Quickstart: Maintain a Feed

This page shows the subscription-backed producer path. There is no create-feed transaction: derive feedId, request signed data, and the first successful submit creates the Solana Feed account lazily.

AI Agents

First verified request through MCP — then Delegate or x402 escrow.

Smart Contracts

Verify a Molpha payload inside your app.

Backends

Request signed data with the TypeScript SDK.

Both legacy paths below reach the same outcome: a threshold-signed value verified on Solana Devnet. Pick the one that matches how you work.

Prerequisites

A Solana wallet with Devnet SOL
Devnet USDC for the subscription — use Circle’s faucet (select USDC on Solana Devnet)
Node.js >=20.19.0 for the SDK and >=24.0.0 for the MCP server

Current releases target Solana Devnet and Sepolia verifier networks. Write operations spend Devnet SOL and may consume subscription quota.

MCP server

The MCP server exposes typed tools for AI agents over stdio. Full tool reference, architecture, guardrails, and troubleshooting live on that page.

Clone, build, and configure

git clone https://github.com/Molpha/mcp.git
cd mcp
npm ci
cp .env.example .env
npm run build

For local development, set a memory signer and Solana RPC in .env:

SIGNER_BACKEND=memory
OWNER_KEYPAIR=/absolute/path/to/owner-keypair.json
SOLANA_RPC=https://api.devnet.solana.com
GATEWAY_ENDPOINTS=

Leave GATEWAY_ENDPOINTS empty to use the SDK default. The same wallet must subscribe, own feeds, and sign gateway auth messages. For Privy or Turnkey, see signer configuration.

Validate and subscribe

npm run doctor
npm run provision -- subscribe --plan Basic --max-price-usdc 20000000 --dry-run
npm run provision -- subscribe --plan Basic --max-price-usdc 20000000

npm run doctor prints MCP client snippets with resolved absolute paths. 20000000 is 20 USDC at 6 decimals — a safety cap that aborts if the on-chain price is higher.

Connect your MCP client

Add the compiled server to your client config, restart, and call molpha_get_capabilities. Use absolute paths — clients may start the server from a different working directory.

Cursor / Claude Desktop
Codex

{
  "mcpServers": {
    "molpha": {
      "command": "node",
      "args": ["/absolute/path/to/mcp/dist/src/server.js"],
      "env": {
        "SIGNER_BACKEND": "memory",
        "OWNER_KEYPAIR": "/absolute/path/to/owner-keypair.json",
        "SOLANA_RPC": "https://api.devnet.solana.com"
      }
    }
  }
}

[mcp_servers.molpha]
command = "node"
args = ["/absolute/path/to/mcp/dist/src/server.js"]

[mcp_servers.molpha.env]
SIGNER_BACKEND = "memory"
OWNER_KEYPAIR = "/absolute/path/to/owner-keypair.json"
SOLANA_RPC = "https://api.devnet.solana.com"

Try an agent prompt

Ask your client to inspect the network (read-only):

Use Molpha to inspect the current protocol capabilities. Summarize the registry version, node count, supported chains, and gateway endpoints. Do not make any writes.

More example prompts are on the MCP server page.

Subscription and extension operations stay in the provisioning CLI because they debit USDC. They are not exposed as MCP tools.

TypeScript SDK

Install @molpha/sdk v0.1.0 and wire the gateway and Solana clients behind one wallet. The SDK overview covers the full API surface.

Install

pnpm
npm
yarn

pnpm add @molpha/sdk @anchor-lang/core bn.js

npm install @molpha/sdk @anchor-lang/core bn.js

yarn add @molpha/sdk @anchor-lang/core bn.js

Initialize, subscribe, and derive a feed

import { web3 } from "@anchor-lang/core";
import {
  MolphaSDK,
  PlanType,
  deriveApiConfigHash,
  deriveFeedIdString,
} from "@molpha/sdk";
import { walletFromKeypairFile } from "@molpha/sdk/utils";

const wallet = walletFromKeypairFile("~/.config/solana/id.json");
const sdk = new MolphaSDK({
  connection: new web3.Connection("https://api.devnet.solana.com", "confirmed"),
  wallet,
});

const plan = await sdk.solana.getPlan(PlanType.Basic);
await sdk.solana.subscribe(PlanType.Basic, {
  maxPriceUsdc: plan.subscriptionPrice,
});

const apiConfig = {
  url: "https://api.example.com/price",
  responseParser: "$.price",
};

const signaturesRequired = 3;
const feedId = deriveFeedIdString(
  wallet.publicKey.toBytes(),
  deriveApiConfigHash(apiConfig),
  signaturesRequired,
);

Request a signed result and submit

const { result, signature } = await sdk.requestAndSubmit(feedId, {
  apiConfig,
  signaturesRequired,
});
console.log("Submitted:", signature);
console.log("Gateway value:", result.value);

const feed = await sdk.solana.readFeed(feedId);
console.log("On-chain value bytes:", feed?.value);
console.log("Timestamp:", feed?.canonicalTimestamp);

Gateway execution requires a signAuthMessage-capable wallet. The gateway verifies a real Ed25519 authSig and rejects all-zero signatures.

Next steps

Maintain a feed

Producer flow: subscriptions, feed constraints, and keeping feeds current.

Read and verify

Consumer flow: read cached feeds or verify fresh signed payloads.

MCP server reference

Tool reference, architecture, guardrails, and troubleshooting.

SDK reference

Types, methods, and EVM/Starknet argument builders.

Get Started

Quickstarts

AI Agents

Access Models

Core Concepts

Guides

Gateways

Verifiers

Protocol

Reference

Resources

Quickstart: Maintain a Feed

AI Agents

Smart Contracts

Backends

Prerequisites

MCP server

TypeScript SDK

Next steps

Maintain a feed

Read and verify

MCP server reference

SDK reference

AI Agents

Smart Contracts

Backends

​Prerequisites

​MCP server

​TypeScript SDK

​Next steps

Maintain a feed

Read and verify

MCP server reference

SDK reference

Prerequisites

MCP server

TypeScript SDK

Next steps