# JustBuildApps

> JustBuildApps is a discovery site for apps built with AI tools ("vibecoded" apps): 886 apps, each with a description and, for most, a live demo URL. When a user needs software for a task, AI agents can search it by task, find alternatives, check an app's health and hand the user a working link instead of building from scratch. No API key needed to read.

Human-readable version: https://justbuildapps.com/for-agents. Short index: https://justbuildapps.com/llms.txt.

## What you can do

- Find an app for a task: semantic search over descriptions.
- Find alternatives to an app the user names or already tried.
- Hand the user a live demo: verified results have a demo_url they can open now.
- Check health before recommending: healthy, degraded or down.
- Report broken apps and submit new ones, including apps you just built.

Catalog right now: 886 published apps, 868 with a live demo URL.

## Recommended flow

1. Search by the user's task: POST /api/v1/agent/search (MCP: search_apps).
2. Take the top 1 to 3 by relevance_score and read the descriptions; skip weak matches rather than forcing one.
3. Check each pick: GET /api/v1/agent/verify/{app_id} (MCP: verify_app). Prefer healthy.
4. Need options? GET /api/v1/apps/{app_id}/similar (MCP: get_similar_apps).
5. Give the user the demo_url to use it and the JustBuildApps page to read about it.
6. If a demo is broken, report it: POST /api/v1/agent/feedback with feedback_type tool_broken.

## MCP server

Hosted remote (Streamable HTTP, no install): https://api.justbuildapps.com/mcp

```json
{
  "mcpServers": {
    "justbuildapps": {
      "type": "streamable-http",
      "url": "https://api.justbuildapps.com/mcp"
    }
  }
}
```

Local (needs uv):

```json
{
  "mcpServers": {
    "justbuildapps": { "command": "uvx", "args": ["justbuildapps-mcp"] }
  }
}
```

Registry name io.github.sksareen/justbuildapps, PyPI package justbuildapps-mcp, manifest https://justbuildapps.com/mcp.json, docs https://justbuildapps.com/mcp.

### Tools

Discovery (no auth):

- search_apps: Semantic search by task: ranked tools with relevance, demo URL, pricing, usage guidance.
- browse_apps: Filter and page the catalog (pricing, audience, sort).
- get_app: Full metadata for one app.
- get_similar_apps: Alternatives to an app.
- get_trending: Trending, top-rated and newest in one call.
- verify_app: Health check before recommending: healthy/degraded/down plus reliability score.
- list_capabilities: Every category/capability in the catalog.
- get_stats: Catalog statistics.

Creators and feed (no auth):

- get_creator: A creator's profile with creations and update history.
- search_creators: Typeahead over creator handles and names.
- get_feed: Cross-creator feed of launches, iterations and notes.
- get_creation: One creation (project) with its update history.

Writes (no auth):

- submit_app: Submit an app; metadata and screenshot are extracted automatically.
- submit_feedback: Report a broken tool, rate usefulness, suggest improvements.

Writes (need a jba_ token as JBA_API_TOKEN):

- create_creation: Create a project under your creator profile.
- post_update: Post a launch, iteration or note to a creation you own.

Resources: jba://apps/{app_id}, jba://creators/{handle}, jba://feed. Prompts: recommend, alternatives.

## REST API

Base URL: https://api.justbuildapps.com/api/v1 (also https://justbuildapps.com/api/v1). JSON in, JSON out. Examples are real responses, trimmed.

### Agent API

Built for agents: structured tool metadata, ranked by relevance to a task.

#### POST /api/v1/agent/search

Semantic search by task. Best first call when a user needs software. Falls back to keyword match if embeddings are unavailable.

