# Token Management

> Markdown export of the Gearbox Protocol documentation page for agents and retrieval systems.

Canonical page: https://docs.gearbox.finance/developers/gm-mc-tokens
Source file: content/developers/gm-mc-tokens.mdx
Section router: https://docs.gearbox.finance/developers/llms.txt
Section full export: https://docs.gearbox.finance/developers/llms-full.txt

Manage which tokens count as collateral and revoke unnecessary token allowances on your credit account.

## Enabling and Disabling Tokens

### Why

You manually enable/disable tokens when:

* **Direct transfers** - Tokens sent directly to a Credit Account aren't auto-enabled
* **Gas optimization** - Disable unused tokens to reduce collateral check cost
* **Risk management** - Prevent certain tokens from counting in health factor

Most of the time you don't need this - tokens auto-enable/disable based on balance changes from adapter calls. Manual control is only necessary in edge cases.

### Auto-Enable/Disable Behavior

Non-quoted tokens have automatic behavior:

| Balance Change | Action       |
| -------------- | ------------ |
| 0/1 to > 1     | Auto-enable  |
| > 1 to 0/1     | Auto-disable |

**Important:** These functions only work on **non-quoted tokens**. Quota tokens can only be enabled/disabled via `updateQuota`.

### Enable a Token

```typescript
import { encodeFunctionData } from 'viem';
import { iCreditFacadeV300MulticallAbi } from '@gearbox-protocol/sdk';

const calls = [
  {
    target: creditFacadeAddress,
    callData: encodeFunctionData({
      abi: iCreditFacadeV300MulticallAbi,
      functionName: 'enableToken',
      args: [tokenAddress],
    }),
  },
];
```

### Disable a Token

```typescript
const calls = [
  {
    target: creditFacadeAddress,
    callData: encodeFunctionData({
      abi: iCreditFacadeV300MulticallAbi,
      functionName: 'disableToken',
      args: [tokenAddress],
    }),
  },
];
```

### Disable Unused Tokens to Save Gas

Each enabled token requires a price oracle call during collateral check. Disable tokens with zero balance:

```typescript
// Check which tokens have zero balance
const accountData = await service.getCreditAccountData(creditAccountAddress);

const tokensToDisable = accountData.tokens
  .filter(t => t.balance <= 1n && t.isEnabled)
  .map(t => t.token);

const calls = tokensToDisable.map(token => ({
  target: creditFacadeAddress,
  callData: encodeFunctionData({
    abi: iCreditFacadeV300MulticallAbi,
    functionName: 'disableToken',
    args: [token],
  }),
}));
```

### Enable/Disable Gotchas

* **No-op for quota tokens** - Calling `enableToken` or `disableToken` on a quota token does nothing. Use `updateQuota` instead.
* **Cannot enable forbidden tokens** - Forbidden tokens will revert. They must be swapped away.
* **Max enabled tokens limit** - Each Credit Manager has a maximum number of enabled tokens per account. Check with `creditManager.read.maxEnabledTokens()`.
* **Disabled tokens still on account** - Disabling doesn't remove the balance, it just excludes the token from the health factor calculation. During liquidation, liquidators can claim disabled token balances as bonus.
* **Balance of 1 is "zero"** - Gearbox treats balances of 0 and 1 the same (due to ERC20 rounding). Auto-disable triggers at balance <= 1.

---

## Revoking Allowances

### Why

You revoke allowances when:

* **Security incident** - A third-party contract may be compromised
* **Legacy cleanup** - Old accounts from V2.1 may have stale approvals
* **Defense in depth** - Proactively remove unnecessary approvals

Current Gearbox V3 automatically resets allowances to 1 after each interaction, so this is mainly needed for legacy accounts or incident response.

### How It Works

`revokeAdapterAllowances` resets token approvals from your Credit Account to specified contracts. Allowance is set to 1 (not 0) due to gas optimization.

### Basic Usage

```typescript
import { encodeFunctionData } from 'viem';
import { iCreditFacadeV300MulticallAbi } from '@gearbox-protocol/sdk';

// Define which approvals to revoke
const revocations = [
  {
    spender: uniswapRouterAddress,
    token: usdcAddress,
  },
  {
    spender: curvePoolAddress,
    token: daiAddress,
  },
];

const calls = [
  {
    target: creditFacadeAddress,
    callData: encodeFunctionData({
      abi: iCreditFacadeV300MulticallAbi,
      functionName: 'revokeAdapterAllowances',
      args: [revocations],
    }),
  },
];

await market.creditFacade.write.multicall([creditAccountAddress, calls]);
```

### Check Existing Allowances

```typescript
import { erc20Abi, getContract } from 'viem';

const token = getContract({
  address: tokenAddress,
  abi: erc20Abi,
  client: publicClient,
});

// Check allowance from Credit Account to a spender
const allowance = await token.read.allowance([
  creditAccountAddress,
  spenderAddress,
]);

if (allowance > 1n) {
  console.log(`Credit Account has ${allowance} allowance to ${spenderAddress}`);
}
```

### Revoke All Known Adapters

```typescript
// Get all adapters from Credit Manager
const adapters = await creditManager.read.adapters();

// Build revocations for all adapters
const revocations = adapters.map(adapter => ({
  spender: adapter,
  token: tokenAddress,
}));

const calls = [
  {
    target: creditFacadeAddress,
    callData: encodeFunctionData({
      abi: iCreditFacadeV300MulticallAbi,
      functionName: 'revokeAdapterAllowances',
      args: [revocations],
    }),
  },
];
```

### Revocation Gotchas

* **Usually not needed in V3** - Gearbox V3 automatically resets allowances after each adapter interaction.
* **Sets to 1, not 0** - For gas efficiency, allowances are set to 1 instead of 0. An allowance of 1 wei is functionally zero.
* **Target the adapter, not the protocol** - Revocations target the spender (adapter address), not the underlying protocol.
* **Batch multiple revocations** - Pass multiple `(spender, token)` pairs in a single `revokeAdapterAllowances` call for efficiency.

### When to Actually Revoke

Real scenarios where revocation makes sense:

1. **Third-party exploit** - A protocol Gearbox integrates with gets hacked
2. **Account migration** - Moving from V2.1 account with old allowances
3. **Compliance requirement** - Regulatory frameworks requiring revoked unused approvals
4. **Personal security policy** - Explicit control over all approvals

## Learn More

* [External Calls](https://docs.gearbox.finance/developers/gm-mc-external) - How adapters use allowances
* [Updating Quotas](https://docs.gearbox.finance/developers/gm-mc-quotas) - How to enable/disable quota tokens
* [Slippage & Safety](https://docs.gearbox.finance/developers/gm-mc-safety) - Related safety controls