write-scopes): allows all read operations plus PutObject and DeleteObject

**CLI**

Create a credential with the [Neon CLI](/guides/apis-sdks-cli-credentials):

```bash
neon credentials create --scope storage:read --scope storage:write --name my-app-credential
```

The `api_token` and `s3_secret_access_key` are printed once, so store them right away. Map `token_id` to `AWS_ACCESS_KEY_ID` and `s3_secret_access_key` to `AWS_SECRET_ACCESS_KEY` (see [Mapping to your S3 SDK](/guides/object-storage-authentication#mapping-to-your-s3-sdk)). Run it in a directory [linked](/guides/apis-sdks-cli-link) to your project, or pass `--project-id` and `--branch`.

**Console**

In the Neon Console, click **Connect** at the top of the sidebar and open the **Storage** tab. Use the client selector to pick **S3 client**, **Files SDK**, or **Python** for a ready-to-run snippet, or **Parameters only** for the raw `.env`. Click **Reveal credential** to show `AWS_SECRET_ACCESS_KEY`, **Copy credentials** to copy it, or **Rotate credentials** to issue new keys.

```text
AWS_ENDPOINT_URL_S3=https://br-cool-darkness-a1b2c3d4.storage.c-1.us-east-2.aws.neon.tech
AWS_ACCESS_KEY_ID=nak_live_...
AWS_SECRET_ACCESS_KEY=nsk_live_...
AWS_REGION=us-east-2
```

The Connect dialog reveals and rotates the current credential. To list all credentials for the branch or revoke one, use the [Neon CLI](/guides/apis-sdks-cli-credentials) or the API (below).

**API**

```bash
curl -X POST "https://console.neon.tech/api/v2/projects/{project_id}/branches/{branch_id}/credentials" \
  -H "Authorization: Bearer $NEON_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"scopes": ["storage:read", "storage:write"], "principal_type": "user", "name": "my-app-credential"}'
```

The `name` and `expires_at` fields are optional.

**Warning:** `expires_at` is not currently enforced. A credential created with an `expires_at` value in the past still authenticates successfully. Don't rely on it for access control; revoke credentials explicitly instead. See [Revoking credentials](/guides/object-storage-authentication#revoking-credentials).

The response includes these fields. Both secrets are returned once only, so store them immediately:

```json
{
  "token_id": "nak_live_...",
  "token_id_short": "9043e374b584...",
  "name": "my-app-credential",
  "api_token": "nt_live_...",
  "s3_secret_access_key": "nsk_live_...",
  "scopes": ["storage:read", "storage:write"],
  "branch_id": "br-winter-pond-aptw82ef",
  "created_at": "2026-06-08T00:00:00Z",
  "expires_at": null
}
```

## Mapping to your S3 SDK

| Neon credential field  | S3 SDK parameter  |
| ---------------------- | ----------------- |
| `token_id`             | Access Key ID     |
| `s3_secret_access_key` | Secret Access Key |
| `us-east-2`            | Region            |

**Warning:** Both `api_token` and `s3_secret_access_key` are returned exactly once at creation. They cannot be retrieved again. Store them in a secrets manager or environment variables before the response is lost.

Configure your S3 client using these values:

**TypeScript**

```typescript
import { S3Client } from '@aws-sdk/client-s3';

const client = new S3Client({
  region: process.env.AWS_REGION,
  endpoint: process.env.AWS_ENDPOINT_URL_S3,
  credentials: {
    accessKeyId: process.env.AWS_ACCESS_KEY_ID!,   // token_id
    secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY!, // s3_secret_access_key
  },
  forcePathStyle: true,
});
```

**Python**

```python
import boto3, os

client = boto3.client(
    's3',
    region_name=os.environ['AWS_REGION'],
    endpoint_url=os.environ['AWS_ENDPOINT_URL_S3'],
    aws_access_key_id=os.environ['AWS_ACCESS_KEY_ID'],         # token_id
    aws_secret_access_key=os.environ['AWS_SECRET_ACCESS_KEY'], # s3_secret_access_key
)
```

**AWS CLI**

```bash
# These env vars are already in AWS-standard form; no remapping needed.
export AWS_ACCESS_KEY_ID=nak_live_...
export AWS_SECRET_ACCESS_KEY=nsk_live_...
export AWS_REGION=us-east-2
```

**Note:** `forcePathStyle: true` is required for the AWS SDK for JavaScript when using a custom S3 endpoint.

## Pull credentials with neon

For local development, `neon env pull` writes storage credentials to your `.env` file automatically. No manual copy-paste from the API response:

```bash
neon env pull --file .env.local
```

This populates `AWS_ENDPOINT_URL_S3`, `AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`, and `AWS_REGION` for the current branch alongside your database connection string. To check the current credential status:

```bash
neon config status
```

For production deployments, use the [API-based workflow](/guides/object-storage-authentication#creating-a-credential) to create named, scoped credentials.

