MCP server Molpha

Molpha MCP

A Model Context Protocol (MCP) server that lets AI agents fetch signed Molpha oracle data, publish it on Solana, and build verifier calldata for EVM and Starknet.

Molpha turns HTTP API responses into threshold-signed payloads that can be verified on Solana, EVM, and Starknet. This server exposes that workflow as MCP tools, with signing behind a local, Privy, or Turnkey wallet, or, on mcp.molpha.io, behind your own wallet.

[!WARNING] This release targets Solana Devnet and Sepolia verifier networks. Treat it as testnet software, not a production security boundary. Write tools spend SOL, and round tools may consume subscription quota or pay USDC for x402 rounds, unless dry-run mode is enabled.

Quick start

Two recommended ways to connect:

	mcp.molpha.io	Local (stdio)
Install	Nothing: add the URL to your client	npx, Node.js 24 or later
Signer	Your own wallet. The server holds no key.	Local keypair, Privy or Turnkey, held by the server
Subscription rounds	Sign in with SIWX, then execute_subscription_round	execute_subscription_round
Spending limits	Your wallet's own policy	Dry-run lock and daily caps in the server
Best for	Getting started, agents that bring their own wallet	Unattended agents, private API sources

mcp.molpha.io

Nothing to install, and no keys to hand over. Add the URL to your client.

Claude Code:

claude mcp add --transport http molpha https://mcp.molpha.io/mcp

Cursor (.cursor/mcp.json):

{ "mcpServers": { "molpha": { "url": "https://mcp.molpha.io/mcp" } } }

The read tools work straight away. The server has no wallet of its own, so name the one you mean: submitter for describe_feed and get_latest_value, payer for get_x402_status.

Anything that needs a signature is returned for your own wallet to sign, so each such operation is two or three tool calls around one signature:

Operation	Tools, in order	The wallet signs
Subscription round	begin_session → complete_session → execute_subscription_round	A text message, once per session
x402 round	prepare_x402_round → execute_x402_round	A USDC transfer, not broadcast
Solana submit	prepare_submit_attestation → send_signed_transaction	The submit transaction

autoSubmit, dryRun and encryptSecrets are not offered here. Set spending limits in the wallet's own policy, and use the local server for private API work.

Sign in with your wallet (SIWX)

A subscription round on mcp.molpha.io is authorized by a sign-in session: the wallet signs one Sign-In-With-X text message (the x402 sign-in-with-x extension, in its Solana form), and the gateway issues a short-lived bearer token. The message is not a transaction and moves no funds.

Step	Call	Result
1	describe_access({ address, owner? })	Whether the wallet is a subscription owner or delegate, and its limits
2	begin_session({ address, owner? })	The message to sign and an opaque challenge
3	The wallet signs message	An Ed25519 signature over its exact UTF-8 bytes
4	complete_session({ challenge, signature })	A sessionToken and its expiresAt
5	execute_subscription_round({ sessionToken, apiConfig, signaturesRequired, chains })	The signed attestation and verifier arguments

• Who can sign in. The subscription owner, or a delegate the owner added with add_delegate. A delegate passes the owner's address as owner.
• How to sign. The message as returned: raw UTF-8, no prefix, no envelope, no trailing newline. The signature may be base58, base64 or hex. solana sign-offchain-message wraps the text and is refused with invalid_signature.
• What the token is. A credential for one wallet and one gateway, valid 30 minutes by default and never past the subscription term. It only identifies the caller: the gateway re-reads the subscription and delegate from chain on every round, so remove_delegate ends access whatever tokens exist. It passes through this server and is never stored or logged.
• What it needs. A gateway with sessionAuth: true in GET /v1/info. Otherwise begin_session answers sessions_unavailable and x402 rounds remain available.

The full walkthrough, with a signing example, delegate setup, gateway routes and error codes, is in docs/integration.md.

Local (stdio)

The server runs on your machine and holds the signer, so one tool call runs a round or submits to Solana, and MOLPHA_DRY_RUN keeps every write a preview until you turn it off.

