Scope

Full block-producing node for Shelley+ eras using Ouroboros Praos.

Capabilities

• Leadership test per slot (VRF) with correct nonce handling; KES hot-key rotation; op-cert validation.
• Mempool: bounded queue, policy, rebase on adoption; fee/min-ADA/ttl enforcement pre-admission.
• Block assembly: select txs, respect per-block limits (size, exec units), compute body hash, sign header.
• Pipelined diffusion on send; polite propagation and backpressure integration.
• Ops hardening: key isolation, HSM/TPM optional, sealed configs, audit logging, failover pairs.

Non-goals

• Legacy Byron/Shelley production; experimental consensus.

Done when

• Produces valid blocks on preprod/preview with stable metrics and no safety violations.
• Missed-slot and orphan rates within target; propagation latency competitive with reference.
• Key lifecycle (KES rotation, op-cert renewal) passes operational runbooks and chaos tests.