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

> ## Agent Instructions
> Before reading these docs, install the relevant Circle Skill to get pre-loaded context — skills are LLM-optimized and cover architecture decisions, correct flows, and common pitfalls. In Claude Code: run /plugin marketplace add circlefin/skills then /plugin install circle-skills@circle. With Vercel Skills CLI: run npx skills add circlefin/skills. Available skills: use-usdc https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-usdc/SKILL.md (balances, transfers, approvals on EVM and Solana); EURC has no skill — see https://developers.circle.com/stablecoins/what-is-eurc.md; bridge-stablecoin https://github.com/circlefin/skills/blob/master/plugins/circle/skills/bridge-stablecoin/SKILL.md (crosschain transfers via CCTP, USDC, EURC, and third-party assets); use-arc https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-arc/SKILL.md (Arc chain config, contract deployment, USDC bridging — Arc docs: https://docs.arc.io/llms.txt); use-circle-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-circle-wallets/SKILL.md (choose wallet type); use-developer-controlled-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-developer-controlled-wallets/SKILL.md (custodial wallets for payouts and treasury); use-user-controlled-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-user-controlled-wallets/SKILL.md (embedded wallets with Web2 login); use-modular-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-modular-wallets/SKILL.md (smart contract wallets with passkeys and ERC-4337); use-gateway https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-gateway/SKILL.md (unified USDC balance, nanopayments); use-smart-contract-platform https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-smart-contract-platform/SKILL.md (deploy, interact, monitor contracts). Pair any skill with the Circle MCP server for live SDK signatures, contract addresses, and chain IDs: {"mcpServers":{"circle":{"url":"https://api.circle.com/v1/codegen/mcp"}}}.
> Read the product overview first. Each product has an overview explaining when and why to use it. Read it before quickstarts.
> Pick the right wallet type. Developer-controlled (you hold keys), user-controlled (end user holds keys via PIN/social login), or modular (smart contract wallets with passkeys). See https://developers.circle.com/wallets.md.
> Use CCTP V2 for crosschain transfers. CCTP natively transfers USDC and EURC via burn-and-mint, and supports permissionless wrapping of third-party assets via lock-and-mint. V1 is legacy; always use V2 unless V1 is specified or the chain requires it (Noble, Sui, and Aptos still require V1). Migration guide: https://developers.circle.com/cctp/migration-from-v1-to-v2.md.
> Use Bridge Kit for frontend bridging. Wraps CCTP with a simpler SDK for user-facing apps. Use CCTP directly for backend transfers.
> Gas Station vs Paymaster. Gas Station sponsors gas for Circle Wallet transactions. Paymaster lets users pay gas in USDC. Different use cases — read both overviews.
> Gateway Nanopayments for sub-cent payments. Gasless USDC micropayments down to $0.000001 via x402 and batched settlement. For pay-per-request APIs, AI agent payments, streaming.
> Look up USDC addresses per chain. Never hardcode — use https://developers.circle.com/stablecoins/usdc-contract-addresses.md.
> Prefer SDKs over raw API calls. Node.js and Python SDKs handle auth, retries, and errors.
> API key required. Bearer token in Authorization header. Testnet and mainnet use separate keys and may use different base URLs depending on the product.
> Set up webhooks when available. Most operations are async. Webhooks deliver transaction confirmations and state changes.
> When calling list endpoints, paginate using pageSize and pageAfter until no nextPageAfter cursor is returned—stopping at the first page silently misses records.
> Building an AI agent? Start with the Agent Stack—Circle CLI, agent wallets, and nanopayments built for autonomous use cases: https://developers.circle.com/agent-stack.md.

# Token IDs

> Token IDs are Circle's unique identifiers for tokens across blockchains. Reference tables of USDC, EURC, and native token IDs and how to scope wallet responses with monitored tokens.

A token ID is a UUID that uniquely identifies a token across blockchains in
Circle Wallets. The Wallets API uses the token ID anywhere it references a
specific token, including
[balance lookups](/api-reference/wallets/developer-controlled-wallets/list-wallet-balance),
[transaction lists](/api-reference/wallets/developer-controlled-wallets/list-transactions),
and
[monitored token configuration](/api-reference/wallets/programmable-wallets/list-monitored-tokens).

For each blockchain's chain code, see
[Supported blockchains](/wallets/supported-blockchains).

<Note>
  Arc uses
  [USDC as its native gas token](https://docs.arc.io/arc/concepts/stablecoin-native-model#usdc-as-the-native-gas-token),
  so an Arc wallet's USDC appears twice in the Wallets API: once as the native
  token and once as an ERC-20. Both entries reference the same underlying USDC
  balance. They aren't separate assets, and gas payments don't charge the wallet
  twice.
</Note>

## USDC token IDs

The following tables list the USDC token ID and contract address on each
supported blockchain.