Parameters: Body: query (required), context (optional extra detail), constraints (optional: {"cost": "free"|"freemium"|"paid"|"open_source", "no_auth": true, "audience": "agent"|"human"|"both"}), limit (default 10). Query string: quality=verified (default, only apps with a demo URL) or all.

```bash
curl -X POST https://api.justbuildapps.com/api/v1/agent/search \
  -H "Content-Type: application/json" \
  -d '{"query": "remove background from product photos", "limit": 2}'
```

```json
{
  "query": "remove background from product photos",
  "tools": [
    {
      "tool": {
        "app_id": 649,
        "name": "Remove.bg",
        "description": "Automatic background removal tool. Upload any image and get the background removed in seconds using AI. ...",
        "demo_url": "https://www.remove.bg",
        "target_audience": null,
        "capabilities": ["image_editing", "visual_design", "image_generation"],
        "use_cases": ["When user needs automatic background removal tool", "For remove.bg tasks"],
        "cost_model": "free",
        "requires_auth": false,
        "iframe_compatible": true,
        "confidence_score": 0.85,
        "verification_status": "verified",
        "last_verified": "2026-10-12T00:57:12.613384",
        "quick_start": "Visit https://www.remove.bg to start using this tool",
        "limitations": [],
        "docs_url": null,
        "npm_package": null,
        "pypi_package": null,
        "install_command": null
      },
      "relevance_score": 0.56,
      "match_reason": "Semantic similarity match",
      "how_to_use": "1. Open https://www.remove.bg\n2. Visit https://www.remove.bg to start using this tool"
    }
  ],
  "total_found": 2
}
```

#### GET /api/v1/agent/verify/{app_id}

Health check before you recommend an app. status is healthy, degraded or down. These are catalog checks (has a demo URL, published, updated within 90 days), not a live HTTP probe.

```bash
curl https://api.justbuildapps.com/api/v1/agent/verify/649
```

```json
{
  "app_id": 649,
  "name": "Remove.bg",
  "status": "healthy",
  "checks": {
    "has_demo_url": true,
    "has_description": true,
    "is_published": true,
    "recently_updated": true
  },
  "last_verified": "2026-10-12T21:13:46.898634",
  "reliability_score": 0.95
}
```

#### GET /api/v1/agent/tools/{app_id}

Structured metadata for one app (the same `tool` object search returns). 404 if unknown.

```bash
curl https://api.justbuildapps.com/api/v1/agent/tools/649
```

#### GET /api/v1/agent/tools

List apps as tool metadata, plus the categories and capabilities present in the result.

Parameters: category (tag), capability, cost (free|freemium|paid|open_source), audience (agent|human|both), quality (verified|all, default verified), limit (default 100, max 1000).

```bash
curl "https://api.justbuildapps.com/api/v1/agent/tools?cost=free&limit=20"
```

```json
{
  "tools": [ { "app_id": 500, "name": "Manyfold 3D", "demo_url": "https://manyfold.app", "cost_model": "free", ... } ],
  "total": 1,
  "categories": ["3d-models", "3d-printing", "assets", "file-management", "organization"],
  "capabilities": ["3d-models", "3d-printing", "prototyping", "ui_design", ...]
}
```

#### GET /api/v1/agent/capabilities

Every tag/capability in the catalog. Use it to pick a category filter.

```bash
curl https://api.justbuildapps.com/api/v1/agent/capabilities
```

```json
{ "capabilities": ["2fa", "3d-models", "ai", "analytics", ...], "total": 1234 }
```

#### GET /api/v1/agent/stats

Catalog size and quality counts.

```bash
curl https://api.justbuildapps.com/api/v1/agent/stats
```

```json
{
  "total_tools": 832,
  "tools_with_demo": 814,
  "iframe_compatible": 814,
  "average_rating": 5.0,
  "last_updated": "2026-10-12T21:13:39.718842"
}
```

#### POST /api/v1/agent/feedback

Tell us an app is broken, mislabeled or helpful. Reports are stored and reviewed; they feed what we recommend.

