Configuration

What can be configured, where, and the devnet’s values. Command-line flags are in the command-line reference.

Environment variables

Variable	Used by	Default	Meaning
`SION_NODE`	every command (`--node`)	`http://127.0.0.1:8730`	The node’s HTTP API
`SION_HOME`	wallet commands	`~/.sion` (`$HOME/.sion`)	Named wallets’ seeds live in `$SION_HOME/wallets/<name>.seed`
`SION_CHAIN`	`sion verify`, `sion receipt`, `sion x402 serve`, `sion x402 fetch` (`--chain`)	none	The chain identity you trust. Without it, the node vouches for itself

Set SION_CHAIN once per shell to pin the devnet you use:

export SION_CHAIN=<identity printed by sion devnet>

Devnet (`DevnetConfig`)

sion devnet builds a sion_node::DevnetConfig from its flags. Fields without a flag keep their default; Rust code that starts a devnet (sion_node::Devnet::start) can set them all.

Field	Default	Flag	Meaning
`chain_id`	`sion-devnet-1`	none	The chain’s name; devnet keys derive from it
`validators`	4	`--validators`	Validators in the genesis active set
`standby`	0	`--standby`	Validators that run from the start without a seat and join by staking
`validator_stake`	100,000 USD	none	Each genesis validator’s stake
`min_stake`	10,000 USD	none	The least stake a validator may register with
`epoch_length`	0	`--epoch-length`	Pulses per epoch; 0 means one epoch that never ends
`unbonding`	20	`--unbonding`	Pulses between leaving the active set and withdrawing stake
`shards`	2	`--shards`	Lane shards
`shard_seats`	4	`--seats`	Seats per lane committee, capped at the active set’s size
`rounds_per_pulse`	4	`--rounds-per-pulse`	Consensus rounds per Pulse
`batch_interval_ms`	25	none	How often validators sign a batch of lane approvals
`signatures`	dual post-quantum	`--insecure-fast-signatures`	Validator signatures; the flag selects an insecure simulation MAC
`data_dir`	none (memory only)	`--data-dir`	Where validators keep logs, snapshots and epoch proofs
`snapshot_every`	50	none	Pulses between snapshots
`fsync`	false	none	Whether to fsync every log record
`demo_accounts`	`alice`, `bob`, `carol`	`--accounts`	Named devnet wallets funded at genesis
`demo_usd`	100,000	none	USD each named account starts with, as four equal coins
`accounts`	none	none	Extra genesis accounts
`core`	see below	none	Consensus parameters
`prove_chunk`	16	`--chunk`, `--no-prove`	Transactions per proof chunk; `--no-prove` disables proving
`history`	256	none	Pulses of outputs, data and traces kept in memory
`forced_window`	8	`--forced-window`	Pulses a shard has to execute a forced intent

The genesis also funds a faucet account with 1,000,000,000 USD.

Chain (`ChainConfig`)

Part of the genesis; its digest is in every world commitment, and transaction signatures cover it.

Field	Devnet value	Meaning
`chain_id`	`sion-devnet-1`	The chain’s name
`shard_count`	2	Lane shards
`base_fee`	0.001 USD	Fee per transaction
`fee_per_kib`	0.0001 USD	Fee per started KiB of the body (signatures excluded)
`faucet`	the `faucet` account	Who may send `Faucet` transactions (none on a production chain)
`max_claim_window`	1,000,000 Pulses	The longest validity a claim may ask for
`max_formula_size`	256	The most nodes in a claim’s formula, before claim references are unfolded
`max_payload_bytes`	64 KiB	The largest claim payload
`challenger_share_permille`	500	The successful challenger’s share of a released slashing pool, in thousandths; the rest goes to the treasury

Validator set (`ValidatorParams`)

Fixed at genesis, held in the validator set object. See Validators, staking and epochs.

Field	Devnet value	Meaning
`stake_asset`	USD	The asset validators stake
`epoch_length`	`--epoch-length`, or 2⁶³ − 1 for 0	Pulses per epoch
`min_stake`	10,000 USD	The least stake to register
`unbonding`	`--unbonding` (20)	Pulses from exit to withdrawal
`seats`	`--seats` (4)	Seats per lane committee
`max_active`	100	The most validators in the active set
`reward_permille`	700	Share of each epoch’s fees paid to that epoch’s validators
`reporter_permille`	50	Share of a slashed stake paid to the reporter

Forced inclusion (`ForcedParams`)

Field	Devnet value	Meaning
`window`	`--forced-window` (8)	Pulses a shard has to execute a posted intent
`max_pending`	4,096	The most obligations pending at once; later intents are dismissed

Consensus (`CoreConfig`)

Field	Devnet value	Meaning
`leader_timeout_ms`	400	How long to wait for an anchor or its votes before advancing
`resend_interval_ms`	600	How often to re-broadcast and re-request missing parents
`gc_depth`	50	Rounds of history kept below the last committed anchor
`max_items_per_header`	2,000	Payload items per header
`max_payload_bytes`	512 KiB	Payload bytes per header
`max_rounds_ahead`	64	Headers for rounds further ahead are ignored
`max_pending_headers`	4,096	Headers waiting for parents
`repropose_after_rounds`	8	Re-propose an item not delivered after this many rounds
`leader_schedule`	`RoundRobin`	Anchors in committee order

Fixed limits

Limit	Value	Where
Inputs per transaction	1 to 256	`sion_exec::tx::MAX_INPUTS`
Allotments per bounded total	256	`sion_exec::escrow::MAX_ALLOTMENTS`
Orders per market batch	1,024	`sion_exec::market::MAX_BATCH_ORDERS`
Formula nesting at issuance	32	`sion_assurance::registry::MAX_FORMULA_DEPTH`
Formula nesting when decoding	64	`sion_assurance::formula::MAX_DECODE_DEPTH`
Chain of claim references	16	`sion_assurance::registry::MAX_CLAIM_DEPTH`
Charters read by a chain check	16	specification §5.13
Transaction validity set by the CLI	20 Pulses	wallet default
Lane requests parked for a lagging validator	up to 4 Pulses	lane validator
Beacon hash chain per devnet validator	2¹⁷ Pulses	`sion_node::devnet::BEACON_CHAIN_LENGTH`
Devnet faucet grant through the API	1 micro-unit to 1,000,000 units	`POST /v1/faucet`
Faucet grant in a transaction	at most 1,000,000,000 units	`sion_exec::tx::MAX_GRANT`

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