To add authentication/authorization using client credentials (client ID and secret) with Ory, you can follow these steps: 1. Create an OAuth2 client for client credentials: Use the Ory CLI to create a client with the client credentials grant type:

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

This command will return a client ID and secret [Ory CLI documentation](https://www.ory.sh/docs/getting-started/ory-network-oauth2#client-credentials-grant). 2. Perform the OAuth2 Client Credentials Flow: Use the client ID and secret to obtain an access token:

ory perform client-credentials \   --client-id="$client_id" \   --client-secret="$client_secret" \   --project "$PROJECT_ID"

This will return an access token [Ory CLI documentation](https://www.ory.sh/docs/getting-started/ory-network-oauth2#client-credentials-grant). 3. Use the access token for authentication/authorization: Include the access token in the Authorization header of your API requests:

Authorization: Bearer <access_token>

4. Validate the token: To validate the token on the server-side, you can use token introspection:

ory introspect token $access_token --project "$PROJECT_ID"

This will return metadata about the token, including whether it's active [Ory CLI documentation](https://www.ory.sh/docs/getting-started/ory-network-oauth2#client-credentials-grant). For programmatic use, you can implement these steps using HTTP requests. Here's an example of how to obtain an access token using Basic Authentication [OAuth2 client credentials flow documentation](https://www.ory.sh/docs/oauth2-oidc/client-credentials#basic-authentication):

javascript const clientID = "the-client-id" const clientSecret = "the-secret-id" const basicAuth = bas64_encode(url_encode(clientID) + ":" + url_encode(clientSecret))  const requestOptions = {   method: "POST",   headers: {     Authorization: "Basic " + basicAuth,     "Content-Type": "application/x-www-form-urlencoded",   },   body: "grant_type=client_credentials&scope=read", }  fetch("<https://your-project.projects.oryapis.com/oauth2/token>", requestOptions)   .then((response) => response.json())   .then((data) => console.log(data))

Remember to keep your client secret confidential and use secure methods to store and transmit it.

The process for using client credentials authentication/authorization with self-hosted Ory Hydra is similar to the Ory Network approach, but with some differences in the commands and endpoints. Here's how you can do it with self-hosted Ory: 1. Create an OAuth2 client for client credentials: Use the Ory Hydra CLI to create a client with the client credentials grant type:

docker run --rm -it --network hydraguide oryd/hydra:v2.0.1 \   create oauth2-client \     --endpoint <http://ory-hydra-example--hydra:4445> \     --grant-type client_credentials

This command will return a client ID and secret [Run your own OAuth2 Server](https://www.ory.sh/run-oauth2-server-open-source-api-security/#performing-the-oauth2-client-credentials-flow). 2. Perform the OAuth2 Client Credentials Flow: Use the client ID and secret to obtain an access token:

docker run --rm -it --network hydraguide oryd/hydra:v2.0.1 \   perform client-credentials \     --client-id {INSERT-CLIENT-ID_HERE} \     --client-secret "{INSERT-CLIENT-SECRET-HERE}" \     --endpoint <http://ory-hydra-example--hydra:4444>

This will return an access token [Run your own OAuth2 Server](https://www.ory.sh/run-oauth2-server-open-source-api-security/#performing-the-oauth2-client-credentials-flow). 3. Validate the token: To validate the token on the server-side, you can use token introspection:

docker run --rm -it --network hydraguide oryd/hydra:v2.0.1 \   introspect token \   --endpoint <http://ory-hydra-example--hydra:4445> \     "{INSERT-ACCESS-TOKEN-HERE}"

This will return metadata about the token, including whether it's active [Run your own OAuth2 Server](https://www.ory.sh/run-oauth2-server-open-source-api-security/#performing-the-oauth2-client-credentials-flow). The main differences when using self-hosted Ory Hydra are: 1. You need to use Docker commands to run the Ory Hydra CLI. 2. You need to specify the

--endpoint

flag with the appropriate URLs for your self-hosted Hydra instance. 3. The URLs used for token requests and introspection are specific to your self-hosted setup, rather than the Ory Network URLs. Remember to adjust the network settings, container names, and URLs according to your specific self-hosted Ory Hydra configuration.

To enable client credentials authentication/authorization in a self-hosted Ory Hydra instance, you need to ensure that certain configuration settings are in place. Based on the provided knowledge sources, here are the key Hydra configuration elements needed: 1. OAuth2 Grant Types: Make sure that the

client_credentials

grant type is enabled for your OAuth2 client. This is typically done when creating the client, as shown in the previous example [Run your own OAuth2 Server](https://www.ory.sh/run-oauth2-server-open-source-api-security/#performing-the-oauth2-client-credentials-flow). 2. Token Endpoint Authentication Method: Set the token endpoint authentication method to

client_secret_post

when creating the client. This allows the client to send its credentials in the POST body [Docs > Hydra > Self-hosted > Gitlab Hydra integration](https://www.ory.sh/docs/hydra/self-hosted/gitlab):

--token-endpoint-auth-method client_secret_post

3. Scopes: Define the necessary scopes for your client. Common scopes include

openid

,

offline_access

,

profile

, and

email

[Docs > Hydra > Self-hosted > Gitlab Hydra integration](https://www.ory.sh/docs/hydra/self-hosted/gitlab). 4. URLs Configuration: In your Hydra configuration file (e.g.,

hydra.yml

), ensure that the following URLs are properly set [Docs > Hydra > Self-hosted > Run Ory Hydra in Docker > Deploy Ory Hydra Part 2](https://www.ory.sh/docs/hydra/self-hosted/configure-deploy#deploy-ory-hydra):

yaml
   urls:
     self:
       issuer: <https://localhost:5444/>
     consent: <http://localhost:9020/consent>
     login: <http://localhost:9020/login>

Adjust these URLs according to your specific setup. 5. Secrets: Ensure that you have set a system secret in your configuration [Docs > Hydra > Self-hosted > Run Ory Hydra in Docker > Deploy Ory Hydra Part 2](https://www.ory.sh/docs/hydra/self-hosted/configure-deploy#deploy-ory-hydra):

yaml
   secrets:
     system:
       - your-system-secret-here

6. Database Configuration: Make sure your database connection string (DSN) is properly configured [Docs > Hydra > Self-hosted > Run Ory Hydra in Docker > Deploy Ory Hydra Part 2](https://www.ory.sh/docs/hydra/self-hosted/configure-deploy#deploy-ory-hydra). 7. CORS Configuration (if needed): If you're accessing Hydra from different origins, you might need to configure CORS [Github Issue (open): [With Hdyra]Kratos return null for login_challenge when previous OIDC for the same client not complete. > Original post Part 7](https://github.com/ory/kratos/issues/4024):

yaml
   serve:
     public:
       cors:
         enabled: true
         allowed_origins:
           - <http://localhost:4200>
         allowed_methods:
           - POST
           - GET
         allowed_headers:
           - "Authorization"

