Error codes

Look up a revert string here to find the contract that raises it and the condition behind it. Each table maps the revert strings of one contract to their causes. The tables cover the core, DAO, and net-pressure contracts of yb-core. They also cover the lending oracles YBLendingOracle, YBLendingOracleLL, and YBLendingOracleLLFactory, the Curve Twocrypto pools of markets 7 to 10, and the pool policies.

The four ERC-4626 cap strings share one row in the LiquidityGauge.vy and FastGauge.vy tables, written as erc4626: deposit/mint/withdraw/redeem more than maximum.

Some checks have no message and revert with empty data. For each contract that has them, a list after its table names the main ones.

A revert inside a Curve pool call reaches the caller of the YieldBasis function. For example, a pool policy revert inside add_liquidity reaches the caller of LT.deposit.

LT.deposit, LT.withdraw, and AMM.exchange end with the borrower-fee donation to the Curve pool. If that donation fails, the pool reverts with slippage or donation above cap!, and the whole call reverts. A VirtualPool route reverts in the same way, through AMM.exchange. For the donation, read distribute_borrower_fees in the LT contract reference.

Core

LT.vy

LT.vy reverts with these strings:

String	Cause
Access	Caller neither admin nor factory admin
Already set	Second set_amm
Slippage	min_shares / min_assets not met
Debt too high	LEVAMM value after the deposit would exceed AMM.max_debt() / 2 (preview_deposit also raises it)
Withdrawing nothing	withdraw(0)
Withdraw to/from staker	The gauge (staker) is msg.sender or receiver
We're dead. Use emergency_withdraw	Normal withdraw while the LEVAMM is killed
Remainder too small	Supply would drop below MIN_SHARE_REMAINDER (1e6)
Deposit to staker	receiver == staker in deposit
N>2	Constructor: the Curve pool has more than 2 coins (coins(2) did not revert)
receiver	emergency_withdraw from the emergency admin or the admin with receiver other than owner
owner	emergency_withdraw from any other caller with owner other than msg.sender
Not killed	A caller other than the position owner calls emergency_withdraw while the LEVAMM is live
Need factory	withdraw_admin_fees called when admin is not a factory contract
Killed	Admin-fee withdrawal while the LEVAMM is killed
No fee_receiver	Factory fee receiver is unset
Staker=fee_receiver	The fee receiver is the gauge (staker)
Loss made admin fee negative	Admin-fee withdrawal attempted while admin bucket is negative
Staker already set	Second set_staker
GAS	Gauge checkpoint retry path: _checkpoint_gauge falls back to a fixed-gas call (200k) and requires the caller to supply at least that much. This guards against gas-griefing of reward checkpoints

For the caller rules of emergency_withdraw, read emergency_withdraw() in the LT contract reference.

AMM.vy

AMM.vy, the LEVAMM contract, reverts with these strings:

String	Cause
Fee too high	Constructor: fee > MAX_FEE (10%)
Unsafe min	debt < coll_value · MIN_SAFE_DEBT / 1e18
Unsafe max	debt > coll_value · MAX_SAFE_DEBT / 1e18
Access	set_rate / set_fee / set_killed from non-LT
Access violation	_deposit / _withdraw from non-LT
Rate too high	rate > MAX_RATE (100% APR)
Amount too large	get_dy(i=0, in_amount > debt)
Slippage	exchange with out < min_out
Empty AMM	exchange with collateral_amount == 0
Bad final state	Post-swap x0 < x0_pre

This call reverts without a message:

• set_fee with fee > MAX_FEE, the same check as Fee too high.

VirtualPool.vy

VirtualPool.vy reverts with these strings:

String	Cause
Wrong caller	onFlashLoan not from FACTORY.flash()
Slippage	Output below min_out

These calls revert without a message:

• onFlashLoan with initiator != self or token != STABLECOIN.
• get_dy or exchange with (i, j) other than (0, 1) or (1, 0).

