| Feed | Application-facing data source backed by a deterministic feedId and signed payloads. It may also have a maintained Solana Feed account. |
Solana Feed account | Account holding the latest verified value for a feed; PDA ["molpha_feed", feed_id]. |
| Round | One coordination event: one fetch, one signing session, one aggregate signature. |
| DataUpdate | The self-contained signed result payload: feedId, registryVersion, signaturesRequired, value, canonicalTimestamp. |
| Canonical timestamp | The round timestamp included in the signed message; the basis for staleness checks. |
| Registry version | An immutable snapshot of the node-key set; incremented on every add/remove. |
| Selection set | The pseudo-random subset of nodes eligible to sign a given round, derived from (feedId, registryVersion, canonicalTimestamp). |
| Group size | signaturesRequired + redundancyBuffer, capped at nodeCount; the size of the selection set. |
| Redundancy buffer | Admin parameter widening the selection set beyond the threshold so dropouts don’t fail the round. |
| Signers bitmap | A 256-bit word where bit i-1 marks 1-based node index i as a signer; bound into the signed message. |
| Coalition key | Plain EC sum of the signers’ public keys; the effective public key for the aggregate signature. |
| Commitment | Ethereum-style address (low 160 bits) of the Schnorr nonce point R. |
| PoP | Proof-of-Possession; a Schnorr signature proving control of a node key at registration. Molpha’s sole rogue-key defense. |
| Plan / Subscription | USDC tier definition / a consumer’s active monthly subscription on Solana; required to maintain feeds, not to read feeds. |
| Delegate | Hot agent authority under a subscription (["molpha_delegate", owner, delegate]) with request and quorum caps. |
| x402 escrow | Pay-per-request agent path: HTTP 402 funding loop plus on-chain AgentEscrow ATA settled by settle_agent_round. |
| AgentEscrow | Solana PDA + USDC ATA for x402 agent rounds (["molpha_agent", authority, gateway]). Not a separate access model from x402. |
| Gateway | HTTP service that dispatches signing rounds, returns payloads, and handles agent payment/settlement routing. |
