Solana program reference

The Kiln program is written in Rust with the Anchor framework. This page lists everything a client needs to talk to it.

Constants

Name	Value	Meaning
HEARTBEAT_GRACE_SECS	180	Longest gap between heartbeats that still counts
MAX_LEASE_HOURS	2,160	Longest lease (90 days), including top-ups
MAX_FEE_BPS	2,000	Fee ceiling, 20%
MAX_HOST_LEN	128	Longest gateway URL a listing can publish

Addresses (PDAs)

Account	Seeds
Config	["config"]
Provider (listing)	["provider", owner, mint]
Lease	["lease", renter, nonce as u64 little-endian]
Escrow token account	["escrow", lease]

One owner can have one listing per payment mint.

Accounts

Config (75 bytes)

Field	Type
admin	Pubkey	Can change fee and treasury
treasury	Pubkey	Owner of the token accounts fees are paid to
fee_bps	u16	Protocol fee, basis points
bump	u8

Provider (307 bytes)

Field	Type
owner	Pubkey	Receives payouts, manages the listing
heartbeat_authority	Pubkey	Key that signs heartbeats
mint	Pubkey	Payment currency
price_per_hour	u64	For the whole listing, in base units
gpu_model	[u8; 32]	UTF-8, zero-padded
gpu_count	u8
region	[u8; 16]	UTF-8, zero-padded
active	bool	Accepting new leases
active_leases	u32	Open leases
total_verified_secs	u64	Lifetime proven time
bump	u8
host	String (≤ 128)	Gateway URL; kept last so the fields above have fixed offsets

Lease (176 bytes)

Field	Type
renter	Pubkey	offset 8 (useful for getProgramAccounts filters)
provider	Pubkey	offset 40
mint	Pubkey
nonce	u64	Chosen by the renter; part of the address
price_per_hour	u64	Fixed at opening
deposited	u64	Total funded
paid	u64	Total paid out (provider + fee)
start_ts, end_ts	i64	Unix seconds
last_heartbeat_ts	i64	0 until the first heartbeat
verified_secs	i64	Proven time
heartbeats	u32	Count
last_utilization_bps	u16	0–10,000
bump, escrow_bump	u8

Instructions

Instruction	Signer	Arguments	Effect
init_config	admin (once)	fee_bps, treasury	Creates Config
update_config	admin	fee_bps, treasury	Changes fee/treasury
register_provider	owner	heartbeat_authority, price_per_hour, gpu_model, gpu_count, region, host	Creates a listing
update_provider	owner	price_per_hour, active, heartbeat_authority, host	Edits a listing
open_lease	renter	nonce, hours	Creates lease + escrow, deposits price × hours
top_up	renter	hours	Adds funds and time at the lease's price
heartbeat	heartbeat authority	utilization_bps	Adds verified time (see proof of rental)
settle	anyone	—	Pays verified, unpaid time to owner and treasury
close_lease	renter or owner	—	Settles, refunds the rest, closes escrow and lease

Events

Event	Fields
ProviderRegistered	provider, owner, mint, price_per_hour
LeaseOpened	lease, renter, provider, deposited, end_ts
HeartbeatEvent	lease, provider, utilization_bps, verified_secs, ts
Settled	lease, amount
LeaseClosed	lease, paid_on_close, refunded

Errors

Code	Name	When
6000	FeeTooHigh	Fee above 20%
6001	ZeroPrice	Price is 0
6002	ZeroGpus	GPU count is 0
6003	BadHours	Hours outside 1–2,160, or top-up beyond the maximum
6004	ProviderInactive	Listing paused
6005	LeaseEnded	Top-up or heartbeat after the end
6006	BadUtilization	Utilisation above 10,000 bps
6007	Unauthorized	Wrong signer
6008	WrongMint	Token account or mint mismatch
6009	WrongProvider	Lease belongs to another listing
6010	MathOverflow	Arithmetic overflow
6011	BadHost	Gateway URL not http(s)://… or longer than 128 characters

Testing

Every build runs unit tests on the payout maths and end-to-end tests that load the compiled program into a local Solana VM. They cover full leases, outages, unauthorised heartbeats, over-long heartbeating, closing rights and listing updates.