Introducing OAuth Support for AWS MCP Server

AWS MCP Server using the same credentials and sign-in methods that you already use for connecting to the AWS Management Console or AWS Command Line Interface (AWS CLI) through a familiar browser-based experience powered by industry-standard OAuth. This new sign-in path supports AWS Identity and Access Management (IAM) federation, AWS IAM Identity Center, and root or IAM users.

In addition, AWS is introducing several new security and governance tools, including: new global condition keys for OAuth, token introspection and revocation, dynamic client registration, new AWS CloudTrail elements, and a new API for headless OAuth connectivity. All of this is compatible with your existing IAM configuration including permissions, roles, and federated access.

In this post, you’ll learn how to connect your agents to the AWS MCP Server, understand how AWS Sign-In authorizes agent access, and manage access using new security and governance capabilities.

This walkthrough uses Claude Code, but the same steps apply to any agent that supports Model Context Protocol (MCP) such as Kiro, Codex, and Gemini. See Setting up the AWS MCP Server for how to connect the AWS MCP Server to an agent.

To connect an agent to the AWS MCP Server, you’ll need the IAM permissions required for OAuth-based sign-in. The following AWS CLI command adds a managed policy with required permissions to your IAM role (remember to replace with your IAM role):

Run the following command to add the AWS MCP Server endpoint to your agent’s configuration as shown in Figure 1:

claude mcp add --transport http aws-mcp https://aws-mcp.us-east-1.api.aws/mcp

The first time your agent needs to access the AWS MCP Server, it opens a browser and redirects you to an AWS Sign-In page, shown in Figure 2. Authenticate as you would on AWS console or AWS CLI, review the authorization request, and approve access. You should receive an Authorization successful message.

Figure 2: Review authorization request

Note that if you already have an active AWS Sign-In session (e.g., because you previously signed in to the console earlier in the day), you can reuse that session without needing to sign in again.

After connecting your agent to the AWS MCP Server, you can begin invoking tools provided by the server. To verify that Claude Code is connected to the AWS MCP Server, start Claude Code and run the following command:

/mcp

The command displays the configured MCP servers and confirms that the AWS MCP Server is connected and ready to use with your AWS credentials.

Figure 3 shows an example of a successful connection to the AWS MCP Server.

Figure 3: Verifying the AWS MCP Server connection in Claude Code

After the connection is established, you can ask Claude Code to invoke tools provided by the AWS MCP Server. For example, enter the following prompt:

Deploy a sample serverless web application into my development AWS account

Claude Code uses the AWS MCP Server to identify the active AWS account, confirm the target account, and describe the deployment it plans to perform before invoking AWS services on your behalf.

Figure 4 shows Claude Code confirming the active AWS account and outlining the resources that will be deployed.

Figure 4: Using Claude Code to deploy a sample serverless application through the AWS MCP Server

AWS Sign-In supports two authorization models for connecting agents to the AWS MCP Server:

• Interactive authorization for developer’s AI agents using browser based authentication
• Non-interactive (headless) authorization for applications and AI agents that already have AWS credentials and don’t have access to a browser

Note that authorizing an agent allows it to access the AWS MCP Server on your behalf. It doesn’t grant the agent additional AWS permissions. Every request is still evaluated using your existing IAM policies, SCPs, RCPs, permission boundaries, and other organizational controls.

In the interactive case, the agent first discovers the AWS Sign-In OAuth server and then registers itself as an OAuth client using Dynamic Client Registration (DCR). It then redirects you to an AWS Sign-In page where you authenticate and authorize access (step 2 in the preceding section). After successful authorization, AWS Sign-In then issues short-lived access tokens and refresh tokens that authorize the agent to access the AWS MCP Server on your behalf. AWS Sign-In automatically manages token issuance and token refresh, enabling authorized agents to continue accessing the AWS MCP Server without requiring you to repeatedly sign in.

The interactive authorization model supports three distinct sign-in methods: native AWS IAM credentials for individual developers, managed access through AWS IAM Identity Center for enterprises, and seamless federated access via third-party providers like Okta and Ping Identity for larger organizations

OAuth server metadata and DCR

Before an agent can request authorization, it must discover the AWS Sign-In OAuth endpoints and register itself as an OAuth client. AWS Sign-In supports OAuth metadata discovery and DCR, allowing supported agents to configure themselves automatically without requiring developers to manually provision OAuth client IDs and client secretsWhen an agent connects to the AWS MCP Server for the first time, it retrieves the AWS MCP Server’s protected resource metadata (RFC 9728) and the AWS Sign-In OAuth metadata (RFC 8414). The agent then uses RFC 7591)) to register with AWS Sign-In, obtain a client ID, and initiate the standard OAuth authorization code flow.