Factory.vy

Factory.vy reverts with these strings:

String	Cause
Access	Non-admin on admin function
Wrong stablecoin	Pool's coin 0 ≠ factory STABLECOIN
Only set once	set_mint_factory re-called
Minter	set_allocator targets mint_factory
Already set	set_gauge_controller re-called
Admin fee too high	min_admin_fee > 1e18
Bad aggregator	Init / set_agg with agg.price() ∉ (0.9e18, 1.1e18) (open interval, both ends)
Too many markets	market_count ≥ 50000
Nonexistent market	fill_staker_vpool(i ≥ market_count)

HybridVault.vy

HybridVault.vy reverts with these strings:

String	Cause
Already initialized	A second initialize call
Access	Generic non-owner caller on owner-only function (deposit, withdraw, emergency_withdraw, stake, unstake, redeem_crvusd, withdraw_scrvusd, recover_tokens)
Only admin	set_personal_limit from non-vault-factory-admin
Only owner	Owner-gated call from non-owner (set_crvusd_vault)
Vault not allowed	New crvusd_vault not in the allowlist
Has active positions	set_crvusd_vault while positions exist
Bad pool_id	market.lt == 0
Not enough crvUSD	Insufficient backing without deposit_stablecoins flag
Beyond pool limit	Deposit exceeds cap
Debt made too high	Sanity: debt > 1.1 · additional_crvusd
No liquidity given	lt_shares == 0 from deposit
Cannot withdraw stables	Oracle broken, not opting into stablecoin path
Not enough crvUSD left	Backing would drop below requirement
Token not allowed	recover_tokens targets protected token
Oracle is broken	Global and per-pool oracle both fail
Zero shares	emergency_withdraw(0)

HybridVaultFactory.vy

HybridVaultFactory.vy reverts with these strings:

String	Cause
Already created	User already has a vault
Vault not allowed	crvusd_vault not in the allowlist
Vault impl not set	vault_impl == 0
Access	Non-ADMIN on admin function
Only vaults can call	update_* from non-registered vault
Vault wind-down	Requirement increase on disallowed vault
Beyond vault limit	Increase exceeds crvusd_vault_limits

HybridFactoryOwner.vy

HybridFactoryOwner.vy reverts with these strings:

String	Cause
Access	Caller is not ADMIN (the YB DAO). For lt_allocate_stablecoins on an enabled LT, the caller is neither ADMIN nor a limit setter
Not enough reserves	Deallocation of a disabled LT would drop the allocation below 3/4 of the LEVAMM oracle value

MigrationFactoryOwner.vy

MigrationFactoryOwner.vy reverts with these strings:

String	Cause
Access	Caller is not ADMIN
Not disabled	A non-admin calls lt_allocate_stablecoins(lt, 0) on an LT that is not disabled
Not enough reserves	Deallocation would drop the allocation below 3/4 of the LEVAMM oracle value

LTMigrator.vy

LTMigrator.vy reverts with these strings:

String	Cause
same LT	lt_from and lt_to are the same LT
lt_to deprecated	Migration target is disabled in the factory owner (disabled_lts(lt_to) is true)
lt_from not in factory	Source LT is not a factory market
lt_to superseded	lt_to is not the newest market for the asset. The deployed LTMigrator can run an older version without this rule; its address is in Contract addresses
not enough out	shares_out < min_out in migrate_staked

YBLendingOracle.vy

YBLendingOracle.vy reverts with these strings:

String	Cause
Zero	Constructor: the factory or the proxy implementation is the zero address
No market	create_oracles with market_id equal to or above Factory.market_count(), or for a market whose LT address is zero
AMM reentrancy	A price read while the market's LEVAMM holds its reentrancy lock (the check_nonreentrant() probe fails)

YBLendingOracleLL.vy

YBLendingOracleLL.vy reverts with these strings:

String	Cause
Initialized	Second initialize
Zero	initialize with the zero address as LT or factory
ema_time	initialize or set_ema_time with ema_time 0 or above MAX_EMA_TIME (10**9 s)
Only factory	set_ema_time from an address other than the factory
AMM reentrancy	A price read while the market's LEVAMM holds its reentrancy lock

YBLendingOracleLLFactory.vy

YBLendingOracleLLFactory.vy reverts with these strings:

String	Cause
Zero	Constructor with a zero factory, implementation, USD blueprint or DAO address; set_dao with the zero address
ema_time	Constructor or set_default_ema_time with default_ema_time 0 or above MAX_EMA_TIME
No market	create_oracles with market_id equal to or above Factory.market_count(), or for a market whose LT address is zero
Not DAO	set_dao, set_default_ema_time or set_ema_time from an address other than the DAO
No oracles	set_ema_time for a market that has no oracles

LTSwapZap.vy

LTSwapZap has no custom revert strings. Its owner-only functions revert with ownable: caller is not the owner (snekmate ownable).

