To obtain an access token using the client credentials flow and then make a request to a resource server using curl, you can follow these steps: 1. First, let's get an access token using the client credentials flow:

bash #!/bin/bash  CLIENT_ID="your_client_id" CLIENT_SECRET="your_client_secret" TOKEN_ENDPOINT="<https://your-project.projects.oryapis.com/oauth2/token>"  # Get the access token ACCESS_TOKEN=$(curl -s -X POST $TOKEN_ENDPOINT \   -H "Content-Type: application/x-www-form-urlencoded" \   -d "grant_type=client_credentials" \   -d "client_id=$CLIENT_ID" \   -d "client_secret=$CLIENT_SECRET" \   | jq -r .access_token)  echo "Access Token: $ACCESS_TOKEN"  # Example request to a resource server RESOURCE_SERVER="<https://api.example.com/protected-resource>"  # Make a request to the resource server using the access token curl -H "Authorization: Bearer $ACCESS_TOKEN" $RESOURCE_SERVER

This script does the following: 1. It sets the

CLIENT_ID

,

CLIENT_SECRET

, and

TOKEN_ENDPOINT

variables. You need to replace these with your actual values. 2. It makes a POST request to the token endpoint to obtain an access token using the client credentials flow. 3. It extracts the access token from the response using

jq

(make sure you have

jq

installed). 4. It prints the access token. 5. Finally, it makes an example request to a resource server using the obtained access token. Make sure to replace

<https://your-project.projects.oryapis.com/oauth2/token>

with your actual token endpoint URL, and

<https://api.example.com/protected-resource>

with the actual resource server endpoint you want to access. This script is based on the information provided in the [Run your own OAuth2 Server](https://www.ory.sh/run-oauth2-server-open-source-api-security/#performing-the-oauth2-client-credentials-flow) and [Try common OAuth2 Grants](https://www.ory.sh/docs/getting-started/ory-network-oauth2) documentation. Remember to set the correct permissions for the script file and run it in a bash environment. [Run your own OAuth2 Server](https://www.ory.sh/run-oauth2-server-open-source-api-security/#performing-the-oauth2-client-credentials-flow) provides more detailed information on setting up and using the OAuth2 server with Ory Hydra.

Based on the curl command you've provided, it seems you're using the client credentials flow to obtain an access token. If you're not getting any response data, there could be a few reasons for this. Let's troubleshoot the issue: 1. Authentication Method: Your curl command is using the

client_secret_basic

authentication method, which is correct and the default method for Ory. However, make sure your client is configured to use this method. As mentioned in the [OAuth2 fundamentals documentation](https://www.ory.sh/docs/oauth2-oidc/overview/oauth2-concepts#creating-oauth2-clients):

The default token_endpoint_auth_method is client_secret_basic, which sends the client_id and client_secret as application/x-www-form-urlencoded encoded in the HTTP Authorization header.

2. Scope: You're requesting the scopes

openid offline offline_access

. Make sure your client is allowed to request these scopes. As per the [OAuth2 fundamentals documentation](https://www.ory.sh/docs/oauth2-oidc/overview/oauth2-concepts#oauth2-scopes-represent-user-consent):

Ory OAuth2 and OpenID Connect has pre-defined OAuth2 scope values:    - offline_access: Include this scope if you want to receive a refresh token    - openid: Include this scope if you want to perform OpenID Connect requests.

However, for the client credentials flow, these scopes might not be applicable as it's typically used for machine-to-machine communication. 3. Error Handling: To better understand what's happening, you should modify your curl command to show the full response, including headers. This will help you see any error messages. Try this modified version:

bash    RESPONSE=$(curl -X POST $TOKEN_URL \      -H "Content-Type: application/x-www-form-urlencoded" \      -H "Authorization: Basic $BASIC_AUTH" \      -d "grant_type=client_credentials" \      -d "scope=openid%20offline%20offline_access" \      -v)     echo "Response: $RESPONSE"

The

-v

flag will show you the verbose output, including headers. 4. Client Configuration: Ensure that your client is properly configured for the client credentials flow. As mentioned in the [Try common OAuth2 Grants documentation](https://www.ory.sh/docs/getting-started/ory-network-oauth2):

Let's create an OAuth2 client capable of performing the OAuth2 client credentials grant:     ory create oauth2-client --project $project_id \        --name "Client Credentials Demo" \        --grant-type client_credentials

Make sure your client was created with the

client_credentials

grant type. 5. Token URL: Double-check that your

$TOKEN_URL

is correct. It should be something like

<https://your-project.projects.oryapis.com/oauth2/token>

. If you're still not getting a response after trying these steps, please provide the verbose output from the modified curl command. This will help in identifying the specific error or issue you're encountering.

A message from kapa.ai

Based on the information provided in the knowledge sources and our previous conversation, I can suggest a few potential reasons why you're not getting any response data from your curl command. Let's go through some troubleshooting steps: 1. Authentication Method: Your curl command is using the

client_secret_basic

authentication method, which is correct and the default method for Ory. However, make sure your client is configured to use this method. As mentioned in the [OAuth2 fundamentals documentation](https://www.ory.sh/docs/oauth2-oidc/overview/oauth2-concepts#creating-oauth2-clients), the default

token_endpoint_auth_method

is

client_secret_basic

. 2. Scope: You're requesting the scopes

openid offline offline_access

. For the client credentials flow, these scopes might not be applicable as it's typically used for machine-to-machine communication. Try removing the scope parameter or using a scope that's specifically allowed for your client. 3. Error Handling: To better understand what's happening, modify your curl command to show the full response, including headers:

bash    RESPONSE=$(curl -X POST $TOKEN_URL \      -H "Content-Type: application/x-www-form-urlencoded" \      -H "Authorization: Basic $BASIC_AUTH" \      -d "grant_type=client_credentials" \      -v)     echo "Response: $RESPONSE"

The

-v

flag will show you the verbose output, including headers. 4. Client Configuration: Ensure that your client is properly configured for the client credentials flow. As mentioned in the [OAuth2 client credentials flow documentation](https://www.ory.sh/docs/oauth2-oidc/client-credentials), you should create a client with the

client_credentials

grant type:

bash    ory create oauth2-client --project $project_id \        --name "Client Credentials Demo" \        --grant-type client_credentials

5. Token URL: Double-check that your

$TOKEN_URL

is correct. It should be something like

<https://your-project.projects.oryapis.com/oauth2/token>

. 6. Client Secret Length: There's an open issue in Ory Hydra ([Github Issue #3581](https://github.com/ory/hydra/issues/3581)) that mentions a potential problem with long client secrets. If your client secret is very long, try creating a new client with a shorter secret. 7. Database Connection: Another open issue ([Github Issue #3671](https://github.com/ory/hydra/issues/3671)) mentions that when the database cannot be connected, the

/oauth2/token

endpoint might return a 401 status code instead of 500. Ensure that your Ory Hydra instance has a stable database connection. If you're still not getting a response after trying these steps, please provide the verbose output from the modified curl command. This will help in identifying the specific error or issue you're encountering.