# three.ws MCP Tool Catalog Discovery

> three.ws MCP Tool Catalog Discovery is a paid API for AI agents from three.ws, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-11).

Discovers, syncs, and lists the live catalog of MCP tools available on the three.ws 3D agent platform, diffing against the durable registry and persisting changes.

## Facts

- Endpoint: POST https://three.ws/api/x402/mcp-tool-catalog?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/three-ws-mcp-tool-catalog-discovery-4dc58cd5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_X_6-88rfHEGnNzWoNXHnn

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability three-ws-mcp-tool-catalog-discovery-4dc58cd5 -d '<json body>'
```

Example prompt: Check the three.ws MCP tool catalog in discover mode so we get a full diff of what's new, changed, or removed compared to the saved registry.

## When to prefer this

Use this endpoint when you need to keep an agent's local tool registry in sync with the live three.ws MCP tool catalog, detect new or repriced tools automatically, or get a point-in-time snapshot of what 3D agent capabilities are available. Prefer 'list' mode for read-only inspection without side effects; use 'discover' or 'sync' when you want persistent state updates. Ideal for agents that orchestrate or resell three.ws capabilities.

## Known failure modes

- Invalid mode value returns validation error
- Payment of 0.001 USDC not received causes 402 response
- Registry persistence failure may cause sync to report success but not save state
- Catalog service temporarily unavailable returns 5xx error
- Stale catalog data if upstream three.ws tool registry has not refreshed

## How this service works

Make a 3D AI agent from a selfie in 60 seconds. Drop one HTML tag to embed it on any website. Agents think on IBM watsonx.ai (Granite); optionally charge per chat with built-in micropayments.

## Output

Returns a JSON object with ok status, timestamp, mode used, arrays of new/changed/removed tools (with names, prices, and descriptions), plus summary counts of free, priced, and total tools in the catalog.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "mode": {
   "enum": [
    "discover",
    "sync",
    "list"
   ],
   "type": "string",
   "default": "discover",
   "description": "\"discover\" / \"sync\" (default \"discover\") diffs the live catalog against the durable registry and persists the new state. \"list\" returns the live catalog snapshot only (no diff, no persistence). \"sync\" is an alias for \"discover\"."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "ts": "2026-06-27T10:00:00.000Z",
  "mode": "discover",
  "new_tools": [
   {
    "name": "segment_model",
    "priced": true,
    "price_usdc": 0.02,
    "description": "Split a mesh into named parts",
    "input_fields": 2
   }
  ],
  "free_tools": 13,
  "total_tools": 24,
  "priced_tools": 11,
  "changed_tools": [
   {
    "name": "render_avatar",
    "change": "price",
    "price_usdc": 0.005,
    "prev_price_usdc": 0.003
   }
  ],
  "removed_tools": []
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/three-ws-mcp-tool-catalog-discovery-4dc58cd5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from three.ws](https://www.zero.xyz/host/three.ws/llms.txt)