feat: add scalar integration (additional alternative to Swagger UI/Redoc)

[marclave]

👋 hey FastAPI, long time fan of everyone's work here and have been eagerly wanting to integrate Scalar's open-source & MIT licensed OpenAPI/Swagger documentation tool to FastAPI.

preview of Scalar integrated with a custom FastAPI theme (not sure on where the best place to add a bit of css is for a custom theme ✨ )

You can play around with what Scalar is like here based on the PetStore https://fastapi.apidocumentation.com

This is also my first time contribution to FastAPI so I am excited for feedback and ready for any requested changes!

[tiangolo]

📝 Docs preview for commit fe9d070 at: https://3908a882.fastapitiangolo.pages.dev

[tiangolo]

📝 Docs preview for commit 3a31862 at: https://e2b8a06b.fastapitiangolo.pages.dev

[tiangolo]

📝 Docs preview for commit 95803ef at: https://52620119.fastapitiangolo.pages.dev

[tiangolo]

📝 Docs preview for commit 36fc23f at: https://db2a9cdc.fastapitiangolo.pages.dev

[nkamali]

@marclave Need scalar_url=None here as well, probably? https://github.com/tiangolo/fastapi/pull/10674/files#diff-2acad16c8816cd891697cf09bc6158a64aeab4091ad4cb7a3e5cce88bb9a1a78R422

[nkamali]

@marclave Do you not need a conditional block similar to this one that exists for redoc, for scalar?

https://github.com/tiangolo/fastapi/pull/10674/files#diff-2acad16c8816cd891697cf09bc6158a64aeab4091ad4cb7a3e5cce88bb9a1a78R1118-R1127

[marclave]

@marclave Do you not need a conditional block similar to this one that exists for redoc, for scalar?

https://github.com/tiangolo/fastapi/pull/10674/files#diff-2acad16c8816cd891697cf09bc6158a64aeab4091ad4cb7a3e5cce88bb9a1a78R1118-R1127

we do have one right below where you referenced :)

https://github.com/tiangolo/fastapi/pull/10674/files#diff-2acad16c8816cd891697cf09bc6158a64aeab4091ad4cb7a3e5cce88bb9a1a78R1129

[marclave]

@marclave Need scalar_url=None here as well, probably? https://github.com/tiangolo/fastapi/pull/10674/files#diff-2acad16c8816cd891697cf09bc6158a64aeab4091ad4cb7a3e5cce88bb9a1a78R422

ah good catch! I wrote the tests for it but didnt update the docs there.

Just pushed up a commit to fix this :)

[tiangolo]

📝 Docs preview for commit 8a79d14 at: https://8318b0bb.fastapitiangolo.pages.dev

[tiangolo]

📝 Docs preview for commit 08f43fd at: https://49a76bae.fastapitiangolo.pages.dev

[tiangolo]

📝 Docs preview for commit 743a4c5 at: https://2f17ff93.fastapitiangolo.pages.dev

[hasansezertasan]

LGTM, great job.

[hasansezertasan]

@marclave I'm quite excited about this. Hope you'll soon fix failed checks.

[marclave]

@marclave I'm quite excited about this. Hope you'll soon fix failed checks.

@hasansezertasan im glad you're excited! We are too ✨

I'll fix up these build issues this weekend :)

[marclave]

@tiangolo did something change with building of the docs? I might need to make a fresh PR but im not sure what's happening based on the logs. any guidance would be great ✨

[hasansezertasan]

Hello @marclave, is there any update on this?

[marclave]

Hello @marclave, is there any update on this?

waiting on a review from @tiangolo :) also im not sure why build docs is failing tho, any insights there would be great ✨ I could do a fresh rebase and maybe that will fix it

[hasansezertasan]

waiting on a review from @tiangolo :) also im not sure why build docs is failing tho

I'm not sure either. 😕

About the review, I recommend you to read this #10437 (comment) from the author, especially this sentence: "I'm also considering trimming a bit these things and simplify the way that automatic OpenAPI UIs are provided, probably removing the default ReDoc and making it opt-in. But that will come later." 😞

I interpreted that sentence as "No more alternative automatic OpenAPI UI's will be included.". What do you think about it @marclave?

I also created a package called openapipages and included Scalar to it (based on this PR 🙏). I would not say no to a 🌟. Let me know what you think about it 🤓

[marclave]

waiting on a review from @tiangolo :) also im not sure why build docs is failing tho

I'm not sure either. 😕

About the review, I recommend you to read this #10437 (comment) from the author, especially this sentence: "I'm also considering trimming a bit these things and simplify the way that automatic OpenAPI UIs are provided, probably removing the default ReDoc and making it opt-in. But that will come later." 😞

I interpreted that sentence as "No more alternative automatic OpenAPI UI's will be included.". What do you think about it @marclave?

I also created a package called openapipages and included Scalar to it (based on this PR 🙏). I would not say no to a 🌟. Let me know what you think about it 🤓

Wow thanks for adding scalar @hasansezertasan ! I gave it a star 💫

Would be cool to add your package to the documentation of FastAPI then ✨

[hasansezertasan]

Wow thanks for adding scalar @hasansezertasan ! I gave it a star 💫

Thank you, I'm grateful 🙏. Of course, I'm gonna add Scalar API, it's a great tool (it's my fav so far)!

Would be cool to add your package to the documentation of FastAPI then ✨

Well, where (which page) do you recommend adding it to? As far as I remember, FastAPI documentation doesn't have a page for third-party-extensions like Starlette (Third Party Packages - Starlette)

[marclave]

Wow thanks for adding scalar @hasansezertasan ! I gave it a star 💫

Thank you, I'm grateful 🙏. Of course, I'm gonna add Scalar API, it's a great tool (it's my fav so far)!

Would be cool to add your package to the documentation of FastAPI then ✨

Well, where (which page) do you recommend adding it to? As far as I remember, FastAPI documentation doesn't have a page for third-party-extensions like Starlette (Third Party Packages - Starlette)

I'm not entirely sure where it should go to be honest. But maybe in the root README? Or maybe we should have a page for third party extensions ✨

[hasansezertasan]

I'm not entirely sure where it should go to be honest. But maybe in the root README? Or maybe we should have a page for third party extensions ✨

I'm not sure if the author would promote openapipages in the README but I believe there can be a page called "More Alternative Interfaces" next to "Configure Swagger UI" page that demonstrates Scalar integration using openapipages package.

I also been longing for a third-party-extensions page.

WDYT about it @tiangolo? I can work on "More Alternative Interfaces" page if you like the idea.

Edit: I started a discussion at #11158, check it out 🥇.

[marclave]

we got an official integration! scalar/scalar#1534

pip install scalar-fastapi

from fastapi import FastAPI
from scalar_fastapi import get_scalar_api_reference

app = FastAPI()

@app.get("/")
def read_root():
    return {"Hello": "World"}

@app.get("/scalar", include_in_schema=False)
async def scalar_html():
    return get_scalar_api_reference(
        openapi_url=app.openapi_url,
    )