> ## 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.

# Payload Schema

> Field-level reference for Molpha's portable signed data artifact.

Every Molpha round returns a signed artifact that maps onto the same logical schema across Solana, EVM, Starknet, SDK, and MCP surfaces.

## Logical schema

### `DataUpdate`

| Field                | Type               | Meaning                                                          |
| -------------------- | ------------------ | ---------------------------------------------------------------- |
| `feedId`             | `bytes32`          | Feed identity derived from owner, API config hash, and quorum    |
| `registryVersion`    | `u32`              | Immutable node-set snapshot used for verification                |
| `signaturesRequired` | `u32`              | Minimum signer threshold for this round                          |
| `value`              | `bytes32` / `u256` | Canonical result, encoded as a 32-byte big-endian word           |
| `canonicalTimestamp` | `u64`              | Unix seconds for the round; signed and used for freshness checks |

### `SchnorrSignature`

| Field                           | Type                                | Meaning                                          |
| ------------------------------- | ----------------------------------- | ------------------------------------------------ |
| `signature` / `s`               | `bytes32`                           | Aggregate Schnorr scalar                         |
| `commitment` / `commitmentAddr` | `address` / felt-compatible address | Ethereum-style address of the nonce commitment   |
| `signersBitmap`                 | `u256` / `bytes32`                  | Bitmap of participating 1-based registry indices |

## SDK response shape

```ts theme={null}
interface DataUpdateResult {
  feedId: string;
  value: string;
  valuePacked: string;
  timestamp: number;
  registryVersion: number;
  signaturesRequired: number;
  signersBitmap: string;
  s: string;
  commitmentAddr: string;
  fresh: boolean;
}
```

## Signed message

```text theme={null}
message = keccak256(abi.encodePacked(
  MESSAGE_PREFIX,
  feedId,
  registryVersion,
  signaturesRequired,
  signersBitmap,
  value,
  canonicalTimestamp
))
```

`signersBitmap` is inside the message, so the caller cannot choose a signer set after signature aggregation. `chainId` is not inside the message, so the same payload can verify on all supported chains.

## Consumer rules

* Treat `value` as bytes until your application decodes it.
* Enforce `feedId` equality against the feed you intended.
* Enforce freshness against `canonicalTimestamp`.
* Add replay protection when a valid old payload could be submitted twice.
* Require the verifier result before executing application logic.

## Chain-specific references

<CardGroup cols={3}>
  <Card title="Solana" icon="sun" href="/verifiers/solana">
    Program verification and feed account details.
  </Card>

  <Card title="EVM" icon="ethereum" href="/verifiers/evm">
    Solidity structs and verifier call pattern.
  </Card>

  <Card title="Starknet" icon="hexagon-nodes" href="/verifiers/starknet">
    Cairo structs and syscall-based secp256k1 verification.
  </Card>
</CardGroup>