# Agent Exchange — AI Agent Messaging Endpoint

> Agent Exchange — AI Agent Messaging Endpoint is a paid API for AI agents from store.agentexchange.work, paid per call via x402, $0.09/call, status unknown (last checked 2026-09-14).

Sends a natural-language message to an AI agent via POST and receives a response, paid per-call in USDC via x402 on Base.

## Facts

- Endpoint: POST https://store.agentexchange.work/einstein/ai-agent/v1/agents/messages
- Price: $0.09/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-exchange-ai-agent-messaging-endpoint-e30aaaef
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_KT0UqJhoGJa4V-CelwHEh

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 agent-exchange-ai-agent-messaging-endpoint-e30aaaef -d '<json body>'
```

Example prompt: Send the message 'What is the current ETH price?' to the Agent Exchange AI agent endpoint and return whatever the agent says back.

## When to prefer this

Choose this endpoint when you need to send a natural-language message to an AI agent and receive a response without API keys or signup, and you can pay per-call in USDC via x402 on Base. Ideal for agentic workflows, agent-to-agent communication, or one-off queries to autonomous agents within the Agent Exchange ecosystem.

## Known failure modes

- Payment failure: insufficient USDC balance or x402 payment not accepted, resulting in 402 response
- Missing required 'message' query parameter causes validation error
- Invalid 'type' or 'method' fields in input object return schema validation errors
- Agent backend unavailable returns error status in response body
- Malformed JSON in request body causes 400 Bad Request

## How this service works

Machine-payable data APIs for AI agents across web search, on-chain reads, trading data, market judgment, and AI visibility. The canonical x402 catalog currently exposes 85 paid routes. Pay per call in USDC via x402 on Base. No API keys, no signup.

## Output

Returns a JSON object with a status field (e.g. 'Premium Fallback Node Active') and any agent-generated response content corresponding to the submitted message.

## 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": [
      "POST"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "message"
     ],
     "properties": {
      "message": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "status": "Premium Fallback Node Active"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-exchange-ai-agent-messaging-endpoint-e30aaaef/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from store.agentexchange.work](https://www.zero.xyz/host/store.agentexchange.work/llms.txt)