DAO

YB.vy

YB.vy reverts with this string:

String	Cause
erc20: access is denied	emit not from a minter

VotingEscrow.vy

VotingEscrow.vy reverts with these strings:

String	Cause
Min value	create_lock value < UMAXTIME
Withdraw old tokens first	create_lock with existing lock
Can only lock until time in the future	unlock_time ≤ block time
Voting lock can be 4 years max	The new lock end is more than 4 years after the block time
No existing lock found	increase_amount on empty
Cannot add to expired lock. Withdraw	Expired lock
Nothing is locked	increase_unlock_time on empty
Lock expired	Expired lock
Can only increase lock duration	New end ≤ current end
Not allowed	infinite_lock_toggle blocked by clearance checker
The lock didn't expire	withdraw before expiry
Not supported	delegate / delegateBySig
erc721: caller is not token owner or approved	Transfer auth fail
Wrong token ID	Token ID mismatches owner's address
Need max veLock	Transfer with non-max or non-infinite locks
erc721: transfer to non-IERC721Receiver implementer	safeTransferFrom to a contract that does not accept the veYB NFT

This call reverts without a message:

• increase_amount with value < UMAXTIME, the same check as Min value.

GaugeController.vy

GaugeController.vy reverts with these strings:

String	Cause
Gauge already added	Duplicate gauge registration
Gauge not alive	checkpoint, or emit from a gauge, for a gauge that the GaugeController has not added (time_weight(gauge) == 0). Killing a gauge does not raise it
Vote checker not set	veYB's transfer_clearance_checker ≠ this
Mismatch in lengths	Array-length mismatch
Expired	User's veYB lock expired
Weight too large	Single weight > 10,000 bp
Killed	Voting for killed gauge
Gauge not added	Unregistered gauge (vote_for_gauge_weights or set_killed)
Cannot vote so often	Same-gauge re-vote within 10 days
Used too much power	Sum of veYB vote weights across gauges exceeds 10,000 bp (100%) after this vote

LiquidityGauge.vy

LiquidityGauge.vy reverts with these strings:

String	Cause
YB	add_reward / deposit_reward targets YB
LP_TOKEN	add_reward targets LT
Already added	Duplicate add_reward
Not added	change_reward_distributor for a token that was not added
No rewards	deposit_reward(0)
Finishes in the past	New finish time ≤ block time
Rate unknown	Extending past old finish time
No reward	Reward token has no distributor (it was not added); raised in reward checkpoints
erc4626: deposit/mint/withdraw/redeem more than maximum	The amount of deposit, mint, withdraw, or redeem is above the ERC-4626 maximum for that call, for example maxWithdraw(owner)
erc4626: leave MIN_SHARES	Gauge supply after the operation would be between 0 and MIN_SHARES (1e12)
ownable: caller is not the owner	Owner-only function from another address (snekmate ownable)
receiver	Kill-mode redeem with receiver ≠ owner
erc4626: transferFrom operation did not succeed	The LT-share transfer into the gauge failed in deposit or mint
erc4626: transfer operation did not succeed	The LT-share transfer out of the gauge failed in withdraw or redeem

FeeDistributor.vy

FeeDistributor.vy reverts with these strings:

String	Cause
Ded	fill_epochs when killed
Might be a vest	Fee claim routed through a vesting escrow when direct receiver rules do not allow it

InflationaryVest.vy

InflationaryVest.vy reverts with these strings:

String	Cause
Admin required	start / set_recipient from non-owner
Already started	Second start()

VestingEscrow.vy

VestingEscrow.vy reverts with these strings:

String	Cause
Lengths mismatch	fund with mismatched arrays
Rugged	The call targets a recipient whose tokens rug_disabled already reclaimed
Disabled	fund for a recipient that is disabled
Cannot disable	toggle_disable when can_disable = False
Not disabled	rug_disabled for a recipient that is not disabled

CliffEscrow.vy

CliffEscrow.vy reverts with these strings:

String	Cause
Empty recipient	initialize(recipient=0)
Already initialized	A second initialize call
Cliff still applies	Transfer/approve before unlock_time
Not authorized	Non-recipient ve op
Cannot recover YB	recover_token(YB)

SnapshotSplitter.vy

SnapshotSplitter.vy reverts with this string:

String	Cause
Already claimed	claim for an address that already claimed

CallComparator.vy

CallComparator.vy reverts with these strings:

String	Cause
Not equal	check_equal
Equal	check_nonequal
Not greater	check_gt
Not less	check_lt
Timestamp not greater	check_timestamp_gt
Timestamp not less	check_timestamp_lt
Too early	check_called_after rate limit

TokenSender, Multisend, StakeZap

These contracts have no custom revert strings. A call fails when a token transfer that it makes reverts.