### Mainnet

| Blockchain | Token ID | Token address |
| - | - | - |
| Aptos | `298eebe2-3131-5183-b528-f925f70848d0` | [`0xbae207659db88bea0cbead6da0ed00aac12edcdda169e591cd41c94180b46f3b`](https://explorer.aptoslabs.com/fungible_asset/0xbae207659db88bea0cbead6da0ed00aac12edcdda169e591cd41c94180b46f3b?network=mainnet) |
| Arbitrum | `c87ffcb4-e2cf-5e67-84c6-388c965d2a66` | [`0xaf88d065e77c8cC2239327C5EDb3A432268e5831`](https://arbiscan.io/token/0xaf88d065e77c8cC2239327C5EDb3A432268e5831) |
| Arc | `5677d668-490d-51d3-82c7-b2b8313df2f4` | [`0x3600000000000000000000000000000000000000`](https://explorer.arc.io/address/0x3600000000000000000000000000000000000000) |
| Avalanche | `7efdfdbf-1799-5089-a588-31beb97ba755` | [`0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E`](https://snowtrace.io/token/0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E) |
| Base | `aa7bb533-aeb8-535c-bd65-354aed91ea3d` | [`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`](https://basescan.org/token/0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) |
| Ethereum | `b037d751-fb22-5f0d-bae6-47373e7ae3e3` | [`0xA0b86991c6218b36c1D19D4a2e9Eb0cE3606eB48`](https://etherscan.io/token/0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48) |
| Monad | `95401815-48ec-59eb-a06c-8fd1a8e82a8f` | [`0x754704Bc059F8C67012fEd69BC8A327a5aafb603`](https://monadvision.com/token/0x754704Bc059F8C67012fEd69BC8A327a5aafb603) |
| Optimism | `63ca9c9c-2f6d-594f-9070-ff2a4042be3a` | [`0x0b2C639c533813f4Aa9D7837CAf62653d097Ff85`](https://optimistic.etherscan.io/token/0x0b2C639c533813f4Aa9D7837CAf62653d097Ff85) |
| Polygon PoS | `db6905b9-8bcd-5537-8b08-f5548bdf7925` | [`0x3c499c542cef5e3811e1192cE70d8cc03d5c3359`](https://polygonscan.com/token/0x3c499c542cef5e3811e1192ce70d8cc03d5c3359) |
| Solana | `33ca4ef6-2500-5d79-82bf-e3036139cc29` | [`EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v`](https://solscan.io/token/EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v) |
| Unichain | `643096e8-e4c5-5ee7-a5d5-38c80fdc3f3b` | [`0x078D782b760474a361dDA0AF3839290b0EF57AD6`](https://unichain.blockscout.com/address/0x078D782b760474a361dDA0AF3839290b0EF57AD6) |

### Testnet

| Blockchain | Token ID | Token address |
| - | - | - |
| Aptos Testnet | `e3cbdafc-42c3-58cc-ae4c-b31dbb10354c` | [`0x69091fbab5f7d635ee7ac5098cf0c1efbe31d68fec0f2cd565e8d168daf52832`](https://explorer.aptoslabs.com/fungible_asset/0x69091fbab5f7d635ee7ac5098cf0c1efbe31d68fec0f2cd565e8d168daf52832?network=testnet) |
| Arbitrum Sepolia | `4b8daacc-5f47-5909-a3ba-30d171ebad98` | [`0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d`](https://sepolia.arbiscan.io/address/0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d) |
| Arc Testnet | `ef87c8c3-85de-598a-af50-c5135eecfa74` | [`0x3600000000000000000000000000000000000000`](https://explorer.testnet.arc.io/address/0x3600000000000000000000000000000000000000) |
| Avalanche Fuji | `ff47a560-9795-5b7c-adfc-8f47dad9e06a` | [`0x5425890298aed601595a70ab815c96711a31bc65`](https://testnet.snowtrace.io/token/0x5425890298aed601595a70ab815c96711a31bc65) |
| Base Sepolia | `bdf128b4-827b-5267-8f9e-243694989b5f` | [`0x036CbD53842c5426634e7929541eC2318f3dCF7e`](https://base-sepolia.blockscout.com/address/0x036CbD53842c5426634e7929541eC2318f3dCF7e) |
| Ethereum Sepolia | `5797fbd6-3795-519d-84ca-ec4c5f80c3b1` | [`0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238`](https://sepolia.etherscan.io/address/0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238) |
| Monad Testnet | `17fe0589-b511-546c-9eff-84087524f47e` | [`0x534b2f3A21130d7a60830c2Df862319e593943A3`](https://testnet.monadexplorer.com/token/0x534b2f3A21130d7a60830c2Df862319e593943A3) |
| Optimism Sepolia | `20749a68-e55b-57d3-8359-195543efc2d4` | [`0x5fd84259d66Cd46123540766Be93DFE6D43130D7`](https://sepolia-optimism.etherscan.io/address/0x5fd84259d66Cd46123540766Be93DFE6D43130D7) |
| Polygon PoS Amoy | `36b6931a-873a-56a8-8a27-b706b17104ee` | [`0x41E94Eb019C0762f9Bfcf9Fb1E58725BfB0e7582`](https://amoy.polygonscan.com/address/0x41e94eb019c0762f9bfcf9fb1e58725bfb0e7582) |
| Solana Devnet | `8fb3cadb-0ef4-573d-8fcd-e194f961c728` | [`4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU`](https://explorer.solana.com/address/4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU?cluster=devnet) |
| Unichain Sepolia | `13ef30cd-309b-5c41-98cc-0fd68c4c8c44` | [`0x31d0220469e10c4E71834a79b1f276d740d3768F`](https://unichain-sepolia.blockscout.com/token/0x31d0220469e10c4E71834a79b1f276d740d3768F) |