## Read vs write scopes

Issue separate credentials for read and write access when you want to limit exposure:

- **Server-side code** that uploads files: `storage:write` (includes read)
- **Client-side or CDN code** that only fetches: `storage:read`
- **Presigned URLs**: generate these server-side from a `storage:write` credential. The URL itself requires no credential in the browser.

The S3 data plane enforces scope on every request. A credential without a storage scope returns `403 AccessDenied` on all S3 operations. Server-side COPY requires both `storage:read` and `storage:write`.

## Credentials in Neon Functions

When your code runs inside Neon Functions, Neon injects storage credentials automatically. You don't need to create a credential:

| Variable                | Value                                    |
| ----------------------- | ---------------------------------------- |
| `AWS_ACCESS_KEY_ID`     | S3 Access Key ID                         |
| `AWS_SECRET_ACCESS_KEY` | S3 Secret Access Key                     |
| `AWS_ENDPOINT_URL_S3`   | Branch S3 endpoint URL                   |
| `AWS_REGION`            | Object storage region (e.g. `us-east-2`) |

See [Environment variables](/guides/neon-functions-environment-variables) for the full list of variables Neon injects into a function.

Credentials are branch-scoped and tied to the function's serving branch. Injected values are defaults, not reserved names: a user-supplied environment variable with the same name (set via `--env` or in `neon.ts`) overrides the injected credential, same as any other Neon-injected variable. See [Environment variables](/guides/neon-functions-environment-variables#user-defined-variables). Because the credentials use AWS-standard names, the AWS SDK picks them up automatically when you don't override them. Only `forcePathStyle` needs explicit configuration:

```typescript
import { S3Client } from '@aws-sdk/client-s3';

const client = new S3Client({
  region: process.env.AWS_REGION,
  endpoint: process.env.AWS_ENDPOINT_URL_S3,
  credentials: {
    accessKeyId: process.env.AWS_ACCESS_KEY_ID!,
    secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY!,
  },
  forcePathStyle: true,
});
```

## How branch binding works

Each credential is tied to the branch it was created on. It is valid for:

- That branch (the anchor branch)
- Any branch descended from it: preview branches, feature branches, CI branches

It's **not** valid for branches outside that lineage.

```
main  ──── credential valid here
  └── preview/feature-x  ──── and here
        └── preview/sub-branch  ──── and here
staging  ──── credential NOT valid here (different lineage)
```

## Listing credentials

To list all credentials for the current branch (name, key ID, creation date, and last used time), use the [Neon CLI](/guides/apis-sdks-cli-credentials) (`neon credentials list`) or the API:

```bash
curl "https://console.neon.tech/api/v2/projects/{project_id}/branches/{branch_id}/credentials" \
  -H "Authorization: Bearer $NEON_API_KEY"
```

This returns credential metadata. Secrets are never returned after creation.

## Revoking credentials

To revoke, use the [Neon CLI](/guides/apis-sdks-cli-credentials) (`neon credentials revoke <token_id>`) or the API:

```bash
curl -X DELETE "https://console.neon.tech/api/v2/projects/{project_id}/branches/{branch_id}/credentials/{token_id}" \
  -H "Authorization: Bearer $NEON_API_KEY"
```

With the [Neon CLI](/guides/apis-sdks-cli-credentials), run `neon credentials list` to find a credential, then revoke it by its `token_id`:

```bash
neon credentials revoke <token_id>
```

To rotate a credential in place, run `neon credentials rotate <token_id>`. This mints a new `s3_secret_access_key` while keeping the `token_id` (your `AWS_ACCESS_KEY_ID`) the same, so you only update the secret. Otherwise, create a new credential, update your environment variables, then revoke the old one.

## Common errors

| Error                       | Cause                               | Fix                                                                                                                           |
| --------------------------- | ----------------------------------- | ----------------------------------------------------------------------------------------------------------------------------- |
| `403 InvalidAccessKeyId`    | `token_id` is wrong or revoked      | Check `AWS_ACCESS_KEY_ID` is set correctly. If you rotated the credential, update the value.                                  |
| `403 SignatureDoesNotMatch` | Wrong secret access key             | Check `AWS_SECRET_ACCESS_KEY` is the value from credential creation. Secrets can't be retrieved. Revoke and recreate if lost. |
| `403 AccessDenied`          | Credential lacks the required scope | Recreate with `storage:write` for uploads/deletes                                                                             |
| `403 AccessDenied`          | Branch not in credential lineage    | Use a credential created on this branch or an ancestor                                                                        |

## Related pages

- [Buckets](./object-storage-buckets.md)
- [Objects](./object-storage-objects.md)
- [Object storage logs](./object-storage-logs.md)

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