# Linkrra Pearl Pool Chat Completions

> Linkrra Pearl Pool Chat Completions is a paid API for AI agents from pool.linkrra.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-28).

OpenAI-compatible chat completions paid per request in USDC on Base via x402, requiring no API key or account

## Facts

- Endpoint: POST https://pool.linkrra.com/v1/chat/completions?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-28
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/linkrra-pearl-pool-chat-completions-e27aec76
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5d4yXTIIX4d33F3rtgSck

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 linkrra-pearl-pool-chat-completions-e27aec76 -d '<json body>'
```

Example prompt: Without signing up for anything, send this message to an AI model and pay per call using USDC on Base: 'Summarize the pros and cons of electric vehicles in three bullet points.'

## When to prefer this

Choose this endpoint when you need OpenAI-compatible chat completions with zero account setup, preferring crypto (USDC on Base) micropayment via x402 over subscription billing. Ideal for agents, bots, or scripts that need anonymous, pay-as-you-go LLM inference at $0.001–$0.01 per call without managing API keys or monthly plans.

## Known failure modes

- 402 Payment Required if no valid x402 payment is attached — returns PAYMENT-REQUIRED header and JSON challenge body
- Request below $0.01 minimum charge may be rounded up to minimum
- Invalid or expired payment transaction rejected
- Malformed JSON body returns 400 Bad Request
- Network congestion on Base may delay payment confirmation
- Model not found if requested model is not in catalogue

## How this service works

OpenAI-compatible inference paid per request in USDC on Base (eip155:8453, scheme exact). GET /v1/models for the model catalogue and per-model USD prices. Every paid route answers unauthenticated requests with an x402 v2 402 challenge (PAYMENT-REQUIRED header + JSON body). Minimum charge $0.01 per paid call on chat/completions and tts (usage-based price applies above it); credit top-ups are $1 minimum. Contact: weare@linkrra.com Pay-per-call needs no account and no API key: POST /v1/chat/completions with no Authorization header returns the x402 402 challenge and accepts payment in place.

## Output

Returns a standard OpenAI-style chat completion JSON object including an id, choices array with the assistant message and content, token usage breakdown (prompt, completion, total tokens), and a payment sub-object confirming the network (eip155:8453), amount paid in USD, and on-chain transaction hash.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "model": {
   "enum": [
    "auto",
    "qwen/qwen3-vl-30b-a3b-instruct",
    "qwen/qwen3-30b-a3b",
    "qwen3-coder-30b",
    "gpt-oss-20b",
    "gemma-4-26b-a4b-it"
   ],
   "type": "string",
   "description": "\"auto\" = cheapest of our self-hosted models that fits, or name one."
  },
  "stream": {
   "type": "boolean",
   "default": false,
   "description": "true = stream OpenAI-format Server-Sent Events."
  },
  "messages": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "role",
     "content"
    ],
    "properties": {
     "role": {
      "enum": [
       "system",
       "user",
       "assistant",
       "tool"
      ],
      "type": "string"
     },
     "content": {
      "description": "Text, or an array of OpenAI content parts."
     }
    }
   },
   "examples": [
    [
     {
      "role": "user",
      "content": "Write a Python function that reverses a string"
     }
    ]
   ],
   "minItems": 1,
   "description": "OpenAI-format chat history, oldest first: [{role, content}]."
  },
  "max_tokens": {
   "type": "integer",
   "default": 4096,
   "maximum": 4096,
   "minimum": 1,
   "description": "Completion token cap. The price is quoted for the prompt plus this cap."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "id": "chatcmpl-...",
  "usage": {
   "total_tokens": 0,
   "prompt_tokens": 0,
   "completion_tokens": 0
  },
  "object": "chat.completion",
  "choices": [
   {
    "message": {
     "role": "assistant",
     "content": "..."
    }
   }
  ],
  "payment": {
   "network": "eip155:8453",
   "paidUsd": 0,
   "transaction": "0x..."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/linkrra-pearl-pool-chat-completions-e27aec76/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from pool.linkrra.com](https://www.zero.xyz/host/pool.linkrra.com/llms.txt)