Needs Node.js 24 or later. Nothing to clone or build.

1. Look around, no wallet. Read-only: capabilities, providers, sourceIds, prices, feed values.

claude mcp add molpha -- npx -y @molpha/mcp@0.2.0 --read-only

2. Build with a testnet wallet. Put your signer settings in a .env file (see Setup), then check them. The doctor prints a ready-to-paste config for your client, with secrets left as placeholders:

npx -y @molpha/mcp@0.2.0 doctor

A config like this keeps every write a preview (MOLPHA_DRY_RUN=true):

claude mcp add molpha -e SIGNER_BACKEND=keychain -e KEYCHAIN_BACKEND=privy -e PRIVY_APP_ID='<privy-app-id>' -e PRIVY_APP_SECRET='<privy-app-secret>' -e PRIVY_WALLET_ID='<privy-wallet-id>' -e PRIVY_WALLET_ADDRESS='<base58-solana-address>' -e MOLPHA_DRY_RUN=true -- npx -y @molpha/mcp@0.2.0

3. Spend only when you mean to: fund the wallet, then set MOLPHA_DRY_RUN=false in the server's config. The full guide, with Cursor, VS Code, Codex and Claude Desktop, is docs/integration.md.

With no signer configured the server starts read-only and offers only the read tools (runLevel: "read-only" in get_capabilities). --read-only or SIGNER_BACKEND=none forces it.

Tools

Tool	Access	Description
get_capabilities	Read	Run level, program id, registry version, nodes, gateways, chains, verifier addresses, x402 caps and source-payment policy.
derive_source_id	Read, local	Derive an apiConfig's sourceId (how). No transaction, no wallet.
describe_feed	Read	Read the Solana feed for (sourceId, signaturesRequired, submitter) and the signer's subscription status.
get_latest_value	Read	Read the latest attested value stored in a Solana feed account.
describe_access	Read	Whether a wallet is a subscription owner or delegate, with the plan's and the delegate's limits.
get_x402_status	Read	Quote the next x402 round, show where payment goes, and read a payer's USDC balance and remaining daily budget.
list_providers	Read	The data providers the gateway integrates and the flows it serves (providers).
get_provider	Read	One provider's flows, disclosure and ready-made feeds, each with a complete apiConfig and sourceId.
quote_source_payment	Read	Price a paywalled source with one unpaid request, including the worst-case total.
execute_subscription_round	Spends quota	Run a round paid from a USDC subscription; return the signed attestation plus verifier arguments. autoSubmit: true settles Solana in the same call.
execute_x402_round	Spends USDC	Run a round paid per request over x402; same output.
build_verifier_calldata	Read, local	Build EVM/Starknet verifier address and verify() call arguments. Calldata only: it verifies nothing.
submit_attestation	Write	Submit a signed attestation to Solana. Accepts a round tool's output unmodified.

On mcp.molpha.io the one-call round and submit tools become prepare/sign/execute pairs (above). Every tool returns structuredContent and carries MCP annotations; see Structured output and annotations. For tolerance-mode aggregation and the full configuration table, see docs/reference.md.

Round timing. Rounds run on a fixed 100 ms tick. Requests for one feed (the same source and quorum) inside one tick share a round, so a feed runs at most 10 rounds per second, and one wallet gets at most one round per tick for a feed: a second request in the same tick is answered with HTTP 409, which the round tools retry a tick later before failing with round_conflict. See Round timing.

Setup

For the local server.

Signer. Put your settings in a .env file and check them with the doctor. It prints a ready-to-paste config for your client with secrets left as placeholders. Use a dedicated testnet wallet.

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

Privy and Turnkey settings are in docs/reference.md and .env.example.

npx -y @molpha/mcp@0.2.0 doctor

Dry-run lock. MOLPHA_DRY_RUN=true locks execute_subscription_round, execute_x402_round and submit_attestation to previews. A call with dryRun: false is refused with dry_run_locked, so going live is a change to the server's config, never to one tool call.