To enable client credentials authentication/authorization in a self-hosted Ory Hydra instance, you need to ensure that certain configuration settings are in place. Based on the provided knowledge sources, here are the key Hydra configuration elements needed: 1. OAuth2 Grant Types: Make sure that the

client_credentials

grant type is enabled for your OAuth2 client. This is typically done when creating the client, as shown in the previous example [Run your own OAuth2 Server](https://www.ory.sh/run-oauth2-server-open-source-api-security/#performing-the-oauth2-client-credentials-flow). 2. Token Endpoint Authentication Method: Set the token endpoint authentication method to

client_secret_post

when creating the client. This allows the client to send its credentials in the POST body [Docs > Hydra > Self-hosted > Gitlab Hydra integration](https://www.ory.sh/docs/hydra/self-hosted/gitlab):

--token-endpoint-auth-method client_secret_post

3. Scopes: Define the necessary scopes for your client. Common scopes include

openid

,

offline_access

,

profile

, and

email

[Docs > Hydra > Self-hosted > Gitlab Hydra integration](https://www.ory.sh/docs/hydra/self-hosted/gitlab). 4. URLs Configuration: In your Hydra configuration file (e.g.,

hydra.yml

), ensure that the following URLs are properly set [Docs > Hydra > Self-hosted > Run Ory Hydra in Docker > Deploy Ory Hydra Part 2](https://www.ory.sh/docs/hydra/self-hosted/configure-deploy#deploy-ory-hydra):

yaml    urls:      self:        issuer: <https://localhost:5444/>      consent: <http://localhost:9020/consent>      login: <http://localhost:9020/login>

Adjust these URLs according to your specific setup. 5. Secrets: Ensure that you have set a system secret in your configuration [Docs > Hydra > Self-hosted > Run Ory Hydra in Docker > Deploy Ory Hydra Part 2](https://www.ory.sh/docs/hydra/self-hosted/configure-deploy#deploy-ory-hydra):

yaml    secrets:      system:        - your-system-secret-here

6. Database Configuration: Make sure your database connection string (DSN) is properly configured [Docs > Hydra > Self-hosted > Run Ory Hydra in Docker > Deploy Ory Hydra Part 2](https://www.ory.sh/docs/hydra/self-hosted/configure-deploy#deploy-ory-hydra). 7. CORS Configuration (if needed): If you're accessing Hydra from different origins, you might need to configure CORS [Github Issue (open): [With Hdyra]Kratos return null for login_challenge when previous OIDC for the same client not complete. > Original post Part 7](https://github.com/ory/kratos/issues/4024):

yaml    serve:      public:        cors:          enabled: true          allowed_origins:            - <http://localhost:4200>          allowed_methods:            - POST            - GET          allowed_headers:            - "Authorization"

Remember to adjust these configurations according to your specific needs and environment. After making changes to the configuration, restart your Hydra instance for the changes to take effect.

Based on the knowledge sources provided, I can explain how to use a client ID and secret in an HTTP request for the OAuth2 Client Credentials flow. There are two main methods to authenticate your client: Basic Authentication and Body Authentication. 1. Basic Authentication: This is the most common method. Here's how you can use it in an HTTP request [OAuth2 client credentials flow documentation](https://www.ory.sh/docs/oauth2-oidc/client-credentials#basic-authentication):

javascript const clientID = "your-client-id" const clientSecret = "your-client-secret" const basicAuth = base64_encode(url_encode(clientID) + ":" + url_encode(clientSecret))  const requestOptions = {   method: "POST",   headers: {     Authorization: "Basic " + basicAuth,     "Content-Type": "application/x-www-form-urlencoded",   },   body: "grant_type=client_credentials&scope=read", }  fetch("<https://your-hydra-instance.com/oauth2/token>", requestOptions)   .then((response) => response.json())   .then((data) => console.log(data))

In this method, the client ID and secret are Base64 encoded and sent in the Authorization header. 2. Body Authentication: Alternatively, you can send the client ID and secret in the request body [OAuth2 client credentials flow documentation](https://www.ory.sh/docs/oauth2-oidc/client-credentials#body-authentication):

javascript const clientID = "your-client-id" const clientSecret = "your-client-secret"  const qs = new URLSearchParams() qs.set("grant_type", "client_credentials") qs.set("client_id", clientID) qs.set("client_secret", clientSecret) qs.set("scope", "read")  const requestOptions = {   method: "POST",   headers: { "Content-Type": "application/x-www-form-urlencoded" },   body: qs.toString(), }  fetch("<https://your-hydra-instance.com/oauth2/token>", requestOptions)   .then((response) => response.json())   .then((data) => console.log(data))

In this method, the client ID and secret are included in the request body. Remember to replace

"<http://your-hydra-instance.com|your-hydra-instance.com>"

with the actual URL of your Ory Hydra instance. Also, ensure that your client is configured to use the appropriate authentication method (

client_secret_basic

for Basic Authentication or

client_secret_post

for Body Authentication) when it was created. Both methods will return an access token that you can then use to authenticate subsequent API requests.

