Adding a chain: the checklist

For whoever adds the next coin, person or agent. Most of a chain is data, its Params in arcade/config.py: the launcher flags, core: / share:, mesh Core peering, borrowing, discovery, fees, dust and the ord index all follow from them. This page lists what still needs a hand, learned from adding Bellscoin and Luckycoin (2026-10-22). Use Dogecoin (doge), Bellscoin (bel) and Luckycoin (lky) as the worked examples.

From its chainparams.cpp and chainparamsbase.cpp:

• genesis hash
• base58 versions: P2PKH, P2SH and WIF
• bech32 HRP, and whether SegWit or Taproot are active
• RPC and P2P ports
• AuxPoW chain id and start height, and how the header holds the id
• From policy.h and validation.h: the minimum relay fee, dust, soft dust, the OP_RETURN size (80 bytes must be standard) and bare multisig (must relay)

Then check every value against a node of that chain:

• getblockhash 0
• validateaddress on an address of each kind
• signmessagewithprivkey with a throwaway key in its WIF

Copy the nearest relative: DOGECOIN for a Dogecoin-code chain, LITECOIN for a Bitcoin-Core-based one. Set:

• name, coin, label
• the ports, the versions, genesis
• auxpow_chain_id, and auxpow_chain_mask when the chain keeps versionbits beside its id
• min_fee_per_kb, soft_dust, dust_limit
• letter (one not already used for a badge), family, net_word
• node_dir, node_conf
• real_coins, bech32_hrp

Add it to NETWORKS and CHAIN_NAMES. Set the floor at the tip rounded up about two days (D-004). The other arcade must take the same floor. Mainnets keep swaps, takes and the rest at None.

config.unpayable_versions finds a P2SH byte that is another chain's P2PKH byte. Bellscoin's 30 is Dogecoin's "D", and txbuild reads a version byte the same on every chain. Such a chain:

• refuses that payee (_check_address)
• makes no arcade lock there (require_p2sh_payable)

The inscription guard watches a script byte only where no other chain uses it. Look for the quieter clashes too: Luckycoin's P2SH 5 is Litecoin's legacy "3".

• coins.js: COIN_TYPE (3 for a real-coin chain, 1 for a test chain), WIF, WIF_CHAIN.
• wallet_js.js: TRADE.BIG, CLAIM_FEE, FEE_FLOOR, PAYEE_VERSIONS, P2SH_VERSION, COIN_WORD, REAL_COINS. tests/test_trade_fees.py holds the fee tables to Python's.
• trade.py: BIG. Set it low until the operator sets swap_big:<net>.
• txbuild.py: SCRIPTHASH_VERSIONS, only for a byte that clashes with nothing.
• doginal_index.py: STARTS (the official indexer's first_inscription_height, or the first envelope found by scanning the chain), SOURCES, TAPROOT.
• ord_rules.py: RULES_BY_NET and NUMBERS_REINSCRIPTIONS. Follow the chain's official indexer, and bump the chain's rules when its numbering changes so its indexes are cut again.
• Templates:
• my_wallet.html: ORD_WORDS and the inscription word.
• my_backup.html: the key list.
• _tab_swaps.html: the coin names.
• base.html: the real-coin review card.
• base_css.css: the chain's colours and tags.
• coin-<net>.png: its icon.
• This docs page list: arcade/web/guide.py ORDER, and a page of its own like this one's neighbours.

• Tests:
• a test file like tests/test_bells_luckycoin.py: Params, titles, address refusals, twins, the guard, tiers, the browser tables and the Admin opt-ins
• real blocks for rawchain (read, work, Core's own decoding)
• the ord dialect tests
• The whole suite, compared with main on the same machine.
• A scratch walk of its ord index against its own node. Then compare numbers and blocks with the chain's public index: #0, the newest, and a random spread. A drift finds its first differing number by bisection. That is how Bellscoin's reinscription rule was found.