> ## Documentation Index
> Fetch the complete documentation index at: https://docs.compose.market/llms.txt
> Use this file to discover all available pages before exploring further.

# Compose Keys

> Bearer token authentication — no wallet signing needed for each call.

A Compose Key is a JWT bearer token that handles payment server-side. You create it once with your wallet address and chain ID, then the SDK attaches it to every request as `Authorization: Bearer compose-<jwt>`.

## Create a key

```typescript theme={null}
const { token, keyId } = await sdk.keys.create({
  userAddress: "0xYourWalletAddress",
  chainId: 43113,
});

// The SDK stores the token automatically.
// In a browser: persisted in localStorage.
// In Node.js: kept in memory for the process lifetime.
```

## Pass an existing key

If you already have a token (e.g., from a previous session or another service):

```typescript theme={null}
const sdk = new ComposeSDK({
  userAddress: "0xYourWalletAddress",
  chainId: 43113,
  key: "compose-eyJhbGci...",
});
```

## List keys

```typescript theme={null}
const { keys } = await sdk.keys.list();
// keys: [{ keyId, createdAt, lastUsedAt, revokedAt }]
```

## Revoke a key

```typescript theme={null}
await sdk.keys.revoke({ keyId });
```

## Check active session

```typescript theme={null}
const session = await sdk.keys.session();
// session: { hasSession, token, budgetLimit, budgetUsed, budgetRemaining, expiresAt }
```

## Token storage

The SDK auto-detects `localStorage` in browser environments and persists the token under `compose:token:<userAddress>:<chainId>`. In Node.js, tokens are kept in memory.

To use a custom storage adapter (e.g., a database or secure enclave):

```typescript theme={null}
const sdk = new ComposeSDK({
  userAddress: "0xYourWalletAddress",
  chainId: 43113,
  storage: {
    get: async (key) => db.get(key),
    set: async (key, value) => db.set(key, value),
    delete: async (key) => db.delete(key),
  },
});
```

## When to use Compose Keys vs raw x402

| Compose Key                        | Raw x402                               |
| ---------------------------------- | -------------------------------------- |
| Human-facing apps                  | Agent-to-agent automation              |
| Web integrations with localStorage | Server-side scripts                    |
| No wallet signing per call         | No pre-registered token                |
| Budget limits per session          | Pay exactly what you use               |
| Token can expire or be revoked     | Works as long as the channel has funds |

Use Compose Keys when a human is involved. Use raw x402 when machines talk to machines.