Net pressure

Owner-only functions of FeeSplitter, MerklPIDDriver, and PID revert with ownable: caller is not the owner (snekmate ownable).

FeeSplitter.vy

FeeSplitter.vy reverts with this string:

String	Cause
fraction > 1	Constructor or set_split_fraction with split_fraction above PRECISION (10**18, which is 100%)

MerklPIDDriver.vy

MerklPIDDriver.vy reverts with these strings:

String	Cause
Not manager	A function for the owner or the manager (approve_merkl, accept_conditions, create_campaign, override_campaign, set_gains, set_execution_params) from another caller
No wrapper	approve_merkl while no reward wrapper is set
No pools	preview_target_apr while half_tvl is 0

PID.vy

PID.vy reverts with this string:

String	Cause
No pools	trigger or preview_signals while half_tvl is 0

FastGauge.vy

FastGauge.vy reverts with these strings:

String	Cause
Below min supply	Gauge supply after the operation would be above 0 and below MIN_TOTAL_SUPPLY (10 × 10**18)
Only PID	set_reward_rate from an address other than pid
ema_time	set_ema_time(0)
No zap: LP is not a pool	add_liquidity, remove_liquidity or remove_liquidity_one_coin while ZAP_ENABLED is false
Bad amounts length	add_liquidity with amounts of a length other than POOL_N_COINS
Bad min_amounts length	remove_liquidity with min_amounts of a length other than POOL_N_COINS
erc4626: deposit/mint/withdraw/redeem more than maximum	The amount of deposit, mint, withdraw, or redeem is above the ERC-4626 maximum for that call, for example maxWithdraw(owner)
erc4626: transferFrom operation did not succeed	The LP-token transfer into the gauge failed in deposit or mint
erc4626: transfer operation did not succeed	The LP-token transfer out of the gauge failed in withdraw or redeem

YBNetPressure.vy

YBNetPressure.vy reverts with this string:

String	Cause
AMM reentrancy	A read (net_pressure_oracle, net_pressure_naive, net_pressure_and_tvl, half_tvl_oracle, crvusd_value_fraction) while the market's LEVAMM holds its reentrancy lock

MarketRateGetter.vy

MarketRateGetter.vy reverts with this string:

String	Cause
Bad ssr	Constructor: susds.ssr() is below RAY (10**27)

Curve pool (Twocrypto with policy hook)

These strings come from the Curve Twocrypto v3.0.0 pools of markets 7 to 10. The pools of markets 0 to 6 run older code. To check the version of a pool, call version() on it.

A v3.0.0 pool reverts with these strings:

String	Cause
!amounts	add_liquidity with both amounts 0
!wl	LP allowlist is on and msg.sender is not on it (not checked for donations)
!init	First add_liquidity to a pool that is not initialized
nothing minted	add_liquidity mints 0 LP
nonzero receiver	Donation with a receiver other than the zero address
donation above cap!	Donation shares would exceed donation_shares_max_ratio of supply
slippage	Output below the caller's minimum in add_liquidity, remove_liquidity, remove_liquidity_fixed_out, remove_liquidity_one_coin or exchange
!coins	exchange_received: the pool did not receive at least dx before the call
same coin	exchange with i == j
zero dx	exchange with zero input received
negative donation	Internal check in tweak_price: boosted virtual price below virtual price
tweaked supply must shrink	Internal check when the pool burns donation shares
!amount	remove_liquidity_fixed_out or remove_liquidity_one_coin (and their calc_ views) with more LP than the total supply
!tokens	Fixed-output or one-coin removal that computes both amounts as 0
!receiver	LP-token transfer to the pool itself or to the zero address
!transferFrom	The token transfer into the pool failed
!transfer	The token transfer out of the pool failed
!balance	After the operation, a balance is 0, or the scaled balances differ by 1,000:1 or more
only owner	Admin function (set_policy_contract, change_allowlist, set_fee_parameters, parameter changes) not from the Curve factory admin

These calls revert without a message:

• A balanced removal, if the best-effort policy callback fails and less than 500,000 gas remained before the call (assert gas_before_policy_call >= 500_000).
• An admin call that fails a parameter check.

pool.get_dy and pool.get_dx run in the pool's view contract. They can revert with coin index out of range, do not exchange 0 coins, do not exchange out 0 coins, or unsafe value for y.

Pool policies

These strings come from the policy contract attached to a Curve pool (pool.POLICY()). For the checks behind them, read Pool policy.

YBOraclizedPolicy

These strings apply to a pool that runs the oracle-report policy. To see which policy a pool runs, call POLICY() on the pool or read the pool policy table in Contract addresses.