To update an identity schema from email to phone using an HTTP request, you'll need to use the Ory Identities API. This process involves updating the identity's traits. Here's how you can do it: 1. First, you'll need to create a new identity schema that includes the phone trait and removes the email trait. This should be done through your Ory project's configuration. 2. Once you have the new schema in place, you can update an existing identity using the

PATCH /admin/identities/{id}

endpoint. Here's how you can do this using an HTTP request:

PATCH /admin/identities/{id} Authorization: Bearer <your_access_token> Content-Type: application/json  [   {     "op": "replace",     "path": "/schema_id",     "value": "new_schema_id_with_phone"   },   {     "op": "replace",     "path": "/traits",     "value": {       "phone": "+1234567890"     }   } ]

Replace

{id}

with the ID of the identity you want to update,

<your_access_token>

with a valid access token,

new_schema_id_with_phone

with the ID of your new schema that includes the phone trait, and

+1234567890

with the actual phone number. This request does two things: 1. It updates the schema ID to the new schema that includes the phone trait. 2. It replaces the entire traits object with a new one that only includes the phone number. [Ory API Reference](https://www.ory.sh/docs/reference/api) provides more details on this endpoint. 3. To verify that the phone number is added as a verifiable address, you can include the following in your PATCH request:

json {   "op": "add",   "path": "/verifiable_addresses",   "value": [     {       "value": "+1234567890",       "verified": false,       "via": "sms",       "status": "pending"     }   ] }

This will add the phone number as a verifiable address [Ory API Reference](https://www.ory.sh/docs/reference/api). 4. After updating the identity, you may want to trigger a verification flow for the new phone number. You can do this by creating a verification flow and then submitting it with the verification code sent to the phone number. Remember to update your identity schema to include the necessary Ory extensions for phone verification:

json "phone": {   "type": "string",   "format": "tel",   "title": "Phone number",   "<http://ory.sh/kratos|ory.sh/kratos>": {     "credentials": {       "password": {         "identifier": true       },       "code": {         "identifier": true,         "via": "sms"       }     },     "verification": {       "via": "sms"     }   } }

This configuration allows the phone number to be used for authentication and verification [Docs > Kratos > Passwordless > Email and SMS one-time-code authentication > Custom identity schema](https://www.ory.sh/docs/kratos/passwordless/one-time-code#custom-identity-schema). Please note that changing the primary identifier (from email to phone) for existing users should be done carefully, ensuring that users can still access their accounts after the change.

Based on the information provided in the knowledge sources and your question, it appears that you're encountering an issue with the

oauth2_client_credentials

handler configuration in Oathkeeper. Let me help you with the correct configuration and explain why you might be getting a 404 error. The

oauth2_client_credentials

handler in Oathkeeper is used to validate OAuth2 client credentials. Here's how you should configure it in your access rules: 1. First, make sure you're using the correct token URL. The URL you provided (`http://hydra:4445/oauth2/token`) is incorrect. The OAuth2 token endpoint typically uses port 4444, not 4445. Port 4445 is usually used for Hydra's admin API. Here's how you should configure it [Docs > Oathkeeper > Pipeline > Authenticators](https://www.ory.sh/docs/oathkeeper/pipeline/authn#oauth2_client_credentials):

yaml authenticators:   - handler: oauth2_client_credentials     config:       token_url: <http://hydra:4444/oauth2/token>

2. You may also need to configure additional options. Here's a more comprehensive example:

yaml authenticators:   - handler: oauth2_client_credentials     config:       token_url: <http://hydra:4444/oauth2/token>       scope_strategy: exact       required_scope:         - read         - write       retry:         max_delay: 300ms         give_up_after: 2s

3. If you're using Docker, make sure that the network settings are correct and that Oathkeeper can reach Hydra using the hostname "hydra". 4. If you're still getting a 404 error, it could be because: - The Hydra service is not running or not reachable. - The OAuth2 server is not properly configured. - There's a network issue between Oathkeeper and Hydra. 5. You can also add some debug headers to get more information:

yaml introspection_request_headers:   X-Forwarded-Proto: https

6. If you need to authenticate the request to the token endpoint, you can use the

pre_authorization

configuration:

yaml pre_authorization:   enabled: true   client_id: some_id   client_secret: some_secret   scope:     - introspect   token_url: <http://hydra:4444/oauth2/token>

Remember to adjust these configurations according to your specific setup and requirements. If you continue to face issues, you may want to check the Hydra logs for any errors, ensure that the Hydra service is running correctly, and verify that the network configuration allows Oathkeeper to communicate with Hydra. [Docs > Oathkeeper > Pipeline > Authenticators](https://www.ory.sh/docs/oathkeeper/pipeline/authn#oauth2_client_credentials)

Based on the error message you're receiving, it appears that the client authentication is failing when trying to create a new identity using an HTTP request with client_id and client_secret. This suggests that there might be some additional configuration or steps needed. Let's go through some potential solutions: 1. Verify Client Credentials: Make sure that the client_id and client_secret you're using are correct and properly configured in your Ory Hydra instance. 2. Check Client Authentication Method: Ensure that the client is configured to use the correct authentication method. As mentioned earlier, you should set the token endpoint authentication method when creating the client [Docs > Hydra > Self-hosted > Gitlab Hydra integration](https://www.ory.sh/docs/hydra/self-hosted/gitlab):

--token-endpoint-auth-method client_secret_post

3. Grant Types: Verify that the client is allowed to use the client_credentials grant type. When creating the client, make sure to include this grant type:

--grant-type client_credentials

4. Scopes: Ensure that the client has the necessary scopes to create identities. You may need to add specific scopes when creating the client, for example:

--scope create_identities

5. API Endpoint: Make sure you're using the correct API endpoint for creating identities. For Ory Kratos, it should be something like:

POST /admin/identities

6. Access Token: Before making the request to create an identity, you need to obtain an access token using the client credentials. The process should be: a. Get an access token:

POST /oauth2/token    Content-Type: application/x-www-form-urlencoded     grant_type=client_credentials&client_id=your_client_id&client_secret=your_client_secret

b. Use the obtained access token to create the identity:

POST /admin/identities    Authorization: Bearer <access_token>    Content-Type: application/json     {      "schema_id": "your_schema_id",      "traits": {        // Your identity traits here      }    }

7. Hydra Admin API: Ensure that your Hydra admin API is properly configured and accessible. The admin API typically runs on a different port (usually 4445) than the public API. 8. Network and Firewall: Check that there are no network or firewall issues preventing communication between your client and the Ory services. If you've verified all these points and are still encountering issues, you may need to check the logs of your Ory Hydra and Kratos instances for more detailed error messages. Additionally, ensure that your self-hosted setup is properly configured and all services are running correctly. Remember, when working with sensitive operations like identity creation, it's crucial to use secure methods for storing and transmitting client credentials and access tokens.

