Stratum V1 vs V2 Support Matrix: Pools & Firmware

Stratum V1 is the original Bitcoin mining pool protocol: JSON-RPC over TCP, plain text by default, pools always build the block template. Stratum V2 is the next-generation replacement, documented in the Stratum V2 specification: binary framing (roughly 70% bandwidth reduction), mandatory Noise Protocol encryption (no unencrypted connections), and an optional Job Declaration sub-protocol that lets miners select their own transactions instead of accepting whatever the pool constructs. V2 is also faster — the specification targets job delivery in under 2.5 ms versus ~228 ms in V1. See our Stratum V2 guide for the full technical breakdown.

As of August 2026, three pools run V2 natively: Braiins Pool (pioneer, since ~2020, with full Job Declaration), DEMAND Pool (DMND) (first V2-native pool, public since November 2025, also with Job Declaration), and ckpool — including solo ckpool — whose source gained Stratum V2 on 31 July 2026, behind a HAVE_SV2 build flag. OCEAN Pool is not V2 but achieves equivalent decentralisation via DATUM. Foundry USA, AntPool, F2Pool, and MARA Pool all joined the Stratum V2 Working Group in May 2026 and are in testing or planning phases. Verify current status at each pool’s official documentation before switching.

BraiinsOS+ is the only major Antminer firmware with a native Stratum V2 client as of June 2026. Built by Braiins — the same team that developed and open-sourced the V2 specification, and the credit for V2 is theirs — it allows Antminer S9, S19 family, S21, and S21 XP miners to connect directly to V2 pools without a proxy. On open-source hardware, the Bitaxe’s AxeOS / ESP-Miner has shipped a native Stratum V2 client since v2.14.0 (June 2026), built by the open-source Bitaxe community — a current Bitaxe talks V2 to a V2 pool with no proxy. Those two are the production firmwares with native V2 today; stock Antminer, stock WhatsMiner, VNish and LuxOS remain V1 only (DCENT_OS implements a native V2 stack, but it is default-off behind a readiness gate and is not enabled in the July Antminer artifacts unless exact release notes say otherwise). Miners on V1 firmware can reach V2 pools by running the open-source SRI Translation Proxy locally. See our firmware comparison for the full feature matrix.

Template negotiation — formalized as the Job Declaration Protocol (JD) in the Stratum V2 specification — allows miners to build their own block templates and propose them to the pool instead of accepting whatever the pool assembles. This matters because it moves transaction selection power from pools to miners: even if a pool wanted to censor specific transactions, miners using Job Declaration can include those transactions themselves. The pool still validates work and handles payouts, but it cannot dictate which transactions enter the block. This is the core decentralisation upgrade that makes V2 more than just a performance improvement over V1.

DATUM is OCEAN Pool’s independent mining protocol, built from scratch with decentralisation as the primary design goal. The key technical difference: ASIC hardware still connects to a local DATUM Gateway via standard Stratum V1 (with BIP 310 version rolling). The gateway runs on the miner’s own machine, fetches block templates from the miner’s own Bitcoin full node, and relays only share-accounting data to OCEAN — the pool never sees the transaction list. OCEAN is cryptographically blind to what is in the block template. Stratum V2 with Job Declaration is conceptually similar but uses a different protocol stack and allows the pool to optionally audit the template before accepting it. Running DATUM requires a local Bitcoin full node (not optional). See the OCEAN guide for setup instructions.

Yes, with one additional step. The open-source SRI Translation Proxy (Stratum V2 Reference Implementation, funded by OpenSats) acts as a bridge: your ASIC connects to the proxy via standard V1, and the proxy speaks V2 to the pool. You run the proxy on a local machine (a Raspberry Pi works). The SRI proxy also supports the Job Negotiator role, so you can get transaction-selection capability even with stock V1 firmware. SRI v1.0.0 was released March 2024; v1.1.0 in October 2024. Source: github.com/stratum-mining/stratum. Credit: open-source contributor community and OpenSats.

Version rolling (BIP 310, also known as overt ASICBoost) allows miners to toggle specific bits in the Bitcoin block header version field, effectively multiplying the nonce search space by up to 65,536x without changing the actual block content. The pool and miner negotiate which bits are available via the mining.configure message with version-rolling.mask. The standard mask is 0x1FFFE000 (bits 13–28). Every firmware and pool in this matrix supports BIP 310 version rolling in production — it is universal as of June 2026. The Bible notes the default mask gives 2^16 × 2^32 = 2^48 total hash attempts per job without incrementing the extranonce. See the field manual for implementation details.

Yes, in source, since 31 July 2026. Commit 133709faf67f70a68219539c361bfff29c207e45 in ckpool’s canonical repository is titled “Stratum V2 support for ckpool, solo ckpool, and V1->V2 support for ckproxy, including JD.” Version 1.2.0 (28 July 2026) was tagged as the last minor release before SV2, and follow-up commits through 8 August 2026 tidy the HAVE_SV2 build guards and fix SV2 difficulty handling. So three things are now true that were not true in June 2026: ckpool speaks V2, solo ckpool speaks V2, and ckproxy translates V1 to V2 including Job Declaration — which is a second, independent route for a V1-firmware miner to reach a V2 pool alongside the SRI Translation Proxy. Two caveats, both material. SV2 is compiled in behind a HAVE_SV2 flag, so a given build may not have it. And a merged commit is not a deployed pool: we have not confirmed that the public stratum.ckpool.org endpoint runs a V2 build, and an open TCP port is not a protocol identification, so we grade that endpoint Unknown. ckpool is written by Con Kolivas. Source: bitbucket.org/ckolivas/ckpool.

DCENT_OS is D-Central’s open-source GPL-3.0 mining firmware. The V2 client exists in source behind a default-off readiness gate, but submit/accept soak remains pending and the July Antminer artifacts should be treated as V1-only unless exact release notes say otherwise. Signed experimental artifacts have been downloadable since 9 July 2026. No mandatory dev fee; the configurable donation ships at 2% on by default and can be set to zero. DATUM protocol support is also on the roadmap. Learn more at the DCENT_OS product page.