AdminIdentity providers

Use WIF with AWS

Authenticate AWS workloads on Lambda, EC2, ECS, or EKS to the Claude API with Workload Identity Federation and STS-issued identity tokens.

AWS workloads can authenticate to the Claude API without static API keys by exchanging an AWS-signed OIDC identity token. The recommended path calls the AWS STS GetWebIdentityToken API, which works anywhere the workload has AWS credentials: Lambda, EC2, ECS, and EKS. EKS workloads can alternatively use the Kubernetes projected-token path, which has fewer configuration steps but only works inside a pod.

This guide shows both paths. For the underlying concepts (service accounts, federation issuers, and federation rules), see Workload Identity Federation.

Prerequisites

Familiarity with Workload Identity Federation (WIF) concepts: service accounts, federation issuers, and federation rules.
An AWS workload (EKS pod, ECS task, Lambda function, or EC2 instance) with an attached IAM role.
The aws CLI or an AWS SDK available in the workload.
Permission to create service accounts, federation issuers, and federation rules in the Claude Console for your Anthropic organization.

Use STS web identity tokens (recommended)

The AWS STS GetWebIdentityToken API returns an OIDC token signed by AWS that asserts the caller’s IAM identity. Because it uses the workload’s ambient AWS credentials, the same integration covers Lambda, EC2, ECS, and EKS.

Configure AWS

1
Enable outbound web identity federation for the account
This is an account-level flag, off by default. In the AWS console, open IAM, select Account settings, and enable Outbound web identity federation. To enable it programmatically:
python3 -c "import boto3; boto3.client('iam').enable_outbound_web_identity_federation()"
If this is not enabled, calls to GetWebIdentityToken fail with OutboundWebIdentityFederationDisabledException.

Grant the workload’s IAM role permission to call the API

Attach this policy to the IAM role that your Lambda function, EC2 instance, or ECS task runs as:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": ["sts:GetWebIdentityToken"],
      "Resource": "*"
    }
  ]
}

3
Find your account’s STS issuer URL
After you enable outbound federation, the IAM > Account settings page shows a Get Token Issuer URL field with a value of the form https://<uuid>.tokens.sts.global.api.aws. This URL is unique to your AWS account. Copy it for the next step. To retrieve it programmatically:
python3 -c "import boto3; print(boto3.client('iam').get_outbound_web_identity_federation_info())"

Configure Anthropic

In the Claude Console, go to the Workload identity page (platform.claude.com/settings/workload-identity-federation), click Connect workload, and select the AWS tile. The wizard walks you through registering the issuer, creating a service account, and creating a federation rule.

The wizard creates these resources for you. Use the following values whether you enter them in the wizard or send them to the Admin API:

Federation issuer: Register your account’s STS issuer URL, which you copied in the previous step. It exposes a public JWKS endpoint, so use discovery mode.

{
  "name": "aws-sts",
  "issuer_url": "https://<uuid>.tokens.sts.global.api.aws",
  "jwks": { "type": "discovery" }
}

Federation rule: Match the audience you pass to GetWebIdentityToken and the calling role’s ARN in the sub claim, in the form arn:aws:iam::<account>:role/<role-name>. The token also carries an https://sts.amazonaws.com/ claim with aws_account, org_id, principal_id, and any request_tags you passed. For finer control, match on those with a Common Expression Language (CEL) condition.

{
  "name": "prod-inference",
  "issuer_id": "fdis_...",
  "match": {
    "subject_prefix": "arn:aws:iam::123456789012:role/inference-worker",
    "audience": "https://api.anthropic.com"
  },
  "target": { "type": "service_account", "service_account_id": "svac_..." },
  "workspace_id": "wrkspc_...",
  "oauth_scope": "workspace:developer",
  "token_lifetime_seconds": 600
}

Be as specific as the workload allows. Match the exact role ARN. Broaden subject_prefix (for example, to arn:aws:iam::123456789012:role/*) only if multiple IAM roles should map to the same Anthropic service account.

Acquire and use the token

Call GetWebIdentityToken with https://api.anthropic.com as the audience, then pass the result to the SDK’s federation credentials through identity_token_provider. Where that option takes a token provider, the SDK calls STS again on each refresh.

import os

import anthropic
import boto3
from anthropic import WorkloadIdentityCredentials


def get_sts_web_identity_token() -> str:
    sts = boto3.client("sts", region_name="us-east-1")
    resp = sts.get_web_identity_token(
        Audience=["https://api.anthropic.com"],
        SigningAlgorithm="RS256",
        DurationSeconds=900,
    )
    return resp["WebIdentityToken"]


client = anthropic.Anthropic(
    credentials=WorkloadIdentityCredentials(
        identity_token_provider=get_sts_web_identity_token,
        federation_rule_id=os.environ["ANTHROPIC_FEDERATION_RULE_ID"],
        organization_id=os.environ["ANTHROPIC_ORGANIZATION_ID"],
        service_account_id=os.environ["ANTHROPIC_SERVICE_ACCOUNT_ID"],
        workspace_id=os.environ.get("ANTHROPIC_WORKSPACE_ID"),
    ),
)

message = client.messages.create(
    model="claude-opus-5-5",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Hello from AWS"}],
)
print(next(block.text for block in message.content if block.type == "text"))

