The core Mining Protocol carries jobs and shares over channels. Optional Job Declaration and Template Distribution separate template construction from pool accounting. V2 changes neither Bitcoin consensus nor PPS, FPPS or PPLNS payouts.
Stratum V2 encompasses the Mining, Job Declaration and Template Distribution protocols. Mining is required; the other two are optional. The suite coordinates work, not ASIC ownership, Bitcoin validity rules or a pool’s obligation to pay. [Stratum V2 — Protocol Overview] [Stratum V2 — Mining Protocol] [Stratum V2 — Job Declaration Protocol] [Stratum V2 — Template Distribution Protocol]
Braiins published Stratum V2 in 2019 with other Bitcoin developers to address Stratum V1 limits: textual encoding, weak connection security, overhead and the usual unilateral construction of jobs by pools. Its open specification and implementations continue to evolve. [Stratum V2 specification repository] [Braiins — Past and future of mining protocols] [Bitcoin Optech — Stratum V2 topic]
Every message has a six-byte binary header containing extension_type, msg_type and msg_length. SetupConnection must come first and negotiates protocol, version and flags; SetupConnection.Success confirms the actual choices. A product label or unconfirmed flag is not a negotiated capability. [Stratum V2 — Protocol Overview] [Stratum V2 specification repository]
For remote links the specification requires a cryptographic session; its optional handshake uses Noise, followed by AEAD traffic for confidentiality and integrity. A client validates the server certificate against a pool authority public key. One protected hop proves neither safe firmware, correct accounting nor pool solvency. [Stratum V2 — Protocol Security] [Noise Protocol Framework]
OpenStandardMiningChannel creates a simple header-only channel; OpenExtendedMiningChannel lets a proxy split extranonce and work space among downstream devices. A Group Channel can share jobs. Servers must allocate unique search space or ASICs waste energy hashing duplicate work. [Stratum V2 — Mining Protocol]
NewMiningJob or NewExtendedMiningJob describes work and SetNewPrevHash activates a previous hash; SetTarget assigns the pool target. SubmitSharesStandard or SubmitSharesExtended carries sequence_number, job_id, nonce, nTime and version. A share measures work; a block must meet Bitcoin’s network target. [Stratum V2 — Mining Protocol]
A proxy can aggregate many devices into an extended upstream channel and convert their standard work. A Translation Proxy lets Stratum V1 ASICs use V2 toward a pool, but the downstream hop remains V1 and the device gains neither native V2, end-to-end Noise nor automatic Job Declaration. [Stratum Reference Implementation libraries] [Braiins — Past and future of mining protocols]
Template Distribution connects a Template Provider, usually a Bitcoin Core full node, to a pool or Job Declarator Client. NewTemplate and SetNewPrevHash push current or future templates without getblocktemplate polling; RequestTransactionData supplies transactions and SubmitSolution returns a found block for propagation. [Stratum V2 — Protocol Overview] [Stratum V2 — Template Distribution Protocol]
A Job Declarator Client requests a token with AllocateMiningJobToken, sends DeclareMiningJob and possibly ProvideMissingTransactions, then supplies SetCustomMiningJob to the pool after acknowledgement. Only a pool accepting this flow enables custom templates; it may inspect, rate-limit or reject them. [Stratum V2 — Protocol Overview] [Stratum V2 — Job Declaration Protocol]
For any V2 offering, identify the exact subprotocols, roles, channel types, flags and implementation version; separately verify the authority key, endpoint, failover and error behavior. Monitor latency, rejected and stale shares, and logs. A V2 label, open channel or translator alone proves no transaction choice. [Stratum V2 specification repository] [Stratum Reference Implementation libraries] [Galaxy Research — Future of Bitcoin mining protocols]
For the clearest picture, read this entry together with Bitcoin, Mining, Mining Pool, Braiins, Braiins Pool, ASIC Miner. The reverse links also lead from Mining Pool, Braiins, Braiins Pool, Stratum V1.