## EURC token IDs

The following tables list the EURC token ID and contract address on each
supported blockchain.

### Mainnet

| Blockchain | Token ID | Token address |
| - | - | - |
| Avalanche | `0a6f40c3-3952-5033-b08e-da5bf01c905f` | [`0xC891EB4cbdEFf6e073e859e987815Ed1505c2ACD`](https://snowtrace.io/token/0xC891EB4cbdEFf6e073e859e987815Ed1505c2ACD) |
| Base | `9e1530d7-6961-5b5d-8434-f9ad12055294` | [`0x60a3E35Cc302bFA44Cb288Bc5a4F316Fdb1adb42`](https://basescan.org/token/0x60a3E35Cc302bFA44Cb288Bc5a4F316Fdb1adb42) |
| Ethereum | `df63715d-ad2e-50ae-a183-f677905aafc6` | [`0x1aBaEA1f7C830bD89Acc67eC4af516284b1bC33c`](https://etherscan.io/token/0x1aBaEA1f7C830bD89Acc67eC4af516284b1bC33c) |
| Solana | `c20b5a23-408c-518d-8add-0d0857c8666e` | [`HzwqbKZw8HxMN6bF2yFZNrht3c2iXXzpKcFu7uBEDKtr`](https://solscan.io/token/HzwqbKZw8HxMN6bF2yFZNrht3c2iXXzpKcFu7uBEDKtr) |

### Testnet

| Blockchain | Token ID | Token address |
| - | - | - |
| Arc Testnet | `4ea52a96-e6ae-56dc-8336-385bb238755f` | [`0x89B50855Aa3bE2F677cD6303Cec089B5F319D72a`](https://explorer.testnet.arc.io/address/0x89B50855Aa3bE2F677cD6303Cec089B5F319D72a) |
| Avalanche Fuji | `9a930659-ee2a-5127-b5e7-365a14d1f7b3` | [`0x5E44db7996c682E92a960b65AC713a54AD815c6B`](https://testnet.snowtrace.io/token/0x5E44db7996c682E92a960b65AC713a54AD815c6B) |
| Base Sepolia | `5b1ba740-7bb7-5695-bd2b-09243ce0f079` | [`0x808456652fdb597867f38412077A9182bf77359F`](https://base-sepolia.blockscout.com/address/0x808456652fdb597867f38412077A9182bf77359F) |
| Ethereum Sepolia | `c22b378a-843a-59b6-aaf5-bcba622729e6` | [`0x08210F9170F89Ab7658F0B5E3fF39b0E03C594D4`](https://sepolia.etherscan.io/address/0x08210F9170F89Ab7658F0B5E3fF39b0E03C594D4) |
| Solana Devnet | `6d0dbfb0-faee-5f0d-b60b-0fd5cd8430e5` | [`HzwqbKZw8HxMN6bF2yFZNrht3c2iXXzpKcFu7uBEDKtr`](https://explorer.solana.com/address/HzwqbKZw8HxMN6bF2yFZNrht3c2iXXzpKcFu7uBEDKtr?cluster=devnet) |

## Native token IDs

The following tables list the native token ID on each supported blockchain.