I apologize for the confusion regarding the Docker Compose command. You're right that there seems to be an issue with the command mentioned in the documentation. Let me provide you with the correct command and address your concerns about the

create_identities

scope. Regarding the Docker Compose command, the correct version should be:

docker-compose -f quickstart.yml exec hydra \
    hydra create client \
    --endpoint <http://127.0.0.1:4445> \
    --format json \
    --grant-type client_credentials \
    --response-type token \
    --scope create_identities

The

--id

flag was incorrectly included in the previous example. This command will create a new OAuth2 client with the

client_credentials

grant type and the

create_identities

scope. [Run your own OAuth2 Server](https://www.ory.sh/run-oauth2-server-open-source-api-security/#performing-the-oauth2-client-credentials-flow) As for the issue with the

create_identities

scope, adding it manually to the database might not be sufficient. The scope needs to be properly associated with the OAuth2 client and recognized by the authorization server. Here are some steps you can take to troubleshoot and fix this issue: 1. Verify client configuration: Make sure the client is properly configured with the

create_identities

scope. You can check this by listing the client details:

docker-compose -f quickstart.yml exec hydra \
       hydra get client <client_id> \
       --endpoint <http://127.0.0.1:4445>

Ensure that the

create_identities

scope is listed in the client's allowed scopes. 2. Update client configuration: If the scope is not present, you can update the client configuration:

docker-compose -f quickstart.yml exec hydra \
       hydra update client <client_id> \
       --endpoint <http://127.0.0.1:4445> \
       --scope create_identities

3. Check Hydra configuration: Ensure that the

create_identities

scope is recognized by Hydra. You might need to add it to your Hydra configuration file (usually

hydra.yml

):

yaml
   oauth2:
     scopes:
       supported:
         - create_identities

4. Restart Hydra: After making changes to the configuration, restart your Hydra instance:

docker-compose -f quickstart.yml restart hydra

5. Request the correct scope: When making the token request, explicitly include the

create_identities

scope:

POST /oauth2/token
   Content-Type: application/x-www-form-urlencoded

   grant_type=client_credentials&client_id=your_client_id&client_secret=your_client_secret&scope=create_identities

6. Check Hydra logs: Examine the Hydra logs for any error messages or warnings related to scopes or client authentication:

docker-compose -f quickstart.yml logs hydra

I apologize for the confusion regarding the Docker Compose command. You're right that there seems to be an issue with the command mentioned in the documentation. Let me provide you with the correct command and address your concerns about the

create_identities

scope. Regarding the Docker Compose command, the correct version should be:

docker-compose -f quickstart.yml exec hydra \     hydra create client \     --endpoint <http://127.0.0.1:4445> \     --format json \     --grant-type client_credentials \     --response-type token \     --scope create_identities

The

--id

flag was incorrectly included in the previous example. This command will create a new OAuth2 client with the

client_credentials

grant type and the

create_identities

scope. [Run your own OAuth2 Server](https://www.ory.sh/run-oauth2-server-open-source-api-security/#performing-the-oauth2-client-credentials-flow) As for the issue with the

create_identities

scope, adding it manually to the database might not be sufficient. The scope needs to be properly associated with the OAuth2 client and recognized by the authorization server. Here are some steps you can take to troubleshoot and fix this issue: 1. Verify client configuration: Make sure the client is properly configured with the

create_identities

scope. You can check this by listing the client details:

docker-compose -f quickstart.yml exec hydra \        hydra get client <client_id> \        --endpoint <http://127.0.0.1:4445>

Ensure that the

create_identities

scope is listed in the client's allowed scopes. 2. Update client configuration: If the scope is not present, you can update the client configuration:

docker-compose -f quickstart.yml exec hydra \        hydra update client <client_id> \        --endpoint <http://127.0.0.1:4445> \        --scope create_identities

3. Check Hydra configuration: Ensure that the

create_identities

scope is recognized by Hydra. You might need to add it to your Hydra configuration file (usually

hydra.yml

):

yaml    oauth2:      scopes:        supported:          - create_identities

4. Restart Hydra: After making changes to the configuration, restart your Hydra instance:

docker-compose -f quickstart.yml restart hydra

5. Request the correct scope: When making the token request, explicitly include the

create_identities

scope:

POST /oauth2/token    Content-Type: application/x-www-form-urlencoded     grant_type=client_credentials&client_id=your_client_id&client_secret=your_client_secret&scope=create_identities

6. Check Hydra logs: Examine the Hydra logs for any error messages or warnings related to scopes or client authentication:

docker-compose -f quickstart.yml logs hydra

If you're still encountering issues after trying these steps, there might be a more complex configuration problem or a mismatch between your Hydra version and the documentation. In that case, you may need to consult the specific version documentation for your Hydra installation or reach out to the Ory community for further assistance.

I apologize for the confusion in my previous response. You're right, and thank you for pointing out this error. The configuration I suggested is not valid for Ory Hydra v2.2.0. Let me provide you with the correct information based on the latest Hydra version. In Ory Hydra v2.2.0, the configuration structure for OAuth2 scopes has changed. The

oauth2.scopes.supported

configuration is no longer used. Instead, scopes are typically defined when creating or updating OAuth2 clients. To resolve this issue and properly configure scopes for your Hydra instance, follow these steps: 1. Remove the invalid configuration from your

hydra.yml

file. Delete or comment out the following section:

yaml    # oauth2:    #   scopes:    #     supported:    #       - create_identities

2. Instead of configuring scopes globally, you should define them when creating or updating your OAuth2 client. Use the Hydra CLI to create or update a client with the required scopes:

docker-compose -f quickstart.yml exec hydra \        hydra create client \        --endpoint <http://127.0.0.1:4445> \        --format json \        --grant-type client_credentials \        --response-type token \        --scope create_identities

This command creates a new client with the

create_identities

scope. If you want to update an existing client, use the

update client

command instead. 3. Restart your Hydra container after making these changes:

docker-compose -f quickstart.yml restart hydra

4. When making token requests, explicitly include the

create_identities

scope:

POST /oauth2/token    Content-Type: application/x-www-form-urlencoded     grant_type=client_credentials&client_id=your_client_id&client_secret=your_client_secret&scope=create_identities

Remember, in Ory Hydra v2.2.0, scopes are managed at the client level rather than globally in the Hydra configuration. This approach provides more flexibility and security by allowing you to control which clients have access to specific scopes. If you continue to experience issues, please check the [Ory Hydra documentation](https://www.ory.sh/docs/hydra) for the most up-to-date information on configuration and scope management for your specific version.

