feat(deploy): add custom-server-url option

[hakkiai]

Description

Added a new --custom-server-url option to the deploy command for both Fly.io and Railway providers.

This flag allows users to explicitly set the server URL that the client app should connect to.
It’s useful when deploying to a custom domain or when the inferred URL is incorrect (e.g., reverse proxy, custom routing).

The precedence for determining the server URL is now:

1. --custom-server-url (CLI)
2. REACT_APP_API_URL (env var)
3. Default inferred URL (Fly.io or Railway)

This improves flexibility when deploying and makes custom-domain setups easier without relying solely on env variables.

Type of change

• 🚀 New/improved feature

Checklist

• I tested my change in a Wasp app to verify that it works as intended.

🧪 Tests and apps:

• I added unit tests for my change.
• I added/updated e2e tests if needed.
• I updated starter templates as needed.
• I updated example apps as needed.
• I updated tutorial docs if affected.

📜 Documentation:

• I added/updated the documentation in web/docs/ if needed.

🆕 Changelog:

• I updated waspc/ChangeLog.md with a user-friendly description of the change.

• I bumped the version in waspc/waspc.cabal if required.

• Fixes Specify custom server URL via an explict option #3431

[infomiho]

@hakkiai thank you for the contribution! Can you ask you to use the official PR template and fill it out: https://raw.githubusercontent.com/wasp-lang/wasp/refs/heads/main/.github/pull_request_template.md

Someone from the team will review this soon :)

[hakkiai]

Thanks @infomiho

I’ve updated the PR to use the official template and filled everything out.

[infomiho]

@hakkiai great!

Can I ask you to run ./run prettier:format from the waspc dir? The formatting CI is failing, let's take care of that: https://github.com/wasp-lang/wasp/actions/runs/19674523584/job/56351941849?pr=3437

Also, please add an entry to the ChangeLog.md (as per the PR template checklist) under the unreleased version?

[hakkiai]

Hi @infomiho,

Thanks for pointing it out. I've now run ./run prettier:format from the waspc directory and updated the formatting.

Also added the missing entry to ChangeLog.md

Just pushed the changes.

[infomiho]

Hey @hakkiai look at your latest commit: e991e5e, there were no formatting changes and the CI is still failing: https://github.com/wasp-lang/wasp/actions/runs/19700569960/job/56442249432?pr=3437

Please make sure you ran the ./run prettier:format successfully.

I also noticed that you committed some of local helper waspc/packages/deploy/flyctl.cmd which you can remove with git rm so it's no longer tracked.

[hakkiai]

Thanks for the review again @infomiho

I've removed the flyctl.cmd file.

I ran the Prettier formatter once more successfully.

I had already run ./run prettier:format earlier, I think the CI was failing because it was trying to format that flyctl.cmd file. Now that it’s removed, that shouldn’t be an issue anymore.

I also resolved the merge conflict in ChangeLog.md and pushed the updates.

[infomiho]

@hakkiai The CI is still failing on formatting, check it here and you'll see which files are not formatted: https://github.com/wasp-lang/wasp/actions/runs/19743464571/job/56632265983?pr=3437 once you run the ./run prettier:format successfully you'll see that those files changed.

Also, the ChangeLog.md looks like you added two things. Make sure to update your work and merge the main branch back into your branch.

[hakkiai]

Sorry for the back & forth changes @infomiho

Actually prettier is running successfully for me, i ran it on the package where I made the updates, and it is reporting no changes, so I am not sure why CI is failing.

This time to be 100% sure, I’ve now run npm run prettier:check on the whole project, and found formatting errors in deploy.ts while everything else stayed unchanged. pushed those changes. I also added the missing changelog entry that got lost during the merge.

Everything should be green now hopefully. Thanks for your patience @infomiho

[infomiho]

@hakkiai Let's resolve the conflicts:

1. Make sure your fork's main is up to date with the main repo (https://github.com/hakkiai/wasp/tree/main)
2. Merge main into your branch and resolve the conflicts.