Quickstart: Smart contracts

Your contract receives an attestation (a signed payload plus one aggregate signature) and checks it on-chain. You don’t run a node, trust a relayer, or deploy a feed contract per chain. The same attestation works on every chain below.

EVM
Starknet
Solana

Install the interface with Foundry:

forge install molpha/evm-verifier@chivchyn
echo "@molpha/evm-verifier/=lib/evm-verifier/src/" >> remappings.txt

Call verify and apply your own policy:

import {IVerifier} from "@molpha/evm-verifier/interfaces/IVerifier.sol";

error NotVerified(uint8 code);

function settle(IVerifier.Attestation calldata att) external {
    (bool ok, uint8 code) = VERIFIER.verify(att, 60); // maxAge in seconds
    if (!ok) revert NotVerified(code);
    require(att.payload.sourceId == EXPECTED_SOURCE_ID, "wrong source");
    require(att.payload.signaturesRequired >= MIN_SIGNATURES, "threshold too low");
    // guard replay, then decode att.payload.value
}

verify returns (false, code) instead of reverting, so always check ok. Full guide, consumer library and result codes: Verify on EVM.

Call the Cairo verifier through its dispatcher:

use verifier::interface::{Attestation, IVerifierDispatcher, IVerifierDispatcherTrait};

let (ok, _code) = IVerifierDispatcher { contract_address: verifier }.verify(attestation, 60);
assert(ok, 'molpha: not verified');
assert(attestation.payload.source_id == EXPECTED_SOURCE, 'molpha: wrong source');
assert(attestation.payload.signatures_required >= MIN_SIGNATURES, 'molpha: low threshold');

Full guide: Verify on Starknet.

Read the latest value from a Feed account that a submitter keeps up to date, after checking its address:

#[account(
    seeds = [b"molpha_feed", source_id.as_ref(), &[signatures_required], submitter.as_ref()],
    bump,
    seeds::program = MOLPHA_PROGRAM_ID,
)]
pub molpha_feed: AccountInfo<'info>,

Or verify an attestation directly in your program with the molpha-verifier crate. Both patterns, with a staleness guard: Verify on Solana.

Get an attestation to test with

Request one from a backend with the SDK or from an agent with MCP. The SDK builds the calldata for you:

import { buildEvmVerifierArgs, buildStarknetVerifierArgs } from "@molpha/sdk";

const evmArgs = buildEvmVerifierArgs(attestation, { maxAge: 60 });
const starknetArgs = buildStarknetVerifierArgs(attestation, { maxAge: 60 });

Verifier addresses for each network are on Deployments.

Before you ship

Verification proves that enough selected nodes signed this exact payload. Your contract still owns the rest:

Pin the sourceId you expect and require a minimum signaturesRequired.
Enforce freshness: a non-zero maxAge on EVM and Starknet, or compare timestamp / 1000 with the chain clock.
Reject replays when an old attestation could be submitted twice.
Decode value with the source’s encoding and bound-check it.

The full list is the consumer checklist.

Get started

Concepts

Access and payments

MCP server

Verify and publish

Protocol

Resources

Quickstart: Smart contracts

Get an attestation to test with

Before you ship

​Get an attestation to test with

​Before you ship

Get an attestation to test with

Before you ship