Verify the setup

From inside the workload, exchange an STS-issued token directly and inspect the response:

cURL

JWT=$(aws sts get-web-identity-token \
  --region us-east-1 \
  --audience "https://api.anthropic.com" \
  --signing-algorithm RS256 \
  --duration-seconds 900 \
  --query WebIdentityToken --output text)

curl -sS https://api.anthropic.com/v1/oauth/token \
  -H "content-type: application/json" \
  -d @- <<JSON
{
  "grant_type": "urn:ietf:params:oauth:grant-type:jwt-bearer",
  "assertion": "$JWT",
  "federation_rule_id": "fdrl_...",
  "organization_id": "00000000-0000-0000-0000-000000000000",
  "service_account_id": "svac_...",
  "workspace_id": "wrkspc_..."
}
JSON

A successful exchange returns an access_token starting with sk-ant-oat01- and an expires_in value in seconds. If the exchange fails with the opaque 401 authentication_error response (message Authentication failed), check the authentication history page in the Claude Console for the deny reason. Then see Troubleshoot a failed exchange. The most common AWS-side cause is an iss mismatch. Your account’s STS issuer URL must match the registered issuer_url exactly.

Use EKS projected service-account tokens

If your workload runs in an EKS pod, you can skip the STS call and read a Kubernetes-projected service-account token directly from disk. Kubernetes natively projects an OIDC-compatible token into the pod, and the SDK can read it from a file path. This path has two fewer AWS configuration steps than the STS path but only works inside a pod. The underlying mechanism is the same as in Use WIF with Kubernetes.

This path also requires an EKS cluster with an IAM OIDC provider enabled and kubectl access to the cluster.

Configure your EKS cluster

1
Find your cluster’s OIDC issuer URL
Each EKS cluster has a unique OIDC issuer. Retrieve it with the AWS CLI:
aws eks describe-cluster \ --name <cluster-name> \ --query "cluster.identity.oidc.issuer" \ --output text
The output looks like https://oidc.eks.us-west-2.amazonaws.com/id/6FA42E7BFDE8549CB.... You’ll register this URL as a federation issuer in the next section.

Create the service account and project an Anthropic-audience token

The EKS pod identity webhook detects the eks.amazonaws.com/role-arn annotation and automatically projects a token with aud: sts.amazonaws.com, exposing its path as AWS_WEB_IDENTITY_TOKEN_FILE. That token is for AWS role assumption. For the Anthropic exchange, project a second token with audience: https://api.anthropic.com and mount it at a dedicated path.

apiVersion: v1
kind: ServiceAccount
metadata:
  name: inference-worker
  namespace: inference
  annotations:
    eks.amazonaws.com/role-arn: arn:aws:iam::123456789012:role/inference-worker

apiVersion: v1
kind: Pod
metadata:
  name: inference-worker
  namespace: inference
spec:
  serviceAccountName: inference-worker
  volumes:
    - name: anthropic-token
      projected:
        sources:
          - serviceAccountToken:
              audience: https://api.anthropic.com
              expirationSeconds: 3600
              path: token
  containers:
    - name: app
      image: your-registry/inference-worker:latest
      env:
        - name: ANTHROPIC_IDENTITY_TOKEN_FILE
          value: /var/run/secrets/anthropic.com/token
        - name: ANTHROPIC_FEDERATION_RULE_ID
          value: fdrl_...
        - name: ANTHROPIC_ORGANIZATION_ID
          value: 00000000-0000-0000-0000-000000000000
        - name: ANTHROPIC_SERVICE_ACCOUNT_ID
          value: svac_...
        - name: ANTHROPIC_WORKSPACE_ID  # required when the rule covers multiple workspaces
          value: wrkspc_...
      volumeMounts:
        - name: anthropic-token
          mountPath: /var/run/secrets/anthropic.com
          readOnly: true

3
Note the token’s claim shape
The projected token is a JSON Web Token (JWT) signed by your cluster’s OIDC issuer. Its sub claim follows the Kubernetes convention system:serviceaccount:<namespace>:<service-account-name>:
{ "iss": "https://oidc.eks.us-west-2.amazonaws.com/id/6FA42E7BFDE8549CB...", "sub": "system:serviceaccount:inference:inference-worker", "aud": ["https://api.anthropic.com"], "kubernetes.io": { "namespace": "inference", "serviceaccount": { "name": "inference-worker", "uid": "..." } }, "exp": 1775527120, "iat": 1775523520 }
The serviceAccountToken projection sets aud to https://api.anthropic.com. The separate token that IAM roles for service accounts (IRSA) injects at AWS_WEB_IDENTITY_TOKEN_FILE carries aud: sts.amazonaws.com and is for AWS API calls, not this exchange.

Configure Anthropic

The wizard creates these resources for you. Use the following values whether you enter them in the wizard or send them to the Admin API:

Federation issuer: EKS issuers expose a public JWKS endpoint, so use discovery mode. The issuer URL must exactly match the token’s iss claim. Register one issuer for each cluster.

