Constants & limits

Reading this reference

This chapter consolidates defaults and protocol limits that are otherwise distributed through source modules. Classify each value before changing it:

• consensus: changing it can make nodes disagree on valid history;
• wire: changing it breaks P2P byte compatibility;
• network identity: changing it creates or collides with a namespace;
• storage/API/client policy: local compatibility or operational behavior, not block validity;
• default: may be overridden without changing the protocol.

When a table and source differ, source and executable tests win until documentation is corrected.

Version matrix

Item	Value	Class
Python package	0.1.0	release
Python runtime	>=3.10,<3.13	build/runtime
wallet/site Node runtime	>=22.22.2	build/runtime
block version	1	consensus
transaction format	v1, no encoded version field	consensus
P2P protocol version	2	wire
private RPC API version	1	local API
Explorer API version	1	public API
explorer index schema	1	storage
block-location format version	1	storage
wallet vault version	1	client storage

Network identities

Network	Chain ID	Magic	Redis default DB	Explorer port	RPC port	Genesis
mainnet	0	ba77d89f	0	8000	8444	undefined; startup blocked
testnet	1	fbc0b6db	1	18000	18444	built-in educational manifest
devnet	2	faceb00c	2	28000	28444	built-in educational manifest

The default selected network is testnet. Default data path is:

~/.luracoin/<network>

LURACOIN_HOME changes the root; LURACOIN_DATA_DIR sets the exact directory.

Known genesis values

Network	Allocation	Nonce	ID
testnet	100,000 LURA	14,121,310	0000009e2bcc8e56cee8b5e0fbdac9edc04513542af5c5791ea6165179c468bf
devnet	100,000 LURA	11,943,016	00000033e4111007fd85423c7a527595e8efefe158a1250db62a32870857ef91

These identify disposable alpha chains.

Money and integer domains

Field/unit	Domain/value	Class
lurashis per LURA	100,000,000	consensus/UI
account balance	uint64	consensus
transaction value	1–2^64 - 1	consensus
transaction fee	uint32	consensus
transaction nonce	uint32	consensus
chain ID in transaction	uint8	consensus
block height	uint32	consensus
block PoW nonce	uint32	consensus
transaction count	uint16, at least 1	consensus
JSON monetary representation	decimal string	API

Arithmetic is integer-only and checked. Overflow is invalid, not wrapping behavior.

Address and key constants

Item	Value
elliptic curve	secp256k1
private key	32 bytes, valid scalar
compressed public key	33 bytes
raw transaction public key	64 bytes `x
address version	0x30
address payload	version + HASH160(compressed key), 21 bytes
checksum	first 4 bytes of double-SHA256(payload)
encoded address length	34 ASCII Base58Check characters
mnemonic entropy	256 bits
mnemonic words	24, English list
BIP39 passphrase	LURA
BIP32 path	master/root key; no child derivation path
zero address sentinel	34 ASCII 0 characters

The zero sentinel is not a valid Base58Check destination. It is reserved as coinbase origin.

Transaction sizes and offsets

Offset	Size	Field
0	1	chain
1	4	nonce, little-endian
5	4	fee, little-endian
9	8	value, little-endian
17	34	sender ASCII
51	34	recipient ASCII
85	64	raw public key
149	64	compact signature

unsigned bytes          85
unlock field           128
complete transaction   213
complete transaction hex characters 426

Signing digest is one SHA-256 of the unsigned 85 bytes. Transaction ID is double-SHA256 of all 213 bytes. Signature is deterministic RFC 6979 compact r || s with low-S enforced.

Block constants

Item	Value
transmitted header	118 bytes
block version	1
declared ID	32 bytes
predecessor	32 bytes
miner	34 ASCII bytes
timestamp encoding	4-byte big-endian Unix seconds
bits	4 bytes
nonce	4-byte little-endian
hash-preimage transaction count	2-byte little-endian
maximum transactions	65,535 including coinbase
coinbase maturity in implementation constant	1
maximum future timestamp	500 seconds

The coinbase is credited after normal transaction evaluation, so current-block subsidy is not spendable in its own block.

Block-size schedule

Height from	Bytes maximum
0	10,000
28,800	50,000
57,600	75,000
86,400	200,000
172,800	1,000,000
259,200	2,000,000
345,600	3,000,000
432,000	8,000,000

Serialized size is 118 + 213 × transaction_count.

PoW and economics

Item	Value	Class
starting compact bits	1dffffff	consensus
maximum compact target basis	1fffffff	consensus
target block interval	180 seconds	consensus
difficulty interval	480 blocks	consensus
expected retarget span	86,400 seconds	consensus
adjustment clamp	¼× to 4× time span	consensus
starting recurring subsidy	50 LURA	consensus
halving interval	259,200 blocks	consensus
tail subsidy floor	1 LURA forever	consensus

There is no finite maximum supply under permanent tail emission.

