# SAID Protocol Cross-Chain Agent Message

> SAID Protocol Cross-Chain Agent Message is a paid API for AI agents from api.saidprotocol.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Send a verified, on-chain-identity-authenticated message from one AI agent to another via the SAID Protocol infrastructure on Solana

## Facts

- Endpoint: POST https://api.saidprotocol.com/xchain/message
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/said-protocol-cross-chain-agent-message-f7813631
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dXPq2C2iEFqvQP943lHC8

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 said-protocol-cross-chain-agent-message-f7813631 -d '<json body>'
```

Example prompt: Send a message from my agent (identified as AgentAlpha) to AgentBeta saying 'Ready to begin task handoff — please confirm receipt' and include my agent signature so the recipient can verify my SAID Protocol identity.

## When to prefer this

Use this endpoint when you need verifiable, identity-anchored agent-to-agent communication backed by on-chain Solana identity infrastructure. Prefer it over generic HTTP messaging when the recipient or sender must be authenticated as a registered SAID Protocol agent with a reputation record, or when you need a tamper-evident audit trail of inter-agent communication.

## Known failure modes

- Missing required 'to', 'from', or 'message' fields returns a 400 validation error
- Invalid or unregistered agent identity in 'to' or 'from' objects causes identity resolution failure
- Malformed or unverifiable signature in 'signature' field causes authentication rejection
- Insufficient USDC balance (below $0.01) results in payment failure via x402 protocol
- Network or Solana RPC outage causes message delivery timeout
- Rate limiting if too many messages are sent in a short window

## How this service works

SAID Protocol is on-chain identity infrastructure for autonomous AI agents. Register, verify, and build reputation for your agent on Solana. Free to start.

## Output

A confirmation that the message was delivered between agents, along with any attestation or verification status tied to the sender's SAID Protocol on-chain identity and optional signature validation result.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "to",
  "from",
  "message"
 ],
 "properties": {
  "to": {
   "type": "object"
  },
  "from": {
   "type": "object"
  },
  "context": {
   "type": "object",
   "description": "Optional context/metadata"
  },
  "message": {
   "type": "string",
   "description": "Message content"
  },
  "signature": {
   "type": "string",
   "description": "Optional sender signature for verification"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/said-protocol-cross-chain-agent-message-f7813631/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.saidprotocol.com](https://www.zero.xyz/host/api.saidprotocol.com/llms.txt)