To prevent CORS (Cross-Origin Resource Sharing) issues when using Ory Kratos in a local development environment, you can use Ory Tunnel. Here's how you can address this: 1. Use Ory Tunnel: For local development, it's recommended to use [Ory Tunnel](https://www.ory.sh/docs/kratos/bring-your-own-ui/custom-ui-basic-integration#debug). This tool helps solve CORS errors by proxying requests to your Ory Network project. 2. Add your domain: In production, you should [add your domain to the Ory Project](https://www.ory.sh/docs/kratos/bring-your-own-ui/custom-ui-basic-integration#debug). This allows all requests from your frontend to be made to Ory under the same domain, effectively preventing CORS issues. 3. Avoid using

localhost

or `127.0.0.1`: Ory Network doesn't allow setting CORS origins to

localhost

or

127.0.0.1

. Instead, use Ory Tunnel for local development [as recommended in the CORS guide](https://www.ory.sh/docs/guides/cors). 4. Run with

--dev

flag: If you're running Ory Kratos directly (not recommended for production), you can use the

--dev

flag. This disables

SameSite=Lax

and allows cookies to work over HTTP. For example:

kratos serve --dev

. However, this is [not recommended for production use](https://www.ory.sh/docs/kratos/debug/csrf#running-over-http-without---dev-mode). Remember, Ory has a "deny by default" policy for CORS, so it's crucial to properly configure your development environment to avoid these issues.

This error is a common CORS (Cross-Origin Resource Sharing) issue when developing locally with Ory Kratos. Let's address this problem step by step: 1. The error occurs because you're trying to access

<http://127.0.0.1:4433>

from a different origin, and the CORS header is missing. 2. As mentioned in the [CORS documentation](https://www.ory.sh/docs/guides/cors), Ory Network doesn't allow setting CORS origins to

localhost

or

127.0.0.1

. This is why you're encountering this error. 3. To solve this issue, the recommended approach is to use [Ory Tunnel](https://www.ory.sh/docs/kratos/bring-your-own-ui/custom-ui-basic-integration#debug). Ory Tunnel creates a connection between your local environment and Ory Network, allowing you to bypass CORS issues during development. Here's how you can set up Ory Tunnel: 1. First, make sure you have the Ory CLI installed. 2. Then, run the following command to start Ory Tunnel:

npx @ory/cli tunnel --dev <http://localhost:3000>

Replace

<http://localhost:3000>

with the URL where your frontend application is running. 3. Ory Tunnel will mirror the Ory APIs on

<http://localhost:4000>

. You should use this URL as the

baseUrl

for the

@ory/client

SDK in your application [as explained in the documentation](https://www.ory.sh/docs/getting-started/integrate-auth/react#run-ory-apis-on-localhost). 4. Make sure all your requests are sent to

localhost

and not

127.0.0.1

. As noted in the [limitations section](https://www.ory.sh/docs/getting-started/local-development#limitations), cookies set on

localhost

will not be sent in requests to

127.0.0.1

and vice versa. By following these steps, you should be able to resolve the CORS error and continue with your local development. Remember, Ory Tunnel is for development purposes only and should not be used in production environments.

I understand you've set up Ory Kratos using Docker Compose. That's a great way to get started with Kratos in a local development environment. Let me provide you with some information about setting up Ory Kratos using Docker Compose. To set up Ory Kratos using Docker Compose, you typically follow these steps: 1. Clone the Ory Kratos repository:

git clone <https://github.com/ory/kratos.git>    cd kratos    git checkout master

2. Run Docker Compose:

docker-compose -f quickstart.yml -f quickstart-standalone.yml up --build --force-recreate

If you're using SELinux, you'd use:

docker-compose -f quickstart.yml -f quickstart-selinux.yml -f quickstart-standalone.yml up --build --force-recreate

This setup is described in the [Ory Kratos Quickstart guide](https://www.ory.sh/docs/kratos/quickstart#clone-ory-kratos-and-run-it-in-docker). Once the system is up and running, you should see log messages indicating that Kratos has started its admin and public HTTP servers:

kratos_1 | time="2020-01-20T14:52:13Z" level=info msg="Starting the admin httpd on: 0.0.0.0:4434" kratos_1 | time="2020-01-20T14:52:13Z" level=info msg="Starting the public httpd on: 0.0.0.0:4433"

Remember, when working with this setup: 1. Make sure ports 4433 and 4434 are free on your system. 2. Always use

127.0.0.1

as the hostname instead of

localhost

to avoid issues with cookie settings. If you're planning to integrate this with a frontend application, you might need to consider CORS settings or use Ory Tunnel for local development to avoid CORS issues. Is there anything specific about your Docker Compose setup for Ory Kratos that you'd like to know more about?

To set up Ory Tunnel to connect to Ory Kratos running in Docker, you can follow these steps: 1. First, make sure you have Ory Kratos running in Docker. Based on the [Ory Kratos Quickstart guide](https://www.ory.sh/docs/kratos/quickstart#clone-ory-kratos-and-run-it-in-docker), you should have Kratos running with the following command:

docker-compose -f quickstart.yml -f quickstart-standalone.yml up --build --force-recreate

2. Once Kratos is running, you need to set the

ORY_SDK_URL

environment variable to point to your local Kratos instance. Open a new terminal window and run:

export ORY_SDK_URL=<http://localhost:4433>

This is mentioned in the [Ory documentation for running Kratos locally](https://www.ory.sh/docs/getting-started/integrate-auth/expressjs#run-your-expressjs-app). 3. Now, you can start the Ory Tunnel. Run the following command:

ory tunnel --port 4000 <http://localhost:3000>

This command is based on the [Ory documentation for running the tunnel](https://www.ory.sh/docs/getting-started/integrate-auth/expressjs#run-your-expressjs-app). Replace

<http://localhost:3000>

with the URL where your frontend application is running. 4. The Ory Tunnel will now proxy requests to your local Kratos instance, making it accessible at

<http://localhost:4000>

. 5. In your frontend application, make sure to use

<http://localhost:4000>

as the base URL for Ory SDK requests. Remember, when you run the Ory Tunnel for the first time, it will ask you to log into your Ory Console account. By following these steps, you should be able to connect Ory Tunnel to your Docker-based Ory Kratos instance, effectively solving CORS issues during local development.