---
title: "OAuthTokenResolver"
id: oauthtokenresolver
slug: "/oauthtokenresolver"
description: "Resolves an OAuth access token at pipeline runtime and emits it for downstream components such as the SharePoint and Google Drive retrievers and fetchers."
---

# OAuthTokenResolver

Resolves an OAuth access token at pipeline runtime and emits it for downstream components such as the SharePoint and Google Drive retrievers and fetchers.

<div className="key-value-table">

|  |  |
| --- | --- |
| **Most common position in a pipeline** | At the start of a pipeline, feeding `access_token` into downstream components such as [`MSSharePointRetriever`](../retrievers/mssharepointretriever.mdx) or [`GoogleDriveRetriever`](../retrievers/googledriveretriever.mdx) |
| **Mandatory init variables** | `token_source`: The strategy that resolves the access token, for example `OAuthRefreshTokenSource` |
| **Mandatory run variables** | None for config-only sources. `subject_token`: a controller-injected per-request credential, mandatory only when the source requires it (for example `OAuthTokenExchangeSource`) |
| **Output variables** | `access_token`: A bearer token string |
| **API reference** | [OAuth](/reference/integrations-oauth) |
| **GitHub link** | https://github.com/deepset-ai/haystack-core-integrations/tree/main/integrations/oauth |
| **Package name** | `oauth-haystack` |

</div>

## Overview

`OAuthTokenResolver` resolves an OAuth access token when the pipeline runs and emits it on the `access_token` output socket. Downstream components – such as [`MSSharePointRetriever`](../retrievers/mssharepointretriever.mdx), [`MSSharePointFetcher`](../fetchers/mssharepointfetcher.mdx), [`GoogleDriveRetriever`](../retrievers/googledriveretriever.mdx), and [`GoogleDriveFetcher`](../fetchers/googledrivefetcher.mdx) – consume the token through a normal connection and never need to know how it was obtained.

The resolver itself is a thin wrapper. The actual work of getting a token is delegated to a pluggable **token source** that decides *where* the token comes from. This separation lets you swap authentication strategies (refresh-token grant, per-request token exchange, or a static long-lived token) without changing the rest of your pipeline.

### Token sources

You pass a token source to the resolver through the `token_source` parameter. All sources are importable from `haystack_integrations.utils.oauth`.

| Source | Use it when | Per-request input |
| --- | --- | --- |
| `OAuthRefreshTokenSource` | You have a single, fixed identity backed by a stored refresh token and want the source to exchange it for short-lived access tokens and cache them. | None |
| `OAuthTokenExchangeSource` | You serve multiple users (or run multiple replicas) and want to exchange an incoming per-request user assertion for a downstream token, with no persistent storage. Implements RFC 8693 token exchange and Microsoft's on-behalf-of flow. | `subject_token` |
| `OAuthStaticTokenSource` | Your provider issues a non-expiring token that you manage out of band (for example Slack or Notion). | None |

When the configured source needs a per-request credential (`OAuthTokenExchangeSource` sets `requires_subject_token = True`), the resolver declares a **mandatory** `subject_token` run input. This is a controller-injected credential – for example an incoming user assertion – not a value chosen by an end user. For config-only sources (`OAuthRefreshTokenSource`, `OAuthStaticTokenSource`), the resolver declares no run input and acts as a source node.

:::info[Scopes are provider-specific]

The OAuth scopes you request depend on the downstream service. For Microsoft Graph, that means scopes such as `https://graph.microsoft.com/Files.Read.All`; for Google Drive, scopes such as `https://www.googleapis.com/auth/drive.readonly`. Always consult your identity provider's documentation for the exact scope values.