Certainly! I'll update the POST request to use a JSON payload instead of the URL-encoded format. Here's the updated version of the token request using JSON:

POST /oauth2/token Content-Type: application/json Accept: application/json  {   "grant_type": "client_credentials",   "client_id": "your_client_id",   "client_secret": "your_client_secret",   "scope": "create_identities" }

This JSON format is equivalent to the previous URL-encoded version. Make sure to replace

"your_client_id"

and

"your_client_secret"

with your actual client credentials. When using this format, ensure that your OAuth2 server (Ory Hydra in this case) is configured to accept JSON payloads for token requests. Most modern OAuth2 servers, including Ory Hydra, support both URL-encoded and JSON formats for token requests. Remember to set the

Content-Type

header to

application/json

to indicate that you're sending a JSON payload. The

Accept

header is set to

application/json

to request a JSON response. This JSON format can be more convenient when working with programming languages that have built-in JSON support, making it easier to construct and parse the request and response bodies.

Based on the error message you're receiving, it appears that the OAuth2 token endpoint is not found or not accessible. This 404 error suggests that the URL you're using to fetch the token is incorrect or the service is not running at the expected location. Let's troubleshoot this issue: 1. Check the token URL: Make sure you're using the correct URL for the token endpoint. For Ory Hydra, the default token endpoint is typically:

<http://hydra:4444/oauth2/token>

If you're running Hydra locally or with a different configuration, adjust the hostname and port accordingly. 2. Verify Hydra is running: Ensure that your Ory Hydra instance is up and running. You can check this by running:

docker-compose -f quickstart.yml ps

Look for the Hydra service and make sure it's in the "Up" state. 3. Check network configuration: If you're using Docker, ensure that the network is properly configured and that the service making the request can reach the Hydra container. You might need to use the internal Docker network name instead of

hydra

in the URL. 4. Verify ports: Make sure that the port you're using (4444 for the public API) is correctly exposed and mapped in your Docker configuration. 5. Check Hydra logs: Examine the Hydra logs for any error messages or warnings:

docker-compose -f quickstart.yml logs hydra

6. Try using the container IP: If you're having trouble with the hostname resolution, try using the container's IP address instead. You can find it using:

docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' hydra

Then use this IP in your token URL. 7. Ensure correct endpoint: Double-check that you're not accidentally using the admin API endpoint (usually on port 4445) instead of the public API endpoint (usually on port 4444) for token requests. 8. Test with curl: Try making a request using curl to isolate if it's an issue with your application or the Hydra setup:

curl -X POST \      <http://hydra:4444/oauth2/token> \      -H 'Content-Type: application/x-www-form-urlencoded' \      -H 'Authorization: Basic <base64_encoded_client_id:client_secret>' \      -d 'grant_type=client_credentials&scope=create_identities'

Replace

<base64_encoded_client_id:client_secret>

with the Base64-encoded string of your

client_id:client_secret

. If you've verified all these points and are still encountering the 404 error, there might be an issue with your Hydra configuration or deployment. In that case, you may need to review your entire Hydra setup, including the Docker Compose file and any custom configurations you've applied. [Run your own OAuth2 Server](https://www.ory.sh/run-oauth2-server-open-source-api-security/#performing-the-oauth2-client-credentials-flow) Remember to always use secure methods for handling client credentials and access tokens, especially in production environments.

Based on the new information you've provided, it seems that the Hydra service is running (as confirmed by the

/health/alive

endpoint), but the token endpoint is not accepting the request method you're using. Let's address this "Method Not Allowed" (405) error: 1. Verify the HTTP method: The OAuth2 token endpoint typically expects a POST request. Make sure you're using the POST method when making the token request. Here's an example of how the request should look:

POST /oauth2/token HTTP/1.1
   Host: hydra:4444
   Content-Type: application/x-www-form-urlencoded
   Authorization: Basic <base64_encoded_client_id:client_secret>

   grant_type=client_credentials&scope=create_identities

2. Check the Content-Type header: Ensure that you're using the correct Content-Type header. For token requests, it should be

application/x-www-form-urlencoded

. 3. Use the correct endpoint: Confirm that you're using the correct endpoint for token requests. For Ory Hydra, it should be:

<http://hydra:4444/oauth2/token>

4. Verify client authentication method: Make sure your client is configured to use the correct token endpoint authentication method. You can check this using the Hydra CLI:

docker-compose -f quickstart.yml exec hydra \
       hydra get client <your_client_id> \
       --endpoint <http://127.0.0.1:4445>

Look for the

token_endpoint_auth_method

field. It should be either

client_secret_basic

or

client_secret_post

. 5. Try both authentication methods: If you're unsure about the authentication method, try both: a. Basic Auth:

POST /oauth2/token HTTP/1.1
   Host: hydra:4444
   Authorization: Basic <base64_encoded_client_id:client_secret>
   Content-Type: application/x-www-form-urlencoded

   grant_type=client_credentials&scope=create_identities

b. Form Post:

POST /oauth2/token HTTP/1.1
   Host: hydra:4444
   Content-Type: application/x-www-form-urlencoded

   grant_type=client_credentials&client_id=<your_client_id>&client_secret=<your_client_secret>&scope=create_identities

6. Check Hydra configuration: Review your Hydra configuration to ensure that the token endpoint is properly set up. Look for any custom configurations that might affect the token endpoint behavior. 7. Examine Hydra logs: Check the Hydra logs for any specific error messages related to the token endpoint:

docker-compose -f quickstart.yml logs hydra

8. Verify OAuth2 client configuration: Ensure that the OAuth2 client is properly configured with the correct grant types and scopes. You can update the client if needed:

docker-compose -f quickstart.yml exec hydra \
       hydra update client <your_client_id> \
       --endpoint <http://127.0.0.1:4445> \
       --grant-type client_credentials \
       --scope create_identities

Based on the new information you've provided, it seems that the Hydra service is running (as confirmed by the

/health/alive

endpoint), but the token endpoint is not accepting the request method you're using. Let's address this "Method Not Allowed" (405) error: 1. Verify the HTTP method: The OAuth2 token endpoint typically expects a POST request. Make sure you're using the POST method when making the token request. Here's an example of how the request should look:

POST /oauth2/token HTTP/1.1    Host: hydra:4444    Content-Type: application/x-www-form-urlencoded    Authorization: Basic <base64_encoded_client_id:client_secret>     grant_type=client_credentials&scope=create_identities

2. Check the Content-Type header: Ensure that you're using the correct Content-Type header. For token requests, it should be

application/x-www-form-urlencoded

. 3. Use the correct endpoint: Confirm that you're using the correct endpoint for token requests. For Ory Hydra, it should be:

<http://hydra:4444/oauth2/token>

4. Verify client authentication method: Make sure your client is configured to use the correct token endpoint authentication method. You can check this using the Hydra CLI:

docker-compose -f quickstart.yml exec hydra \        hydra get client <your_client_id> \        --endpoint <http://127.0.0.1:4445>

Look for the

token_endpoint_auth_method

field. It should be either

client_secret_basic

or

client_secret_post

. 5. Try both authentication methods: If you're unsure about the authentication method, try both: a. Basic Auth:

POST /oauth2/token HTTP/1.1    Host: hydra:4444    Authorization: Basic <base64_encoded_client_id:client_secret>    Content-Type: application/x-www-form-urlencoded     grant_type=client_credentials&scope=create_identities

b. Form Post:

POST /oauth2/token HTTP/1.1    Host: hydra:4444    Content-Type: application/x-www-form-urlencoded     grant_type=client_credentials&client_id=<your_client_id>&client_secret=<your_client_secret>&scope=create_identities

6. Check Hydra configuration: Review your Hydra configuration to ensure that the token endpoint is properly set up. Look for any custom configurations that might affect the token endpoint behavior. 7. Examine Hydra logs: Check the Hydra logs for any specific error messages related to the token endpoint:

docker-compose -f quickstart.yml logs hydra

8. Verify OAuth2 client configuration: Ensure that the OAuth2 client is properly configured with the correct grant types and scopes. You can update the client if needed:

docker-compose -f quickstart.yml exec hydra \        hydra update client <your_client_id> \        --endpoint <http://127.0.0.1:4445> \        --grant-type client_credentials \        --scope create_identities

If you've verified all these points and are still encountering the 405 error, there might be an issue with your Hydra setup or a misconfiguration in your reverse proxy (if you're using one). In that case, you may need to review your entire Hydra deployment, including network configurations and any intermediary services between your client and Hydra. [Docs > Hydra > Debug > Client auth fails because Wrong token_endpoint_auth_method](https://www.ory.sh/docs/hydra/debug/token-endpoint-auth-method) Remember to always use secure methods for handling client credentials and access tokens, especially in production environments.

Based on the error message you're receiving, it appears that the request body is empty when making the token request. This is a common issue when the request is not properly formatted. Let's address this problem: 1. Ensure that you're sending the request body correctly. For a client credentials grant, your request should look like this:

POST /oauth2/token HTTP/1.1 Host: hydra:4444 Content-Type: application/x-www-form-urlencoded Authorization: Basic <base64_encoded_client_id:client_secret>  grant_type=client_credentials&scope=create_identities

2. Make sure that the

Content-Type

header is set to

application/x-www-form-urlencoded

. This is crucial for Hydra to properly parse the request body. 3. Double-check that you're actually sending the request body. Some HTTP clients or libraries might not send the body by default for POST requests. 4. If you're using a programming language or library to make the request, ensure that you're properly setting the request body. For example, in JavaScript with fetch:

javascript fetch('<http://hydra:4444/oauth2/token>', {   method: 'POST',   headers: {     'Content-Type': 'application/x-www-form-urlencoded',     'Authorization': 'Basic ' + btoa(client_id + ':' + client_secret)   },   body: 'grant_type=client_credentials&scope=create_identities' })

5. If you're using cURL for testing, make sure you're including the

-d

flag to send the data:

curl -X POST \   <http://hydra:4444/oauth2/token> \   -H 'Content-Type: application/x-www-form-urlencoded' \   -H 'Authorization: Basic <base64_encoded_client_id:client_secret>' \   -d 'grant_type=client_credentials&scope=create_identities'

6. Verify that your client is configured to use the correct token endpoint authentication method. If it's set to

client_secret_post

, you should include the client credentials in the request body instead of the Authorization header:

grant_type=client_credentials&scope=create_identities&client_id=your_client_id&client_secret=your_client_secret

7. If you're still having issues, try explicitly setting the

Content-Length

header with the correct length of your request body. Remember, the "invalid_request" error with the message "The POST body can not be empty" specifically indicates that Hydra is receiving a request with an empty body. This suggests that the problem is likely in how you're constructing and sending the request, rather than with the Hydra configuration itself. If you continue to face issues after trying these solutions, please provide more details about how you're making the request (e.g., the code or command you're using), and I can offer more specific guidance. [Docs > Hydra > Debug > Client auth fails because Wrong token_endpoint_auth_method](https://www.ory.sh/docs/hydra/debug/token-endpoint-auth-method)

Based on the error message you're receiving, it appears that there's an issue with client authentication. Even though you've confirmed that the client exists in the database, there could be several reasons for this "invalid_client" error. Let's troubleshoot this issue step by step: 1. Verify client credentials: Double-check that you're using the correct client_id and client_secret. Even a small typo can cause this error. 2. Check client authentication method: Ensure that you're using the correct authentication method for your client. You can verify this using the Hydra CLI:

docker-compose -f quickstart.yml exec hydra \
       hydra get client <your_client_id> \
       --endpoint <http://127.0.0.1:4445>

Look for the

token_endpoint_auth_method

field. It should be either

client_secret_basic

or

client_secret_post

. 3. Use the correct authentication method: Based on the `token_endpoint_auth_method`: - For `client_secret_basic`:

POST /oauth2/token HTTP/1.1
     Host: hydra:4444
     Authorization: Basic <base64_encoded_client_id:client_secret>
     Content-Type: application/x-www-form-urlencoded

     grant_type=client_credentials&scope=create_identities

- For `client_secret_post`:

POST /oauth2/token HTTP/1.1
     Host: hydra:4444
     Content-Type: application/x-www-form-urlencoded

     grant_type=client_credentials&client_id=<your_client_id>&client_secret=<your_client_secret>&scope=create_identities

4. Check client status: Ensure that the client is active and not disabled. You can check this in the client configuration. 5. Verify grant types: Make sure that the client is allowed to use the

client_credentials

grant type. You can check this in the client configuration as well. 6. Encode credentials properly: If using Basic Authentication, ensure that the client_id and client_secret are properly Base64 encoded. The format should be:

Base64(url_encode(client_id) + ":" + url_encode(client_secret))

7. Check for special characters: If your client_id or client_secret contains special characters, ensure they are properly URL-encoded. 8. Verify Hydra configuration: Check your Hydra configuration to ensure that the token endpoint is properly set up and that there are no restrictions that might be causing this error. 9. Examine Hydra logs: Look at the Hydra logs for more detailed error messages:

docker-compose -f quickstart.yml logs hydra

10. Try recreating the client: If all else fails, try deleting and recreating the OAuth2 client: ``` docker-compose -f quickstart.yml exec hydra \ hydra delete client <your_client_id> \ --endpoint http://127.0.0.1:4445

