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name: bitcoin-mining-stratum-v2 description: | Stratum V2: encrypted, miner-driven mining protocol. Job Declaration, Template Provider, allows miners to choose their own tx set. Defeats pool-level censorship. USE WHEN: deploying SV2-capable mining infrastructure, evaluating V1 vs V2, integrating with Braiins Pool / Datum. allowed-tools: Read, Grep, Glob

Stratum V2

Modern protocol replacing Stratum V1. Designed by Braiins (Slush Pool maintainers).

Spec: https://stratumprotocol.org/specification/.

Key improvements over V1

Aspect	V1	V2
Encryption	None	Noise XK (per-message AEAD)
Authentication	Username string	Cryptographic identity
Coinbase control	Pool only	Miner choice (Job Declarator)
Tx selection	Pool only	Miner can construct own block
Bandwidth	Verbose JSON	Binary (compact)
Multiple sub-protocols	No	Mining + Job Declaration + Template Provider + Job Negotiation

Architecture

Multi-role:

• Mining Protocol: ASIC ↔ pool/proxy.
• Job Declaration: miner declares their preferred block content.
• Template Provider: external service builds block templates from mempool (e.g., user's own bitcoind).
• Job Negotiation: pool and miner negotiate work assignment.

A miner running a Template Provider locally can:

1. Build their own block template from their own bitcoind mempool.
2. Submit hash work for that template via Job Declaration to pool.
3. Pool verifies + accepts.
4. Miner finds block, gets reward.

This decentralizes tx selection: miners — not pools — choose which txs to mine.

Encryption

Noise XK handshake → ChaCha20-Poly1305 per message. Modern crypto; defeats MITM and on-path analysis.

Channels

• Standard channel: per-miner, simple.
• Extended channel: pool-controlled, used for proxies.
• Group channel: bundled connections.
• Job Negotiator channel: separate negotiation.

Status (September 2026)

• Reference impl: SRI (Stratum Reference Implementation), Rust. Protocol crates in stratum-mining/stratum (v1.11.1, July 2026); the role applications — pool, jd-server, jd-client, translator — moved to stratum-mining/sv2-apps (v0.7.0, July 2026, alpha).
• Production pools: Braiins Pool and DMND run SV2 as full pools; CKPool, Blitzpool, MKPool, NexusPool, Public Pool and PyBlock run it as solo pools (stratumprotocol.org adoption list, September 2026).
• First miner-built template in production: DMND mined block 955,318 on 25 June 2026 with the template constructed by the miner (GoMining) via Job Declaration, not by the pool.
• Adoption: still a minority of hashrate, but on 7 May 2026 ANTPOOL, Block Inc., DMND, F2Pool, Foundry, MARA Foundation and SpiderPool joined the Stratum V2 Working Group.
• ASIC support: native SV2 firmware on Auradine (FluxOS), Braiins OS+, Bitaxe and NerdAxe; Mujina and Block's Proto still in progress (September 2026).
• Datum by Ocean Mining: SV2-compatible, decentralized template provider.

Use cases

• Censorship-resistant mining: miners choose own tx set.
• Independent miners: solo or small farms running their own bitcoind.
• Pool diversity: more easily switching pools.

Limitations

• Adoption lag — pool + ASIC + firmware all need to support.
• Complexity — multi-role architecture vs V1's simplicity.
• Backwards compat — many ASICs don't support yet.

Implementations

• Stratum Reference Implementation (SRI) — github.com/stratum-mining/.
• sv2-tp — the Template Provider, a standalone binary (github.com/stratum-mining/sv2-tp, v1.1.1, July 2026). It is not a Bitcoin Core feature: Core exposes a Cap'n Proto Mining IPC socket (bitcoin -m node -ipcbind=unix, Core 31.0+) that sv2-tp attaches to.
• Braiins OS+ — firmware with V2 support for some Antminer models.
• Ocean Mining Datum — V2-style decentralized template.

See also

• stratum-v1/SKILL.md
• decentralized-pools/SKILL.md
• firmware/SKILL.md