Technical reference
Chain identity and integration data
Production reference for Bitcoin BIP110 chain identity, node software, network parameters, BLAKE2b proof of work, logo assets, replay protection, custody, and exchange integration.
Chain identity
Fork anchors are the network discriminator
Bitcoin BIP110 shares Bitcoin's genesis block, mainnet network magic, default ports, and address encodings. Services must identify the chain using the fork-anchor hashes below rather than address appearance or chain=main.
| Checkpoint | Height | Expected hash |
|---|---|---|
| Last common block | 961,631 | 00000000000000000000807f9dc917442a67910426d79ebb2f8aa2149327ce8a |
| First Bitcoin BIP110 branch block | 961,632 | 0000000000000000000169eb6f811ddbd0daf343af7b62180cdb13e7c78dbc16 |
| Final SHA-256d block | 961,639 | 00000000000000000001bbc439e13f749dca850d32c7a2834165338713027e65 |
| First BLAKE2b block | 961,640 | 0000000000000050c1e5f69672f459293be14f46e5a494e7a8c8541396f18eeb |
Mandatory identity rule: a checkpoint mismatch should disable deposit crediting and withdrawal broadcast.
Exchange and custody integration
Production fact sheet
These are the project-declared and operational values intended for exchange, wallet, custodian, explorer, and infrastructure integration.
- Preferred listing name
- Bitcoin BIP110
- Project-declared ticker
- BIP110
- Date of issue (chain split)
- 8 August 2026
- Max Supply (nominal)
- 21,000,000 BIP110
- Circulating supply at issuance (nominal)
- 20,067,600 BIP110
- Website
- https://bitcoinbip110.org/
- Asset type
- Native UTXO coin
- Decimal places
- 8
- Base units per coin
- 100,000,000
- Reference implementation
- Bitcoin Knots
- Recommended release
29.4.1.knots20260508/v29.4.1.knots20260508- Release directory
- bitcoinknots.org/files/29.x/29.4.1.knots20260508/
- Block explorer
- https://mempool.guide/
- Explorer transaction template
https://mempool.guide/tx/{txid}- Explorer address template
https://mempool.guide/address/{address}- Circulating supply URL
- No dedicated circulating-supply endpoint is currently published.
- RPC chain name
main(not unique to Bitcoin BIP110)- P2P message start
f9 be b4 d9- Default P2P port
8333- Default RPC port
8332- P2PKH / P2SH
0x00/0x05- Bech32 HRP
bc- BIP32 public / private prefix
0488b21e/0488ade4
Issue and supply basis: the date of issue is the date of the first Bitcoin BIP110 branch block at height 961,632. The 20,067,600 BIP110 figure is the nominal subsidy-derived supply through the last common height 961,631 and does not subtract lost, burned, or otherwise provably unspendable coins.
Consensus transition
BLAKE2b and version-2 headers
The Bitcoin BIP110 branch used SHA-256d through height 961,639 and permanently switched to BLAKE2b at height 961,640 on 30 August 2026.
| Property | Value |
|---|---|
| Proof of work through 961,639 | SHA-256d |
| Proof of work from 961,640 | BLAKE2b, permanent |
| Legacy header size | 80 bytes |
| Header size from 961,640 | 164 bytes, header generation 2 |
| Target spacing | 600 seconds |
| Legacy target timespan parameter | 1,209,600 seconds |
| Mainnet BLAKE2b target shift | 22 |
| Coinbase maturity | 100 blocks |
| Subsidy halving interval | 210,000 blocks |
| Next halving height | 1,050,000 |
| Nominal max supply | 21,000,000 BIP110 |
| Nominal issued supply at split | 20,067,600 BIP110 |
Raw-header consumers must support the version-2 fields exposed by the reference node, including txcount, header_version, nonce2, nonce3, extranonce, time_offset, header_flags, xor_key, xor_key_mask_clear_bits, and mm_rhs.
Temporary consensus window
Reduced-data rules
The temporary reduced-data window activates with BLAKE2b at height 961,640 and expires according to previous-block median time past at 1 September 2027 00:00 UTC. BLAKE2b remains active after expiry.
- Activation height
- 961,640
- Expiry clock
- Previous block median time past
- Expiry time
- 1 September 2027 00:00 UTC
- Temporary maximum block weight
- 800,000 weight units
- Approximate serialized size
- About 300 kB
Replay protection and custody
SIGHASH_UNIFIED is opt-in
Ordinary signatures spending shared pre-fork outputs can remain valid on both histories. SIGHASH_UNIFIED uses hash-type bit 0x20 and tagged hash UnifiedSighash to provide one-way replay protection for signatures that opt in.
| Property | Value |
|---|---|
| Opt-in granularity | Per signature |
| Covered script families | Bare/P2SH, SegWit v0, Taproot key path, Tapscript |
| Signer input data | Value and scriptPubKey of every spent output |
| Reference test vectors | 166 |
| Normal withdrawal inventory | Use BIP110_ONLY outputs; exclude SHARED and UNKNOWN |
BTC and BIP110 systems should use separate data directories, node processes, wallet databases, signer namespaces, deposit mappings, withdrawal queues, broadcast paths, and accounting asset IDs.
Production verification
Minimum RPC identity profile
Check the following. A service should fail closed if a mandatory checkpoint fails, the node reports initial block download, the wallet or indexer materially lags the node, RPC health fails, or the signer is unavailable.
bitcoin-cli getblockchaininfo
bitcoin-cli getdeploymentinfo
bitcoin-cli getblockhash 961632
bitcoin-cli getblockhash 961639
bitcoin-cli getblockhash 961640Integration package
Viewable specifications
The Markdown, PDF, and JSON files below carry the same production chain identity and integration values used by this page.