P2P framing and limits

Item	Value
default bind host	0.0.0.0
default P2P port	9999
message header	24 bytes
command field	12 bytes
checksum	first 4 bytes of payload double-SHA256
max block payload	8,000,000 bytes
max global P2P payload	8,000,004 bytes
v2 VERSION payload	18 bytes
peers maximum in payload	256 IPv4 endpoints
sync batch	50 blocks
total peers default	8
inbound peers default	8
ping interval	60 seconds
pong wait	10 seconds
send timeout	5 seconds
known inventory cache	50,000 hashes

Exact command payload sizes are listed in P2P v2 wire protocol.

Synchronization and relay defaults

Item	Default	Environment
sync cooldown base	30 seconds	LURACOIN_SYNC_COOLDOWN_BASE
sync cooldown maximum	900 seconds	LURACOIN_SYNC_COOLDOWN_MAX
stored host histories	4,096	LURACOIN_SYNC_COOLDOWN_LIMIT
pending relay backlog	1,000	LURACOIN_PENDING_RELAY_LIMIT
replay batch per peer	100	LURACOIN_REPLAY_BATCH_SIZE
replay budget per peer	5 seconds	LURACOIN_REPLAY_BUDGET_SECONDS
peer maintenance interval	30 seconds	internal default
per-block sync wait	30 seconds	internal default

These are node policy/DoS bounds, not consensus fields.

Canonical storage

Item	Value
block record prefix	4-byte little-endian serialized length
block file rotation	134,217,728 bytes (128 MiB)
block filename	blkNNNNNN.dat
location entry	17 bytes
location version	1
location file number	4-byte little-endian
location offset	8-byte little-endian
location expected length	4-byte little-endian
account DB	accounts.db
block/index DB	blocks.db
chain metadata DB	chainstate.db
optional explorer DB	explorer.sqlite3

Redis defaults

Item	Value
host	localhost
port	6379
mainnet/testnet/devnet DB	0 / 1 / 2
tests DB	9
payload key	64-hex transaction ID
nonce key	nonce:<chain>:<sender>:<nonce>

Override with LURACOIN_REDIS_HOST, LURACOIN_REDIS_PORT, and LURACOIN_REDIS_DB.

Private RPC limits

Item	Value
bind	loopback only
ports	8444 / 18444 / 28444 by network
token path	<data-dir>/rpc.token
token minimum	32 characters
desired token mode	0600
maximum token file	4,096 bytes
maximum request body	1,000,000 bytes
history page limit	1–200; default 50
canonical submit bytes	213
successful submit status	202

The official Electron RPC client adds an 8-second request timeout and 2,000,000-byte response cap.

Browser-wallet gateway limits

Item	Value
default host	127.0.0.1
default port	8080
request body	16 KiB
proxied RPC response	2,000,000 bytes
static file maximum	16 MiB
upstream timeout	5 seconds
cookie name	luracoin_wallet_session
API prefix	/wallet-api

Allowed bind hosts are 127.0.0.1 and 0.0.0.0; the latter is intended only for a container published back to host loopback.

Explorer API limits

Item	Value
API prefix	/api/v1
default page size	25
maximum normal page	100
default/max block page	10 / 10
maximum offset	2,147,483,647
default bind	127.0.0.1
ports	8000 / 18000 / 28000
index enabled	false by default
index polling base	2 seconds
index retry maximum	60 seconds
CORS methods	GET
CORS origins	*, credentials false
CORS max age	600 seconds

Official wallet constants

Item	Value
wallet storage key	luracoin.wallet.v1
preferences key	luracoin.preferences.v1
vault KDF	PBKDF2-HMAC-SHA256
default KDF iterations	250,000
accepted stored KDF range	100,000–5,000,000
salt	16 random bytes
cipher	AES-256-GCM
IV	12 random bytes
default auto-lock	5 minutes
selectable auto-lock	0, 1, 5, 15 minutes
default/only live network	testnet
live refresh interval	15 seconds
history request limit	100 per page
UI history bound	5 pages / 500 entries
official transaction fee	0 lurashis in current UI
pending outgoing policy	one at a time in current UI
wallet-name maximum	60 characters

Client policy can change without changing consensus, but any signing/encoding change must remain byte-compatible.

Configuration precedence

For node commands:

explicit CLI option > environment-derived Config default > built-in default

The CLI does not load .env automatically. Use exported environment variables or a service manager. Keep each network’s data directory, Redis DB, service ports, and peers explicit when running multiple instances.