{
  "name": "prod-eks-uswest2",
  "issuer_url": "https://oidc.eks.us-west-2.amazonaws.com/id/6FA42E7BFDE8549CB...",
  "jwks": { "type": "discovery" }
}

Federation rule: Match the Kubernetes sub claim and the Anthropic audience https://api.anthropic.com. Project a dedicated service-account token with that audience. Don’t reuse the IRSA default sts.amazonaws.com token.

{
  "name": "prod-inference",
  "issuer_id": "fdis_...",
  "match": {
    "subject_prefix": "system:serviceaccount:inference:inference-worker",
    "audience": "https://api.anthropic.com"
  },
  "target": { "type": "service_account", "service_account_id": "svac_..." },
  "workspace_id": "wrkspc_...",
  "oauth_scope": "workspace:developer",
  "token_lifetime_seconds": 600
}

Be as specific as the workload allows. Loosen subject_prefix to system:serviceaccount:inference:* only if every service account in the namespace should map to the same Anthropic service account. The trailing * makes it a prefix match.

Acquire and use the token

Inside the pod, the projected token is at /var/run/secrets/anthropic.com/token (exposed as ANTHROPIC_IDENTITY_TOKEN_FILE in the Pod spec). The SDK gets its identity token from that file and handles the exchange and refresh.

import os

import anthropic
from anthropic import IdentityTokenFile, WorkloadIdentityCredentials

client = anthropic.Anthropic(
    credentials=WorkloadIdentityCredentials(
        identity_token_provider=IdentityTokenFile(
            os.environ["ANTHROPIC_IDENTITY_TOKEN_FILE"]
        ),
        federation_rule_id=os.environ["ANTHROPIC_FEDERATION_RULE_ID"],
        organization_id=os.environ["ANTHROPIC_ORGANIZATION_ID"],
        service_account_id=os.environ["ANTHROPIC_SERVICE_ACCOUNT_ID"],
        workspace_id=os.environ.get("ANTHROPIC_WORKSPACE_ID"),
    ),
)

message = client.messages.create(
    model="claude-opus-5-5",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Hello from EKS"}],
)
print(next(block.text for block in message.content if block.type == "text"))

Verify the setup

From inside the pod, exchange the projected token directly and inspect the response:

cURL

JWT=$(cat "$ANTHROPIC_IDENTITY_TOKEN_FILE")

curl -sS https://api.anthropic.com/v1/oauth/token \
  -H "content-type: application/json" \
  -d @- <<JSON
{
  "grant_type": "urn:ietf:params:oauth:grant-type:jwt-bearer",
  "assertion": "$JWT",
  "federation_rule_id": "$ANTHROPIC_FEDERATION_RULE_ID",
  "organization_id": "$ANTHROPIC_ORGANIZATION_ID",
  "service_account_id": "$ANTHROPIC_SERVICE_ACCOUNT_ID",
  "workspace_id": "$ANTHROPIC_WORKSPACE_ID"
}
JSON

A successful exchange returns an access_token starting with sk-ant-oat01- and an expires_in value in seconds. If the exchange fails with the opaque 401 authentication_error response (message Authentication failed), check the authentication history page in the Claude Console for the deny reason. Then see Troubleshoot a failed exchange. The most common EKS-side cause is the projected token’s aud not matching the rule. Project a token with audience: https://api.anthropic.com, not the IRSA default sts.amazonaws.com.

Scope your rule

Lock the rule’s match block to the narrowest scope that fits your use case:

Pin the full role ARN: Use subject_prefix: "arn:aws:iam::<account>:role/<role-name>" with no trailing * so other roles in the account do not match.
Pin the account ID: Match the aws_account field of the token’s https://sts.amazonaws.com/ claim with a CEL condition. This adds a second check against a misconfigured prefix.
Pin namespace and service account on EKS: Use the exact system:serviceaccount:<namespace>:<name> value with no * after the system:serviceaccount: prefix.
Use a separate rule for each environment: Create distinct rules for production, staging, and development workloads rather than widening one prefix to cover them all.

Next steps

Review the WIF reference for the full credential precedence, profile configuration, and rule matching reference.
For self-managed Kubernetes clusters that aren’t on EKS, see Use WIF with Kubernetes.

Prerequisites

Use STS web identity tokens (recommended)

Configure AWS

Enable outbound web identity federation for the account

Grant the workload’s IAM role permission to call the API

Find your account’s STS issuer URL

Configure Anthropic

Acquire and use the token

Verify the setup

Use EKS projected service-account tokens

Configure your EKS cluster

Find your cluster’s OIDC issuer URL

Create the service account and project an Anthropic-audience token

Note the token’s claim shape

Configure Anthropic

Acquire and use the token

Verify the setup

Scope your rule

Next steps

Prerequisites

Use STS web identity tokens (recommended)

Configure AWS

Configure Anthropic

Acquire and use the token

Verify the setup

Use EKS projected service-account tokens

Configure your EKS cluster

Configure Anthropic

Acquire and use the token

Verify the setup

Scope your rule

Next steps