Based on the error message you're receiving, it appears that there's an issue with client authentication when calling the OAuth2 token endpoint. This error typically occurs when the client credentials (client ID and client secret) are incorrect or not properly provided. Let's go through some possible reasons and solutions: 1. Client Authentication Method: Make sure you're using the correct authentication method for your client. Ory Hydra supports multiple methods, including

client_secret_basic

(default) and

client_secret_post

. [Hydra API Reference](https://www.ory.sh/docs/hydra/reference/api) mentions that the token endpoint supports both basic auth and form data. 2. Client Credentials: Double-check that you're using the correct client ID and client secret. The error message suggests that the passwords (client secret) do not match. 3. Token Endpoint Auth Method: Verify that your OAuth2 client is configured with the correct

token_endpoint_auth_method

. You can check this using the Ory CLI:

ory get oauth2-client {client.id}

Look for the

token_endpoint_auth_method

field in the output. [Hydra Debug Guide](https://www.ory.sh/docs/hydra/debug/token-endpoint-auth-method) provides more information on this. 4. Request Format: Ensure that your request to the token endpoint is properly formatted. Here's an example of how it should look:

POST /oauth2/token    Content-Type: application/x-www-form-urlencoded     grant_type=authorization_code&    code={code}&    redirect_uri={redirect_uri}&    client_id={client_id}&    client_secret={client_secret}

[OAuth2 Authorization Code Flow Guide](https://www.ory.sh/docs/oauth2-oidc/authorization-code-flow#step-4-exchange-code-for-token) provides details on the required parameters. 5. Redirect URI: Make sure the

redirect_uri

you're using in the token request matches exactly with the one you registered for your client. If you've verified all of the above and are still encountering issues, you may want to enable debug logging in Ory Hydra to get more detailed error information. Additionally, double-check that you're using the correct endpoint URL for your Ory Hydra instance. If the problem persists, you might want to recreate your OAuth2 client with the correct settings using the Ory CLI:

ory create oauth2-client --project $project_id \   --name "Your Client Name" \   --grant-type authorization_code,refresh_token \   --response-type code \   --redirect-uri <http://your-redirect-uri>

[Ory CLI Documentation](https://www.ory.sh/docs/hydra/cli/hydra-create-oauth2-client) provides more details on creating OAuth2 clients. Remember to update your application with the new client credentials after recreating the client.

I understand that you're self-hosting Ory Hydra locally. This information helps clarify your setup. For a local self-hosted Ory Hydra instance, there are a few specific things to consider: 1. Endpoint Configuration: Ensure that you're using the correct local endpoints. For a typical local setup, the admin API endpoint is usually

<http://127.0.0.1:4445>

, and the public API endpoint is

<http://127.0.0.1:4444>

[Hydra Self-Hosted Guide](https://www.ory.sh/docs/hydra/self-hosted/configure-deploy). 2. Client Creation: When creating an OAuth2 client for a local setup, you need to use the Ory Hydra CLI with the local admin endpoint. Here's an example command:

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

[Ory Hydra Self-Hosted Guide](https://www.ory.sh/run-oauth2-server-open-source-api-security/#performing-the-oauth2-client-credentials-flow) provides more details on this. 3. Verifying Client Configuration: You can check your client's configuration using a similar command:

docker run --rm -it --network hydraguide oryd/hydra:v2.0.1 \      get oauth2-client {client.id} \        --endpoint <http://ory-hydra-example--hydra:4445>

This will show you the client's settings, including the

token_endpoint_auth_method

[Hydra Debug Guide](https://www.ory.sh/docs/hydra/debug/token-endpoint-auth-method). 4. Token Introspection: For debugging purposes, you can introspect the token using:

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

[Ory Hydra Self-Hosted Guide](https://www.ory.sh/run-oauth2-server-open-source-api-security/#performing-the-oauth2-client-credentials-flow) shows how to use this command. 5. Troubleshooting: If you're still encountering issues, you might want to check the Hydra logs for more detailed error messages. In a local setup, you can usually access these directly from your Docker logs. Remember to adjust the network settings and container names in these commands to match your specific local setup. If you continue to face issues, you might want to review the full [Ory Hydra Self-Hosted Guide](https://www.ory.sh/docs/hydra/self-hosted/configure-deploy) to ensure all components are correctly configured for local use.

Thank you for providing the details of how you created the client. Let's analyze your command and see if there are any potential issues or improvements that can be made. The command you've used looks generally correct, but there are a few points to consider: 1. Endpoint: You're using the correct admin endpoint (`http://localhost:4445/`), which is good [Hydra Self-Hosted Guide](https://www.ory.sh/docs/hydra/self-hosted/configure-deploy#perform-oauth-20-flow). 2. Grant Types and Response Types: The

authorization_code

and

refresh_token

grant types, along with the

code

response type, are correctly specified for the Authorization Code flow [Hydra CLI Documentation](https://www.ory.sh/docs/hydra/cli/hydra-create-client). 3. Redirect URI: Your redirect URI (`http://localhost:5173/account/callback`) is specified, which is important. 4. Scopes: You've included

openid

and

offline_access

scopes, which are correct for obtaining an ID token and refresh token [Hydra 5 Minute Tutorial](https://www.ory.sh/docs/hydra/5min-tutorial). 5. Skip Consent: You've set

--skip-consent=true

and

--skip-logout-consent=true

. While this can be useful for development, be cautious about using these in production as they bypass important security steps. One thing that's not explicitly set in your command is the

token_endpoint_auth_method

. By default, it's set to

client_secret_basic

. If you're having issues with client authentication, you might want to specify this explicitly:

bash docker compose -f docker-compose.dev.yaml exec hydra \ hydra create client \   --endpoint <http://localhost:4445/> \   --redirect-uri <http://localhost:5173/account/callback> \   --grant-type authorization_code,refresh_token \   --response-type code \   --skip-consent=true \   --skip-logout-consent=true \   --scope openid,offline_access \   --token-endpoint-auth-method client_secret_post

The

client_secret_post

method is often used when you're sending the client credentials in the POST body of your token request [Hydra Debug Guide](https://www.ory.sh/docs/hydra/debug/token-endpoint-auth-method). After creating the client, you should receive a client ID and client secret. Make sure you're using these correctly in your token request. If you're still encountering the "invalid_client" error, double-check that you're including the correct client ID and secret in your request to the

/oauth2/token

endpoint. If the issue persists, you might want to enable debug logging in your Hydra instance to get more detailed error messages. This can often provide more insight into why the client authentication is failing.