Tooling: local playground UI for exploring an index

[HarshaNalluru]

Description

A small local web app to load an index, run queries, and inspect results and scores.

Use case

Developers want to eyeball search quality and tune parameters without writing code.

Proposed solution

Ship a local playground, served by the CLI or the WASM build, to query an index and view ranked results, scores, and filters. Moss JS API: https://docs.moss.dev/docs/reference/js/api Contributing guide: https://github.com/usemoss/moss/blob/main/CONTRIBUTING.md

Alternatives considered

No response

[msranjana]

Hi @HarshaNalluru, I was thinking of adding a moss playground command to the Python CLI (packages/moss-cli/).

The idea is for it to start a small local HTTP server that:

• Serves a simple HTML/JS playground UI.
• Exposes endpoints to list and load local Moss index files (GET /api/indexes and GET /api/index?name=...).
• Uses @moss-dev/moss-web (WASM) in the browser so queries run locally, which keeps them fast and doesn't require cloud credentials.
• Reuses the existing playground experience from apps/next-js/, including ranked results, scores, latency, Top-K, and Alpha controls.

The CLI usage would look something like:

moss playground --index-dir ./indexes

This would open the playground in the browser, let you load a local index, and query it interactively.

Files to touch (all in packages/moss-cli/)

• New: src/moss_cli/commands/playground.py – CLI command + local HTTP server
• New:src/moss_cli/playground/index.html – Query UI
• Edit: src/moss_cli/main.py – Register the playground command

If this approach sounds good, I would be happy to implement it. Open to any feedback or suggestions before I start :)

[Sravan1011]

@msranjana go ahead with this implementation, this approach sounds perfect.

[msranjana]

@Sravan1011 will ship it soon and make a pr

[Sravan1011]

Some one did ig

[msranjana]

Added documentation for the local playground UI in the getting started guide.

hi @Sravan1011 , I noticed that the previous PR linked to this issue only adds documentation about the local playground UI and doesn't implement the actual playground functionality described in the issue.

[Sravan1011]

@msranjana ya sorry go ahead making a pr,