# ICP Agent Marketplace - AI Prompt Service

> ICP Agent Marketplace - AI Prompt Service is a paid API for AI agents from icp-agent-marketplace.ngrok.app, paid per call via x402, $0.028/call, status unknown (last checked 2026-09-14).

Submits a natural language prompt to autonomous ICP canisters and returns an AI-generated response on a pay-per-query basis with no account required.

## Facts

- Endpoint: GET https://icp-agent-marketplace.ngrok.app/api/agent-service
- Price: $0.028/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/icp-agent-marketplace-ai-prompt-service-58e1f5dd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_TaXcRa6sRbuBFSTbhp1Od

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 icp-agent-marketplace-ai-prompt-service-58e1f5dd
```

Example prompt: Ask the ICP agent marketplace to explain what zero-knowledge proofs are — it's pay-per-query on decentralized canister infrastructure, no account needed.

## When to prefer this

Choose this endpoint when you need on-demand AI text generation without account creation or API key management, and are comfortable with pay-per-query USDC micropayments via the x402 protocol. It is well-suited for agents operating in decentralized or blockchain-native contexts, particularly those interacting with the Internet Computer Protocol ecosystem. Prefer this over traditional AI APIs when you want redundant, canister-backed infrastructure or when your workflow requires trustless, permissionless AI access.

## Known failure modes

- Missing required 'input' field returns a validation error
- Payment not completed or x402 payment protocol failure results in a 402 Payment Required response
- Canister unavailability or ICP network issues may cause timeouts or 503 errors
- Malformed query parameters cause request rejection
- ngrok tunnel downtime may render the endpoint temporarily unreachable

## How this service works

On-demand AI responses backed by autonomous ICP canisters. Submit a prompt, get an answer — redundant infrastructure, pay-per-query, no account required.

## Output

A natural language AI-generated text response answering the submitted prompt, returned directly from autonomous ICP canisters. The response is produced on demand without requiring account registration, with the $0.028 USDC fee charged per successful query.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/icp-agent-marketplace-ai-prompt-service-58e1f5dd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from icp-agent-marketplace.ngrok.app](https://www.zero.xyz/host/icp-agent-marketplace.ngrok.app/llms.txt)