:::

### Installation

Install the OAuth integration with:

```shell
pip install oauth-haystack
```

## Usage

### On its own

Resolve a token with a stored refresh token using `OAuthRefreshTokenSource`. The refresh token is read from an environment variable through the [Secret API](../../concepts/secret-management.mdx):

```python
from haystack.utils import Secret
from haystack_integrations.components.connectors.oauth import OAuthTokenResolver
from haystack_integrations.utils.oauth import OAuthRefreshTokenSource

resolver = OAuthTokenResolver(
    token_source=OAuthRefreshTokenSource(
        token_url="https://login.microsoftonline.com/common/oauth2/v2.0/token",
        client_id="aaa-bbb-ccc",
        refresh_token=Secret.from_env_var("MS_REFRESH_TOKEN"),
        scopes=[
            "https://graph.microsoft.com/Files.Read.All",
            "offline_access",
        ],
    ),
)

access_token = resolver.run()["access_token"]
```

For a provider that issues long-lived, non-expiring tokens, use `OAuthStaticTokenSource` instead:

```python
from haystack.utils import Secret
from haystack_integrations.components.connectors.oauth import OAuthTokenResolver
from haystack_integrations.utils.oauth import OAuthStaticTokenSource

resolver = OAuthTokenResolver(
    token_source=OAuthStaticTokenSource(token=Secret.from_env_var("SERVICE_TOKEN")),
)

access_token = resolver.run()["access_token"]
```

For multi-user backends, use `OAuthTokenExchangeSource`. The resolver then requires a per-request `subject_token`:

```python
from haystack_integrations.components.connectors.oauth import OAuthTokenResolver
from haystack_integrations.utils.oauth import OAuthTokenExchangeSource

resolver = OAuthTokenResolver(
    token_source=OAuthTokenExchangeSource(
        token_url="https://login.microsoftonline.com/<tenant>/oauth2/v2.0/token",
        client_id="aaa-bbb-ccc",
        subject_token_param="assertion",
        grant_type="urn:ietf:params:oauth:grant-type:jwt-bearer",
        scopes=["https://graph.microsoft.com/Files.Read.All"],
        extra_token_params={"requested_token_use": "on_behalf_of"},
    ),
)

# `subject_token` is the incoming per-request user assertion, injected by your application.
access_token = resolver.run(subject_token="<incoming-user-assertion>")["access_token"]
```

### In a pipeline

In a pipeline, connect the resolver's `access_token` output to the `access_token` input of one or more downstream components. The example below wires the resolver into a [`MSSharePointRetriever`](../retrievers/mssharepointretriever.mdx) so that searching SharePoint requires only a query at runtime:

```python
from haystack import Pipeline
from haystack.utils import Secret
from haystack_integrations.components.connectors.oauth import OAuthTokenResolver
from haystack_integrations.utils.oauth import OAuthRefreshTokenSource
from haystack_integrations.components.retrievers.microsoft_sharepoint import (
    MSSharePointRetriever,
)

pipeline = Pipeline()
pipeline.add_component(
    "resolver",
    OAuthTokenResolver(
        token_source=OAuthRefreshTokenSource(
            token_url="https://login.microsoftonline.com/common/oauth2/v2.0/token",
            client_id="aaa-bbb-ccc",
            refresh_token=Secret.from_env_var("MS_REFRESH_TOKEN"),
            scopes=[
                "https://graph.microsoft.com/Files.Read.All",
                "https://graph.microsoft.com/Sites.Read.All",
                "offline_access",
            ],
        ),
    ),
)
pipeline.add_component("retriever", MSSharePointRetriever(top_k=5))
pipeline.connect("resolver.access_token", "retriever.access_token")

result = pipeline.run({"retriever": {"query": "quarterly roadmap"}})
documents = result["retriever"]["documents"]
```

A single `access_token` output can be connected to several downstream inputs. For a full retrieve-then-fetch pipeline that feeds the same token to both a retriever and a fetcher, see the [`MSSharePointFetcher`](../fetchers/mssharepointfetcher.mdx) and [`GoogleDriveFetcher`](../fetchers/googledrivefetcher.mdx) pages.