Subscription. Subscribing debits USDC, so it is kept out of the MCP tools and runs as a CLI command with the same signer configuration. --max-price-usdc is a cap in USDC base units (6 decimals); drop --dry-run to subscribe, or use extend to extend one.

npx -y @molpha/mcp@0.2.0 provision subscribe --plan Basic --max-price-usdc 20000000 --dry-run

Client. Every client launches the local server with npx. Snippets for Claude Code, Cursor, VS Code, Codex and Claude Desktop are in docs/integration.md, ready-to-edit copies are in examples, and Claude Desktop users can install the molpha-mcp.mcpb bundle attached to each release.

Example prompts

Discover. Use Molpha to inspect the current oracle capabilities. Summarize the registry version, node count, chains, gateways, and verifier addresses. Make no writes.

Derive. Derive a Molpha sourceId for https://api.example.com/v1/finalized/price using the JSON path $.price. Show me the canonical JSON and the sourceId. Do not send a transaction.

Fetch. For that source, run a subscription round with 3 signatures for the EVM chain. Summarize the value, timestamp, registry version and verifier call. Treat the signed attestation as the trust anchor, not the value alone.

Provider. List the integrated data providers, describe TickerLayer's btcusd feed, and run it with 3 signatures for Solana, passing the apiConfig exactly as given.

Check spend. Call get_x402_status for 3 signatures. Tell me the price, where payment goes, and my USDC balance before I authorize an execute_x402_round.

Publish. If I give you a newer signed attestation, preview submit_attestation with dryRun: true, explain the exact write, and wait for my confirmation before submitting.

Use a public endpoint that returns stable, independently reproducible data: live ticker endpoints may differ across oracle nodes and fail to reach quorum.

How it works

flowchart LR
    Client["MCP client"] <-->|"stdio / HTTP"| Server["Molpha MCP server"]
    Server --> Guardrails["Dry-run · daily caps · spend caps"]
    Server --> Signer["Signer adapter<br/>local · Privy · Turnkey"]
    Server --> SDK["Molpha SDK / x402 client"]
    SDK --> Gateway["Molpha gateway"]
    Gateway <--> Nodes["Oracle node quorum"]
    SDK <--> Solana["Solana program<br/>feeds · subscriptions"]
    Gateway --> Artifact["Threshold-signed attestation"]
    Artifact --> Server
    Server --> Args["EVM / Starknet verifier args,<br/>or submit_attestation on Solana"]

The server is an adapter and policy boundary, not a new source of truth. Oracle nodes independently fetch the committed API configuration and produce one aggregate signature after reaching quorum; the server returns that self-contained signed artifact. Consumers trust a value only after verifying the signed payload against its registry version.

Development

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

Point a client at the built server with node /absolute/path/to/mcp/dist/src/server.js.

npm run dev          # start from TypeScript
npm run typecheck && npm test && npm run build   # run before opening a pull request
npm run gen:install  # rewrite the generated install snippets in the docs and examples
npm run smoke:pack   # pack the tarball and run it with npx over stdio (needs network)
npm run pack:mcpb    # build the Claude Desktop bundle from an allowlist

@molpha/sdk is pinned to an exact version and resolved from the npm registry; to try a local checkout run npm install ../sdk and do not commit the result. Install snippets are generated from src/install-config.ts: edit the renderers, not the generated text, because npm test fails when a generated file is out of date.

Versioning and publishing use Changesets: if a pull request changes published behavior, run npx changeset. On merge to main, release.yml opens a "Version Packages" PR and, when that merges, publishes @molpha/mcp to npm (trusted publishing, no token) and server.json to the MCP registry.

Bug reports and focused pull requests are welcome. For security issues, use GitHub's private vulnerability reporting instead of a public issue.

Documentation

• Integration guide: install per client, spending, signing in with your own wallet (SIWX), and running the HTTP server yourself
• Reference: sourceId, tolerance mode, x402, providers, configuration, signers
• Molpha protocol documentation
• Client configuration examples and the MCPB manifest

License

Released under the MIT License.