YBOraclizedPolicy reverts with these strings:

String	Cause
LT deviation	An LT.deposit debt differs from the proportional debt added_lp * AMM.get_debt() / AMM.collateral_amount() by more than ratio_tolerance. Raised inside the pool's add_liquidity. Compute debt as in Compute debt on a pool that runs the oracle-report policy
auth!	update_pool_state caller is not the pool
killed	deliver_oracle_report while the policy is killed
pool uninitialized	deliver_oracle_report, sync or a revive (set_killed(False)) while the pool price_scale is 0. Inside a pool operation, sync and deliver_oracle_report revert on the pool's reentrancy lock instead
report length	Report is shorter than 112 bytes
signer	The verifier returned the zero address as signer
payload length	Signed payload is not 41 bytes
payload magic	Payload does not start with the Pyth Lazer magic 0x93c7d375
channel	Payload channel is not oracle.channel. Also raised by set_oracle_config for a channel outside 1 to 4
one feed	Payload has more or less than one feed
feed	Feed id is not FEED_ID
price property, exponent property, observation property	Payload properties are missing or in another order (required: price, exponent, feed update time)
price/exponent	Price mantissa is not positive, or exponent is outside −18 to 0
report time	Observation time is 0, observation is after the message time, or the message time is more than future_window_us after the block
report too old	Observation is more than past_window_us before the block
observation not newer	The stored report (or the watermark after a kill) is at least as new
price bounds	Report price is outside oracle.min_price to oracle.max_price. Also raised by set_oracle_config for bounds outside $1e-12 to $1e12 or min_price > max_price
access	set_killed caller is not the owner or the emergency admin
ownable: caller is not the owner	set_policy_config, set_oracle_config or an ownership function from a non-owner
coin index out of range	get_dy_with_report* with i == j or an index above 1
not attached	get_dy_with_report* while pool.POLICY() is not this policy
unsafe value for y	get_dy_with_report* with dx that drains the output coin
base fee	set_policy_config: base_fee below 0.1 bp or above fallback_fee
fallback fee	set_policy_config: fallback_fee above 10%
capture	set_policy_config: capture above 100%
relax time	set_policy_config: relax_time is 0 or above 3,600 s
fast half-life	set_policy_config: fast half-life below 600 s or above the slow half-life
slow half-life	set_policy_config: slow half-life above 604,800 s
trend gate	set_policy_config: trend_gate above 10%
step cap	set_policy_config: step_cap is 0 or above 60 bp
report lifetime	set_policy_config: report_lifetime above 14,400 s
ratio tolerance	set_policy_config: ratio_tolerance above 10 bp
verifier	set_oracle_config: verifier is not a contract
past window	set_oracle_config: past_window_us above 12,000,000
future window	set_oracle_config: future_window_us above 6,000,000
pool=0, feed id, emergency admin=0, amm collateral, amm stablecoin, pool precision, admin fee	Constructor checks

The Pyth Pro (Pyth Lazer) verifier can revert deliver_oracle_report with its own errors, for example on a wrong msg.value or a bad signature. The deployed verifier (implementation 0xD8f4A467AbeC64Bc944eee1325B9007879B6555b, PythLazer 0.2.0) has these strings: Insufficient fee provided, input too short, invalid evm magic, invalid signature, invalid signer. input too short and invalid evm magic mean that the update is not in EVM format. invalid signature and invalid signer mean that the signature does not recover to a trusted Pyth signer.

These calls revert without a message:

• A call with a report longer than 112 bytes, in ABI decoding.
• deliver_oracle_report on verifier 0.2.0 with a msg.value above verification_fee(), because the refund to the policy fails.

For the exact-fee rule, how a later verifier version differs, and how to check the version, read Verification fee in Oracle report arbitrage.

YBTwocryptoPolicy

YBTwocryptoPolicy sets only the price_scale target, from the pool's own prices. It reverts with these strings:

String	Cause
auth!	update_pool_state caller is not the pool
pool=0, fast half-life, slow half-life, half-life order, kappa, deadband, max cap, min cap	Constructor checks

Related

• Event catalog: the events of the same contracts, with topic0 hashes.
• Deposit and withdraw: the deposit and withdrawal reverts at the calls that raise them.
• Pool policy: the policy checks behind the policy strings.
• Oracle report arbitrage: the deliver-and-swap procedure, and the admission rules in the order a delivery checks them.
• LT contract reference: the LT functions that raise most core strings.