Metaplex API - Mint Agent | REST API

Build a transaction that mints an MPL Core asset for your agent and registers its identity with the Agent Registry in one step. The API stores the agent metadata off-chain and returns a partially signed transaction for the wallet to co-sign as payer.

Summary

This is the endpoint behind the Mint an Agent guide.

Creates the Core asset and calls registerIdentity in a single transaction
The asset keypair is generated server-side and pre-signed, so the response includes the final assetAddress
Stores the EIP-8004 metadata and a hosted A2A AgentCard (yours, or synthesized from the metadata)
The caller's wallet signs as payer and submits the transaction

Quick Reference

Item	Value
Method	`POST`
Path	`/agents/mint`
Auth	None
Response	Serialized transaction + `assetAddress`

Endpoint

POST /agents/mint

Request Body

Field	Type	Required	Description
`wallet`	`string`	Yes	Wallet that will pay for and own the agent (base58).
`network`	`string`	Yes	`solana-mainnet` or `solana-devnet`.
`name`	`string`	Yes	Agent name for the Core asset.
`uri`	`string`	Yes	URI of the asset's off-chain JSON metadata.
`agentMetadata`	`object`	Yes	EIP-8004 agent registration JSON (name, description, image, services, registrations, active, …).
`collectionAddress`	`string`	No	Core collection to mint the agent into.
`a2aCard`	`object`	No	Pre-built A2A AgentCard. When omitted, one is synthesized from `agentMetadata`.

Example Request

curl -X POST "https://api.metaplex.com/v1/agents/mint" \
  -H "Content-Type: application/json" \
  -d '{
    "wallet": "4Nd1mYvJ9jVexjIXG5oJhanoGWyF7Cz6XkY8dEc4RsyG",
    "network": "solana-devnet",
    "name": "Example Agent",
    "uri": "https://example.com/agent-metadata.json",
    "agentMetadata": {
      "name": "Example Agent",
      "description": "An autonomous trading agent.",
      "active": true,
      "services": [],
      "registrations": []
    }
  }'

Response

{
  "success": true,
  "tx": "<base64-encoded partially signed transaction>",
  "blockhash": {
    "blockhash": "9WzDXwBbmkg8ZTbNMqUxvQRAyrZzDsGYdLVL9zYtAWWM",
    "lastValidBlockHeight": 123456789
  },
  "assetAddress": "7nE9GvcwsqzYcPUYfm5gxzCKfmPqi68FM7gPaSfG6EQN"
}

Signing and Submitting

The returned transaction is already signed by the asset keypair; your wallet co-signs as payer and submits:

import { base64 } from "@metaplex-foundation/umi/serializers";

const res = await fetch("https://api.metaplex.com/v1/agents/mint", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify(input),
});
const result = await res.json();
if (!result.success) throw new Error(result.error);

const tx = umi.transactions.deserialize(base64.serialize(result.tx));
const signed = await umi.identity.signTransaction(tx);
await umi.rpc.sendTransaction(signed);

Errors

Status	Body	Meaning
`400`	`{ "success": false, "error": "Invalid input data", "details": [...] }`	Request body failed validation; `details` lists the issues.
`400`	`{ "success": false, "error": "<message>" }`	Build failure (e.g. collection not found).
`500`	`{ "success": false, "error": "Failed to prepare mint agent" }`	Server error.

Notes

The Metaplex registry entry (solana:101:metaplex) is automatically added to the front of agentMetadata.registrations.
A hosted A2A service entry is spliced into services[] so EIP-8004 consumers can discover the AgentCard endpoint; this is a no-op if you already authored one.
The agent record is stored when you call this endpoint, but it only appears in List Agents once the signed transaction has been confirmed and indexed.
For a guided walkthrough with the SDK, see Mint an Agent.