Based on the error message you're receiving, it appears that there's an issue with client authentication. Even though you've confirmed that the client exists in the database, there could be several reasons for this "invalid_client" error. Let's troubleshoot this issue step by step: 1. Verify client credentials: Double-check that you're using the correct client_id and client_secret. Even a small typo can cause this error. 2. Check client authentication method: Ensure that you're using the correct authentication method for your client. You can verify this using the Hydra CLI:

docker-compose -f quickstart.yml exec hydra \        hydra get client <your_client_id> \        --endpoint <http://127.0.0.1:4445>

Look for the

token_endpoint_auth_method

field. It should be either

client_secret_basic

or

client_secret_post

. 3. Use the correct authentication method: Based on the `token_endpoint_auth_method`: - For `client_secret_basic`:

POST /oauth2/token HTTP/1.1      Host: hydra:4444      Authorization: Basic <base64_encoded_client_id:client_secret>      Content-Type: application/x-www-form-urlencoded       grant_type=client_credentials&scope=create_identities

- For `client_secret_post`:

POST /oauth2/token HTTP/1.1      Host: hydra:4444      Content-Type: application/x-www-form-urlencoded       grant_type=client_credentials&client_id=<your_client_id>&client_secret=<your_client_secret>&scope=create_identities

4. Check client status: Ensure that the client is active and not disabled. You can check this in the client configuration. 5. Verify grant types: Make sure that the client is allowed to use the

client_credentials

grant type. You can check this in the client configuration as well. 6. Encode credentials properly: If using Basic Authentication, ensure that the client_id and client_secret are properly Base64 encoded. The format should be:

Base64(url_encode(client_id) + ":" + url_encode(client_secret))

7. Check for special characters: If your client_id or client_secret contains special characters, ensure they are properly URL-encoded. 8. Verify Hydra configuration: Check your Hydra configuration to ensure that the token endpoint is properly set up and that there are no restrictions that might be causing this error. 9. Examine Hydra logs: Look at the Hydra logs for more detailed error messages:

docker-compose -f quickstart.yml logs hydra

10. Try recreating the client: If all else fails, try deleting and recreating the OAuth2 client:

docker-compose -f quickstart.yml exec hydra \         hydra delete client <your_client_id> \         --endpoint <http://127.0.0.1:4445>      docker-compose -f quickstart.yml exec hydra \         hydra create client \         --endpoint <http://127.0.0.1:4445> \         --grant-type client_credentials \         --response-type token \         --scope create_identities

If you've verified all these points and are still encountering the 401 error, there might be an issue with your Hydra setup or database configuration. In that case, you may need to review your entire Hydra deployment, including database connections and any custom configurations you've applied. [Docs > Hydra > Debug > Client auth fails because Wrong token_endpoint_auth_method](https://www.ory.sh/docs/hydra/debug/token-endpoint-auth-method) Remember to always use secure methods for handling client credentials and access tokens, especially in production environments.

When I mentioned "client configuration" in the "Check client status" step, I was referring to the OAuth2 client settings stored in Ory Hydra. Let me clarify this in more detail: In Ory Hydra, each OAuth2 client has a set of configuration parameters that define its behavior and permissions. These settings are typically stored in Hydra's database and can be viewed or modified using the Hydra CLI or API. To check the client configuration, including its status, you can use the Hydra CLI as follows:

docker-compose -f quickstart.yml exec hydra \     hydra get client <your_client_id> \     --endpoint <http://127.0.0.1:4445>

This command will return the full configuration for the specified client [Run your own OAuth2 Server](https://www.ory.sh/run-oauth2-server-open-source-api-security/#performing-the-oauth2-client-credentials-flow). In the output, you should look for fields that indicate the client's status, such as: 1. `client_secret_expires_at`: If this is set to a non-zero value, check if the secret has expired. 2. `grant_types`: Ensure that

client_credentials

is listed here. 3. `token_endpoint_auth_method`: This should match the authentication method you're using (e.g.,

client_secret_basic

or

client_secret_post

). 4. `scope`: Check if the scopes you're requesting (like

create_identities

) are listed here. While Hydra doesn't have an explicit "active" or "inactive" status for clients, a client could be effectively disabled if its configuration doesn't allow it to authenticate or perform the actions you're attempting. If you need to modify the client configuration, you can use the

hydra update client

command. For example:

docker-compose -f quickstart.yml exec hydra \     hydra update client <your_client_id> \     --endpoint <http://127.0.0.1:4445> \     --grant-type client_credentials \     --scope create_identities

This command would update the client to ensure it has the

client_credentials

grant type and the

create_identities

scope [Docs > Hydra > Self-hosted > Gitlab Hydra integration](https://www.ory.sh/docs/hydra/self-hosted/gitlab). By reviewing and potentially updating these configuration settings, you can ensure that your client is properly set up to authenticate and perform the actions you need.

Based on the information you've provided, it seems that there's a mismatch between the client authentication method you're using in your request and the method configured for your OAuth2 client in Ory Hydra. Let's address this issue step by step: 1. Client Configuration: You've confirmed that the client is recognized by the service and that you've set the

token_endpoint_auth_method

back to

client_secret_basic

. This is good, as it matches the error message you received earlier. 2. Request Format: Since you're using

client_secret_basic

, your token request should look like this:

POST /oauth2/token HTTP/1.1
   Host: hydra:4444
   Authorization: Basic <base64_encoded_client_id:client_secret>
   Content-Type: application/x-www-form-urlencoded

   grant_type=client_credentials&scope=create_identities

Make sure you're not including the client_id and client_secret in the request body when using

client_secret_basic

. 3. Authorization Header: Double-check that you're correctly formatting the Authorization header. The value should be "Basic" followed by a space and then the Base64-encoded string of your client_id and client_secret separated by a colon. For example:

Authorization: Basic base64_encode(url_encode(client_id) + ":" + url_encode(client_secret))

[Docs > Hydra > Debug > Client auth fails because Wrong token_endpoint_auth_method](https://www.ory.sh/docs/hydra/debug/token-endpoint-auth-method) 4. URL Encoding: Ensure that your client_id and client_secret are properly URL-encoded before Base64 encoding them for the Authorization header. This is especially important if they contain special characters. 5. Verify Client Configuration: Double-check the client configuration one more time using the Hydra CLI:

docker-compose -f quickstart.yml exec hydra \
       hydra get client <your_client_id> \
       --endpoint <http://127.0.0.1:4445>

