Home / Docs / System Constants System Constants Difficulty, timing, size limits, lease economics, performance certificates — and which of them are network parameters rather than binary constants.
Most values below are compiled into the xe binary. The lease timing block is not: it is set in the ledger genesis of each network and published by every node under GET /node → lease_timing, so the live network can differ from the defaults, and does.
DefaultDifficulty (blocks): 0xfffff80000000000
DefaultPoWDifficulty (chat envelopes): 0xffffc00000000000
TestDifficulty: 0x0000000000000002
Both live difficulties are advertised in GET /node (pow_difficulty, chat_pow_difficulty).
Constant Value Block timestamp tolerance ±1 hour Vote window ±5 minutes Re-vote backoff 15 seconds Chat envelope freshness ±5 minutes Chat read challenge TTL 120 seconds Attestation rate limit 15 seconds per lease per client Quorum fallback 10 seconds Lock stability window 3 seconds Stale conflict sweep 15 seconds Periodic sync 10 seconds Sync rate limit 5 seconds/peer Statechain sync rate limit 30 seconds/peer Bootstrap re-dial watchdog 30 seconds (10 s dial timeout) Ambient discovery round 60 seconds (5 min backoff, target 24 peers) Directory TTL 30 minutes (xe directory register --watch refreshes every 20) Wallet unlock 30 minutes, hard
Parameter Binary default testnet-0005 genesismin_duration_secs60 5 settle_grace_ns1 h 120 s force_settle_gap_ns25 min 300 s escrow_expiry_ns365 d 1 h archive_gap_ns1 h 10 min max_attestation_skew_ns10 min 60 s
Read them live: curl -s https://ldn.core.test.network/node | jq .lease_timing.
Limit Value Conflict hashes 10 max Pending votes/conflict 10 max Attestations/block 20 max Memo 64 bytes UTF-8 POST body 1 MiB Gossip message 256 KB Sync request 1 MiB Sync response 10 MiB Sync blocks/session 10,000 Sync page 64 default, 256 max Frontiers/request 10,000 State key 128 bytes State value 64 KB State block 256 KB Message request/response 64 KB Netcheck handshake 1 KB, ≤ 8 advertised features List pagination limit default 100, max 1,000
Parameter Value Min duration min_duration_secs (network parameter, 5 s on testnet-0005)Max duration 31,536,000 s (365 days), cumulative across renewals Max per lease 4,096 vCPUs, 67,108,864 MB memory, 1,048,576 GB disk Billing granularity 1 minute (duration rounded up to whole minutes) vCPU rate 20,000 µXUSD/hour Memory rate 10,000 µXUSD/GB/hour Disk rate 1,000 µXUSD/GB/hour Provider stake none (LeaseStakeDivisor = 0) XE emission ceil(cost × R_capped / 1000) µXE per segment (min 1, R locked at accept / each renewal) R fallback 2000 (2.000×) when no epoch is published
Parameter Value WorkloadVersion 4 PoWPuzzles 1,024 chained puzzles PoWDifficultyBits 19 MemoryTableSize 8,388,608 entries (256 MB) MemoryReads 10,000,000 CertificateValidity 7 days PriceMultiplierMilli 500 – 10,000, default 1,000
Parameter Value Quorum threshold 67% of delegated XE weight Fallback finalization strict majority (>50%) of lowest-hash final votes after 10 s Connection manager low 100 Connection manager high 400 Connection grace 1 minute Max inbound connections per IP 8 (--max-conns-per-ip) Max inbound connections 256 (--max-inbound-conns) Netcheck mismatch ban 10 minutes (network id), 1 hour (protocol version) API rate limit (reads, GET) 200 req/s, burst 1,000 API rate limit (writes, POST) 10 req/s, burst 50 API rate limit (probes, /health /ready) 20 req/s, burst 100 Rate limiter idle TTL 5 minutes (max 100,000 tracked IPs) Default API port 8080 (bind 127.0.0.1) Default UI port 8000 (bind 127.0.0.1) Default metrics/ops port 9095 (bind 127.0.0.1; /metrics, /health, /ready) Default libp2p port 9000 Readiness defaults ≥ 1 peer, sync within 180 s, finality stall ≤ 90 s