AWS Sign-In supports OAuth discovery and DCR for agents running on local workstations and supported hosted environments. For the current list of supported agents and environments, see Supported redirect URIs for the AWS MCP Server.

Non-interactive (headless) authorization is for agents and applications that run without a browser or human in the loop, and thus don’t require interactive sign-in. This allows agents that already have AWS credentials to obtain OAuth access tokens and connect to the AWS MCP Server. The following is an example of how to obtain an access token.

In the non-interactive case, AWS Sign-In implements the OAuth client credentials grant using AWS security credentials instead of a static client secret. Applications authenticate to the AWS Sign-In token endpoint using SigV4 creds, and AWS Sign-In returns a short-lived OAuth access token that can be used to access the AWS MCP Server.

Please note you may have to update the SDK and AWS CLI, please refer to CLI guide.

AWS Sign-In extends the existing IAM authorization model with capabilities for governing OAuth access to the AWS MCP Server. Administrators can use familiar IAM policies together with new OAuth-specific controls.

OAuth access is governed using IAM policies and requires the following IAM actions:

• signin:AuthorizeOAuth2Access – Allows users to sign in interactively using the OAuth authorization code flow
• signin:CreateOAuth2Token – Allows applications to obtain OAuth access tokens by exchanging authorization codes, refresh tokens, or using client credentials

When an application requests access, AWS Sign-In creates an OAuth authorization grant between the agent and the AWS MCP Server. This grant is represented as an IAM resource, which the preceding AWS Sign-In actions are authorized against.

arn:aws:signin:us-east-1:012345678910:service-principal/aws-mcp.amazonaws.com

OAuth authorization grants are represented as IAM resource enabling administrators to use standard IAM policy constructs, including global condition keys, together with OAuth-specific condition keys to control how authorization grants are created and used.

AWS Sign-In introduces OAuth-specific condition keys that allow administrators to govern how agents obtain OAuth authorization. The following examples demonstrate common governance patterns.

To restrict OAuth authorization to localhost:

In addition to accessing the AWS MCP Server with agents on your local workstation, AWS supports signing into the AWS MCP Server on select hosted providers through dynamic client registration. Click here to view the list of supported remote providers. Many organizations want to allow developers to authorize agents running on their local workstations while preventing OAuth tokens from being delivered to untrusted redirect URIs or using unsupported authorization flows. The following policy allows only the OAuth authorization code and refresh token flows for the AWS MCP server and restricts token delivery tolocalhost.

To deny access for a specific OAuth session

Use the aws:SignInSessionArn global condition key to deny authorization associated with a specific sign-in session. This allows administrators to contain a suspicious or compromised authorization session without affecting other active sessions.

These examples demonstrate common governance patterns. Additional IAM and SCP examples are available in the AWS Sign-In condition keys reference.

AWS Sign-In provides OAuth token introspection and token revocation APIs that allow administrators to build custom tools for token validation and revocation. Access to these APIs is controlled through the signin:IntrospectOAuth2Token and signin:RevokeOAuth2Token permissions. IAM principals with permissions are allowed to introspect and revoke tokens for the same account.

The introspection API can be used to determine whether a token is active and obtain information about the associated authorization. The revocation API allows administrators and security tools to revoke individual refresh tokens without affecting other active sessions. For example, if an organization needs to invalidate access for a specific OAuth authorization, account admins can revoke the associated refresh token without affecting other active sessions.

OAuth-related activities are recorded in AWS CloudTrail, including authorization requests, token issuance, token revocation, and token introspection events. CloudTrail logs also capture details such as the OAuth client, target the AWS MCP Server, redirect URI, authorization flow, and associated sign-in session. In addition, AWS API calls made using OAuth access tokens include the associated aws:SignInSessionArn context, allowing organizations to correlate API activity with the originating OAuth sign-in session.

This allows security teams to monitor OAuth usage, investigate authorization activity, detect anomalous behavior, and integrate OAuth events into existing auditing, compliance, and incident response workflows alongside other AWS activity.

Here’s a CloudTrail sample for an AuthorizeOAuth2Access event:

Here’s a CloudTrail sample for a CreateOAuth2Token event:

Additional audit events and logging details for calls made using OAuth access tokens to the AWS MCP Server can be found in Logging AWS MCP Server API calls using AWS CloudTrail.

AWS Sign-In support for OAuth enables you to securely connect to the AWS MCP Server using industry-standard authorization. This release simplifies application and agent integration with AWS while supporting your existing IAM setup, governance, and auditing capabilities.

To learn more, see Sign-In with OAuth 2.0 in the AWS Sign-In User Guide and Setting up the AWS MCP Server in the Agent Toolkit for AWS User Guide.