Confirm that

token_endpoint_auth_method

is set to

client_secret_basic

and that the client_secret hasn't changed. 6. Clear Cache: If you've made changes to the client configuration, there might be some caching involved. Try restarting your Hydra instance:

docker-compose -f quickstart.yml restart hydra

7. Check Hydra Logs: Examine the Hydra logs for any additional error messages or warnings that might provide more insight:

docker-compose -f quickstart.yml logs hydra

8. Test with cURL: To isolate any potential issues with your application code, try making a request using cURL:

curl -X POST \
     <http://hydra:4444/oauth2/token> \
     -H 'Content-Type: application/x-www-form-urlencoded' \
     -H 'Authorization: Basic <base64_encoded_client_id:client_secret>' \
     -d 'grant_type=client_credentials&scope=create_identities'

Replace

<base64_encoded_client_id:client_secret>

with the actual Base64-encoded string of your client_id and client_secret.

Based on the information you've provided, it seems that there's a mismatch between the client authentication method you're using in your request and the method configured for your OAuth2 client in Ory Hydra. Let's address this issue step by step: 1. Client Configuration: You've confirmed that the client is recognized by the service and that you've set the

token_endpoint_auth_method

back to

client_secret_basic

. This is good, as it matches the error message you received earlier. 2. Request Format: Since you're using

client_secret_basic

, your token request should look like this:

POST /oauth2/token HTTP/1.1    Host: hydra:4444    Authorization: Basic <base64_encoded_client_id:client_secret>    Content-Type: application/x-www-form-urlencoded     grant_type=client_credentials&scope=create_identities

Make sure you're not including the client_id and client_secret in the request body when using

client_secret_basic

. 3. Authorization Header: Double-check that you're correctly formatting the Authorization header. The value should be "Basic" followed by a space and then the Base64-encoded string of your client_id and client_secret separated by a colon. For example:

Authorization: Basic base64_encode(url_encode(client_id) + ":" + url_encode(client_secret))

[Docs > Hydra > Debug > Client auth fails because Wrong token_endpoint_auth_method](https://www.ory.sh/docs/hydra/debug/token-endpoint-auth-method) 4. URL Encoding: Ensure that your client_id and client_secret are properly URL-encoded before Base64 encoding them for the Authorization header. This is especially important if they contain special characters. 5. Verify Client Configuration: Double-check the client configuration one more time using the Hydra CLI:

docker-compose -f quickstart.yml exec hydra \        hydra get client <your_client_id> \        --endpoint <http://127.0.0.1:4445>

Confirm that

token_endpoint_auth_method

is set to

client_secret_basic

and that the client_secret hasn't changed. 6. Clear Cache: If you've made changes to the client configuration, there might be some caching involved. Try restarting your Hydra instance:

docker-compose -f quickstart.yml restart hydra

7. Check Hydra Logs: Examine the Hydra logs for any additional error messages or warnings that might provide more insight:

docker-compose -f quickstart.yml logs hydra

8. Test with cURL: To isolate any potential issues with your application code, try making a request using cURL:

curl -X POST \      <http://hydra:4444/oauth2/token> \      -H 'Content-Type: application/x-www-form-urlencoded' \      -H 'Authorization: Basic <base64_encoded_client_id:client_secret>' \      -d 'grant_type=client_credentials&scope=create_identities'

Replace

<base64_encoded_client_id:client_secret>

with the actual Base64-encoded string of your client_id and client_secret. If you've verified all these points and are still encountering the 401 error, there might be an underlying issue with your Hydra setup or database. In this case, you may need to: 1. Recreate the client entirely. 2. Check your database connection and ensure there are no data inconsistencies. 3. Verify that your Hydra version matches the documentation you're following. 4. Consider reaching out to the Ory community or support channels with your specific setup details for further assistance. Remember to always handle client credentials securely and avoid exposing them in logs or error messages.

I apologize for the persistent issue you're facing. Given that you've tried all the previous suggestions and are still encountering the "invalid_client" error, let's explore some additional troubleshooting steps: 1. Verify client existence: Double-check that the client actually exists in the database. You can list all clients using the Hydra CLI:

docker-compose -f quickstart.yml exec hydra \
       hydra list clients \
       --endpoint <http://127.0.0.1:4445>

Ensure your client ID is in this list. 2. Check client secret: The client secret might have been changed or is incorrect. Try updating the client secret:

docker-compose -f quickstart.yml exec hydra \
       hydra update client <your_client_id> \
       --endpoint <http://127.0.0.1:4445> \
       --client-secret <new_secret>

Then use this new secret in your authentication attempt. 3. Verify grant types: Ensure that the client is configured with the correct grant types:

docker-compose -f quickstart.yml exec hydra \
       hydra update client <your_client_id> \
       --endpoint <http://127.0.0.1:4445> \
       --grant-type client_credentials

4. Check for BCrypt secret length limitation: Ory Hydra uses BCrypt for hashing secrets, which has a 72 character limit. If your client secret is longer than 72 characters, it might cause authentication issues. Try using a shorter client secret [Docs > Troubleshooting > 72 character limit for BCrypt hashed secrets](https://www.ory.sh/docs/troubleshooting/bcrypt-secret-length). 5. Inspect the token request: Use a tool like Wireshark or a proxy server to inspect the exact request being sent to Hydra. This can help identify any issues with the request format or headers. 6. Test with a new client: Create a completely new client and try authenticating with it:

docker-compose -f quickstart.yml exec hydra \
       hydra create client \
       --endpoint <http://127.0.0.1:4445> \
       --grant-type client_credentials \
       --response-type token \
       --scope create_identities

Use the new client ID and secret to test authentication. 7. Check Hydra version compatibility: Ensure that your Hydra version is compatible with the client configuration you're using. Some settings or behaviors might have changed between versions. 8. Database integrity: If possible, try resetting your Hydra database and recreating your clients. There might be some data corruption or inconsistency in the current database. 9. Network issues: Verify that there are no network issues, firewalls, or proxies interfering with the communication between your application and Hydra. 10. OAuth2 debug mode: If available in your version of Hydra, try enabling OAuth2 debug mode to get more detailed error messages. Check the Hydra documentation for your specific version on how to enable this.

New message text here