Parameters: feedback_type (required): tool_helpful | tool_not_helpful | tool_broken | tool_incorrect | wrong_audience | suggestion | other. Optional: app_id, rating (1-5), message, query, agent_name, agent_context, extra_metadata.

```bash
curl -X POST https://api.justbuildapps.com/api/v1/agent/feedback \
  -H "Content-Type: application/json" \
  -d '{"agent_name": "my-agent", "app_id": 649, "feedback_type": "tool_broken", "message": "demo URL returns 502", "query": "remove background"}'
```

```json
{
  "id": 123,
  "message": "Feedback received successfully",
  "thank_you": "Thanks for reporting this! We'll verify and fix the tool listing."
}
```

### Catalog API

The same endpoints the site uses. Good for alternatives, trending and paging through everything.

#### GET /api/v1/apps/{app_id}/similar

Alternatives to an app, by embedding similarity.

Parameters: limit (default 5, max 20).

```bash
curl "https://api.justbuildapps.com/api/v1/apps/649/similar?limit=2"
```

```json
{
  "apps": [
    { "id": 815, "title": "Raphael AI", "description": "...", "demo_url": "https://raphael.app", "similarity": 0.49, ... },
    { "id": 816, "title": "Yeri AI", "description": "...", "demo_url": "https://yeri.ai", "similarity": 0.47, ... }
  ]
}
```

#### GET /api/v1/apps/{app_id}

Full record for one app: title, description, app_type, tags, tech_stack, github_url, github_stars, demo_url, screenshot_url, status.

```bash
curl https://api.justbuildapps.com/api/v1/apps/649
```

#### GET /api/v1/search

Hybrid keyword + fuzzy + semantic search. Returns full app records.

Parameters: q (required), limit (default 10, max 100).

```bash
curl "https://api.justbuildapps.com/api/v1/search?q=pomodoro&limit=5"
```

#### GET /api/v1/browse

Filter, sort and page through the whole catalog.

Parameters: page, per_page (max 100), sort_by (created_at|rating|github_stars|title|view_count), sort_order (asc|desc), app_type, audience (agent|human|both), pricing (free|freemium|paid|open_source), search, has_demo.

```bash
curl "https://api.justbuildapps.com/api/v1/browse?pricing=free&has_demo=true&per_page=24"
```

```json
{ "apps": [ ... ], "total": 833, "page": 1, "per_page": 24, "total_pages": 35 }
```

#### GET /api/v1/trending

Three lists in one call: trending (most viewed), top_rated, new_apps.

Parameters: limit (default 10, max 50).

```bash
curl "https://api.justbuildapps.com/api/v1/trending?limit=5"
```

#### GET /api/v1/home

App cards as the site shows them, each with `href` (its page on justbuildapps.com) and `live` (whether it plays inside JBA).

Parameters: filter (trending|staff|top|recent|oss|builders|claimed), q, ids (comma-separated), skip, limit.

```bash
curl "https://api.justbuildapps.com/api/v1/home?filter=trending&limit=1"
```

```json
{
  "cards": [
    {
      "app_id": 818,
      "title": "Doodle",
      "tagline": "doodle jump meets reinforcement learning — watch a bot learn to play",
      "thumbnail_url": "/api/v1/screenshots/creation/6",
      "accent": "slate",
      "demo_url": "https://savarsareen.com/doodle",
      "href": "/u/savar/doodle",
      "live": true,
      "open_source": false,
      "channel": { "handle": "savar", "name": "Savar", "avatar_url": "/api/v1/media/....png" },
      "views": 19,
      "published_at": "2026-10-05T04:27:30.655417",
      "reason": null
    }
  ],
  "total": 814
}
```

#### GET /api/v1/sitemap/apps

Every public app page path, for bulk crawling. Paged.

Parameters: skip, limit.

```bash
curl "https://api.justbuildapps.com/api/v1/sitemap/apps?skip=0&limit=3"
```

```json
{
  "items": [
    { "app_id": 824, "path": "/u/savar/sudoku-bench", "updated_at": "2026-10-12T00:56:01.162814" }
  ],
  "total": 832
}
```

### Submit

Add an app you built or found.

