Isolated Pools

This section documents the PoolRegistry → Comptroller → VToken architecture from the isolated-pools repository. Despite the historical directory name, this architecture is not deprecated: it powers the Core Pool on every supported mainnet except the legacy BNB Chain Core Pool.

Do not confuse these two lifecycle decisions:

the old, separately promoted Isolated Pools product on BNB Chain, Ethereum, and Arbitrum is retired; use the exit guide for positions that still need to be closed;
the lending market engine remains active for modern Core Pools and for any retired pool that still has balances, debt, rewards, or recovery duties.

BNB Chain’s legacy Core Pool uses the Unitroller/Diamond Comptroller and legacy VTokens, not the contracts in this section.

Runtime topology

PoolRegistry transparent proxy
  └─ registered Comptroller beacon proxies (one per pool)
       └─ VToken beacon proxies (one per market)
            └─ an interest-rate-model contract per market

PoolLens is a separate read helper. It is not a proxy, and old Lens deployments can coexist with newer ones. Resolve the exact address and tuple ABI before decoding its output.

Mainnet implementation map

The following proxy and beacon state was read directly from each chain on August 27, 2026. Addresses in a deployment artifact are not a substitute for these indirections: governance can upgrade a proxy or beacon without changing the user-facing proxy address.

Network	Checked block	PoolRegistry proxy	Implementation
BNB Chain	`118365741`	`0x9F7b01A536aFA00EF10310A162877fd792cD0666`	`0xc4953e157D057941A9a71273B0aF4d4477ED2770`
Ethereum	`25845889`	`0x61CAff113CCaf05FFc6540302c37adcf077C5179`	`0x08A2577611Ae63d1ba40188035eD6Ad21F8502A9`
Arbitrum One	`498885126`	`0x382238f07Bc4Fe4aA99e561adE8A4164b5f815DA`	`0xc9A9594e774F9454e4665126C72Eb62643253aB0`
Optimism	`156113433`	`0x147780799840d541C1d7c998F0cbA996d11D62bb`	`0x6a166fcd39BA9c4ACc1b98eC45Adcdc4926E7967`
Base	`50518148`	`0xeef902918DdeCD773D4B422aa1C6e1673EB9136F`	`0x88eF9Fd7004f81c1B1CA59375178425C97A7eE68`
opBNB	`178834850`	`0x345a030Ad22e2317ac52811AC41C1A63cfa13aEe`	`0xc5A64235ff4aad92b71eC69a925224b60aede1aa`
zkSync Era	`71738270`	`0xFD96B926298034aed9bBe0Cca4b651E41eB87Bc4`	`0x204Dfdbb0F066dAfaD8C7fc07B04751A973ADCFb`
Unichain	`57077285`	`0x0C52403E16BcB8007C1e54887E1dFC1eC9765D7C`	`0xBAb8c229B6C19c443b942F228B076Ca0d4f2260E`

Network	Comptroller beacon → implementation	VToken beacon → implementation	VToken clock
BNB Chain	`0x38B4Efab9ea1bAcD19dC81f19c4D1C2F9DeAe1B2` → `0x7B586Aed00C85d7E32B463DCE094B1faCA7e7e7c`	`0x2b8A1C539ABaC89CbF7E2Bc6987A0A38A5e660D4` → `0x228Ea224d62D14a2e2cb9B43083aE43954C39B67`	block, `42,048,000`/year
Ethereum	`0xAE2C3F21896c02510aA187BdA0791cDA77083708` → `0xC910F2B196C516253e88b2097ba5D7d5fC9fa84e`	`0xfc08aADC7a1A93857f6296C3fb78aBA1d286533a` → `0x33bE30B31f07c8a2bfb705FBcE55E983c47ba864`	block, `2,628,000`/year
Arbitrum One	`0x8b6c2E8672504523Ca3a29a5527EcF47fC7d43FC` → `0x4b256a7836415e09DabA40541eE78602Bc6B24bF`	`0xE9381D8CA7006c12Ae9eB97890575E705996fa66` → `0x1986Fb53535953711265d5fD329cd7A690411669`	second, `31,536,000`/year
Optimism	`0x64f9306496ccF7b7369d02d68D6abcA2Edfb871d` → `0x4D3f690A33A365Fc131777ea6e0f5B8821eb755b`	`0xd550Bdfa9402e215De0BabCb99F7294BE0268367` → `0xBEB9eE824a0096c0FB606b070c028cB55b6f21e7`	second, `31,536,000`/year
Base	`0x1b6dE1C670db291bcbF793320a42dbBD858E67aC` → `0x93177BFDBc5dAf7B0fF4A09478eF90FF6e28E04A`	`0x87a6476510368c4Bfb70d04A3B0e5a881eC7f0d1` → `0x107bA74c87e75b6cc291510D3A85D0c8EAa73e82`	second, `31,536,000`/year
opBNB	`0x11C3e19236ce17729FC66b74B537de00C54d44e7` → `0xD3b2431c186A2bDEB61b86D9B042B75C954004F6`	`0xfeD1d3a13597c5aBc893Af41ED5cb17e64c847c7` → `0x7AA7EB7553DE5f221C06595f3b4021363279e9Fe`	block, `126,144,000`/year
zkSync Era	`0x0221415aF47FD261dD39B72018423dADe5d937c5` → `0xB2B58B15667e39dc09A0e29f1863eee7FD495541`	`0x53523537aa330640B80400EB8B309fF5896E7eb5` → `0x3e9cf1eBe018610585D0B519A9956C950E079591`	second, `31,536,000`/year
Unichain	`0xE57824ffF03fB19D7f93139A017a7E70f6F25166` → `0xDa42d85AE7625eBDD3b5967F44c263565BD8fA40`	`0x42c1Efb9Dd9424c5ac8e6EcEa4eb03940c4a15Fc` → `0x256E61f4056EC9eaB8c56E3aFa217a12c33b8893`	second, `31,536,000`/year

One important exception to the v4.4.0 deployment artifacts is BNB Chain: its VToken beacon currently points to the implementation installed by VIP-524, not to the BNB artifact committed in the repository release.

How to use this reference

Treat a registry entry as discovery data, not proof that a pool is open for new use.
Resolve the current proxy or beacon implementation at the block used by your integration.
Use “slot” for rate and accrual units until isTimeBased() establishes whether a slot is a block or a second.
Use the deployed markets registry for market addresses, then confirm listing, pause, caps, balances, and debt onchain.
Use compiler build information for storage-layout review. A list of public getters is not a safe upgrade layout.

The stable API descriptions in this section are aligned with the isolated-pools v4.4.0 source. Pages call out deployment exceptions where the live implementation differs.