> ## Documentation Index
> Fetch the complete documentation index at: https://docs.molpha.io/llms.txt
> Use this file to discover all available pages before exploring further.

# FAQ

**Is there a protocol token?**
No. Subscriptions are paid in USDC on Solana; there is no governance token and no token-price exposure.

**Do I need a subscription to read a feed?**
No. Reading any Solana `Feed` account is permissionless and free. A subscription is only required to maintain your own feeds.

**Do AI agents need subscriptions?**
Not always. Agents have two options: a [Delegate](/access-models/delegates) under an existing subscription, or [x402 escrow](/access-models/x402) pay-per-request with no monthly plan.

**What is x402 used for?**
x402 is the HTTP payment loop for the agent escrow path. The client funds a per-gateway `AgentEscrow` ATA; if underfunded, the gateway returns a `402 Payment Required` envelope with where and how much to pay.

**Do I need to change my contract to consume Molpha on EVM?**
One external call: `require(verifier.verify(update, sig))`, plus your own staleness check. No inheritance, no interface to implement.

**Why does the same signature work on every chain?**
The signed message contains no `chainId`, and every verifier (Solidity, Cairo, the Solana program) checks the identical domain-separated message with the identical selection and aggregation rules. The Starknet port is proven with parity tests that accept unmodified EVM-produced signatures.

**Who keeps a Solana feed updated?**
`submit_data_update` is permissionless — nodes, gateways, or your own keeper can push signed values. The program re-verifies the aggregate signature on every write, so the submitter doesn't affect trust.

**Does the verifier protect me from stale or replayed data?**
No — by design. Historical registry versions remain verifiable forever. Enforce freshness against `canonicalTimestamp` and replay protection in your own contract.

**Is Molpha Chainlink (AggregatorV3) compatible?**
No, by design. Consumers call `verify()` directly with a self-contained payload. There is no aggregator product.

**Is the protocol audited?**
Not yet. The current deployments are pre-audit testnet contracts with a permissioned node set; mainnet is gated on a full audit.