Backend: Create a new /explain endpoint to generate code explanations

[dineshsutihar]

Is your feature request related to a problem?

The extension is great at translating code, but users (especially learners) might also want to understand what the code does.

Describe the solution you'd like

Create a new API endpoint, for example, /explain. This endpoint will receive a code snippet. The worker will then call the Gemini API with a different, specialized prompt, asking it to provide a concise, natural-language explanation of the code's function, its inputs, and its outputs.

Additional context

This requires significant prompt engineering to get a consistently good explanation from the AI. The frontend would also need to be updated later to add an "Explain" button to the UI, but the first step is creating this backend capability.

[hemanth5055]

Hi @dineshsutihar ! I'd love to work on this feature. Creating an /explain API endpoint and integrating prompt engineering for clear code explanations sounds exciting. Could you please assign this issue to me?

[dineshsutihar]

Hi @hemanth5055 ,
I've assigned the issue to you.

[hemanth5055]

Hi @dineshsutihar,

Here is the working output for the /explain endpoint:

Important:
I've added support for both /translate and /explain endpoints.
Previously, the frontend was sending requests directly to the root URL. Now, we need to update the frontend to use the appropriate paths (/translate for code translation and /explain for code explanation).

Let me know if you'd like any further improvements or adjustments.

[dineshsutihar]

Thanks for implementing support for both /translate and /explain routes. this is exactly the direction we want to move in.

For now, to avoid breaking the existing production usage (which still relies on POST /), I'd like to request a small change:

Could you please update the PR to include:

• POST /v1/translate (new versioned route)
• POST /v1/explain (new versioned route)
• Preserve the current behavior of POST / (for backward compatibility)

This way, we can safely roll out /v1/* endpoints while the extension continues using /, and we’ll migrate once we’ve verified everything.

Once you've pushed the changes, I'll deploy it to a staging environment and test everything from our side.

Let me know if you need help adjusting the route handling logic or anything else before opening the PR.