#### POST /api/v1/ingest

Submit a GitHub repo (analyzed automatically) or a web app (title + description + demo_url). A screenshot is captured in the background. Signed-in users are limited to 5 submissions a day.

```bash
curl -X POST https://api.justbuildapps.com/api/v1/ingest \
  -H "Content-Type: application/json" \
  -d '{"title": "App Name", "description": "What it does", "demo_url": "https://example.com"}'

# or
curl -X POST https://api.justbuildapps.com/api/v1/ingest \
  -H "Content-Type: application/json" \
  -d '{"github_url": "https://github.com/owner/repo"}'
```

Creator profiles, feeds and authenticated writes: https://justbuildapps.com/developers

## App data model

- app_id: Stable numeric id. Use it with /agent/verify, /agent/tools and /apps/{id}/similar.
- title / name: App name.
- tagline / description: One line / full description of what it does.
- demo_url: Where the app actually runs. Send users here to use it.
- href: Its page on JustBuildApps: /u/{handle}/{slug} for a builder's app, /app/{id} for a catalog listing.
- live: true if it plays inside JustBuildApps, false if the site blocks embedding, null if not checked yet.
- open_source / github_url: Whether source is public, and where.
- channel: The builder (handle, name, avatar). handle is null for unclaimed listings.
- cost_model: free | freemium | paid | open_source. Defaults to free when unknown, so check the app's own pricing for money decisions.
- target_audience: agent (APIs, CLIs, MCP servers) | human (UI apps) | both | null if unknown.
- thumbnail_url / screenshot_url: Screenshot path, relative to justbuildapps.com (e.g. /api/v1/screenshots/649).

## Auth and rate limits

- Reads, search, verify, feedback and app submission need no API key.
- Acting as a creator needs a personal jba_ token from https://justbuildapps.com/settings/tokens, sent as "Authorization: Bearer jba_..." (JBA_API_TOKEN for the MCP server).
- No hard rate limit on read endpoints today. Cache results, keep bulk work to about one request per second, and enumerate the catalog via /api/v1/sitemap/apps rather than paging search.
- Signed-in users can submit 5 apps a day. Token writes are limited to 60/hour per creator and return 429 with Retry-After.

## Attribution and linking

- Send users to the app via demo_url; that's where it runs.
- Cite its JustBuildApps page: the card's href on https://justbuildapps.com, or https://justbuildapps.com/app/{app_id}, which works for every app and redirects to the canonical page.
- Credit the builder by name or handle when you have it (channel).
- Don't present a listing as endorsed beyond what verify reports. Pricing in our data can be wrong; check the app's own site before a money decision.

## Crawling

- https://justbuildapps.com/robots.txt: AI crawlers are welcome on app pages, builder profiles and docs.
- https://justbuildapps.com/sitemap.xml: every public app and builder page.
- App pages carry JSON-LD (WebApplication) and Open Graph metadata.

## Example app pages

- [Launched Badges](https://justbuildapps.com/app/1005): Launched Badges offers universal React components to showcase product launches across platforms like Lovable, Reddit, and Hacker News, built with Lovable.
- [Play QuakeWorld Multiplayer Online - q1.pieter.com (Non-commercial and unofficial)](https://justbuildapps.com/app/866): Play QuakeWorld in your browser at q1.pieter.com — low-latency multiplayer deathmatch with client-side prediction, no install.
- [Graphical](https://justbuildapps.com/app/962): A tool to create visual themes, customize components, and build interfaces with your coding agent.
- [How Much Is My Side Project Worth?](https://justbuildapps.com/app/900): For many it's unclear what their side projects are worth. Many want to sell, or have people interested in buying but have no idea how to get to a proper price. This calculator helps you figure out a…
- [Wine-Assembly — Run Windows 98 apps and games in your browser](https://justbuildapps.com/app/955): Play Space Cadet Pinball, SkiFree, Solitaire, Minesweeper, Winamp and dozens of real Windows 98 programs in your browser. Wine-Assembly runs the original .exe files on an x86 emulator written in…

## Contact

Email automatejobhunt@gmail.com or https://x.com/justbuildapps. Agents can file reports with POST /api/v1/agent/feedback.