### Mainnet

| Blockchain | Native token | Token ID |
| - | - | - |
| Aptos | `APT` | `e963dad3-9eab-5b19-9613-95b1ad91aaee` |
| Arbitrum | `ETH` | `b4f0f691-4398-5c5f-959a-be991be28d2f` |
| Arc | `USDC` | `a912defc-9f51-5e87-a884-5937000a3a36` |
| Avalanche | `AVAX` | `3bd775d6-d6e9-5095-ac09-b162e79debf7` |
| Base | `ETH` | `5b5a3157-72da-5e34-a9f0-806296910b7e` |
| Ethereum | `ETH` | `b18e71aa-c9a9-5f58-a02c-21b2f9e349e1` |
| Monad | `MON` | `116169ec-f0ee-5b9c-8d99-52a23fbdc206` |
| Optimism | `ETH` | `ebbac2b2-3621-57c2-af85-ecf4a3dbdf3c` |
| Polygon PoS | `POL` | `ab91b710-3322-50b9-8a55-4bff56cd4c16` |
| Solana | `SOL` | `6b141f45-ff18-526a-8d1d-dd964788d05c` |
| Unichain | `ETH` | `1771ea31-4962-5ab8-99e7-7cde889fdf99` |

### Testnet

| Blockchain | Native token | Token ID |
| - | - | - |
| Aptos Testnet | `APT` | `d457a992-b109-50eb-b5aa-9ef4609e81d2` |
| Arbitrum Sepolia | `ETH` | `9ad91eb5-e152-5d81-b60e-151d5fd2b3d3` |
| Arc Testnet | `USDC` | `15dc2b5d-0994-58b0-bf8c-3a0501148ee8` |
| Avalanche Fuji | `AVAX` | `87a5c41c-fcb4-5973-8c66-72e2ed851ab8` |
| Base Sepolia | `ETH` | `f2ab11ae-53fa-5373-86e5-8b38447b65fb` |
| Ethereum Sepolia | `ETH` | `979869da-9115-5f7d-917d-12d434e56ae7` |
| Monad Testnet | `MON` | `8e87093c-64f1-5ddc-b0c2-54332fac04d0` |
| Optimism Sepolia | `ETH` | `ba2d9061-60ed-53b3-bade-4ad2305ffaf1` |
| Polygon PoS Amoy | `POL` | `0c8f8485-f74f-5e28-80f2-3cc4e80ef71c` |
| Solana Devnet | `SOL` | `ecf919b4-517f-5fde-b82b-393d1092e5fc` |
| Unichain Sepolia | `ETH` | `1f9d5ff4-7957-5ac6-9aee-e742af3772e7` |

## Find a token ID

The preceding tables provide a manual reference. The Wallets API also returns
the token ID alongside each token a wallet holds (native tokens, USDC, other
`ERC-20`s, and NFTs) in responses from:

* [`GET /wallets/{id}/balances`](/api-reference/wallets/developer-controlled-wallets/list-wallet-balance)
* [`GET /wallets/{id}/nfts`](/api-reference/wallets/developer-controlled-wallets/list-wallet-nfts)
* [`GET /transactions`](/api-reference/wallets/developer-controlled-wallets/list-transactions)

<Tip>
  Cache the token IDs your integration uses. Token IDs are stable, so a local
  lookup is faster than calling the Wallets API on every request.
</Tip>

## Monitored tokens

By default, the Wallets API returns every token held in a wallet across balance,
NFT, and transaction responses. Use monitored tokens to narrow that scope so the
Wallets API only surfaces tokens your integration depends on (for example, to
hide unrelated assets from end users). Token IDs are how you reference each
token when managing the monitored list.

Use the following endpoints to manage the monitored token list:

| Action | Endpoint | Behavior |
| - | - | - |
| Get the current list | [`GET /config/entity/monitoredTokens`](/api-reference/wallets/programmable-wallets/list-monitored-tokens) | Returns the configured token IDs. Returns `204 No Content` when no tokens have been added. |
| Add tokens | [`POST /config/entity/monitoredTokens`](/api-reference/wallets/programmable-wallets/create-monitored-tokens) | Adds the specified token IDs to the list. |
| Remove tokens | [`POST /config/entity/monitoredTokens/delete`](/api-reference/wallets/programmable-wallets/delete-monitored-tokens) | Removes the specified token IDs from the list. |
| Replace the list | [`PUT /config/entity/monitoredTokens`](/api-reference/wallets/programmable-wallets/update-monitored-tokens) | Overwrites the list with the specified token IDs. |
| Change the scope | [`PUT /config/entity/monitoredTokens/scope`](/api-reference/wallets/programmable-wallets/update-monitored-tokens-scope) | Sets the scope to `SELECTED` (only monitored tokens appear in responses) or `MONITOR_ALL` (every token appears, default). |

Adding a token automatically sets the scope to `SELECTED`. To temporarily
include every token in a single response, set `includeAll=true` on
[`GET /wallets/{id}/balances`](/api-reference/wallets/developer-controlled-wallets/list-wallet-balance),
[`GET /wallets/{id}/nfts`](/api-reference/wallets/developer-controlled-wallets/list-wallet-nfts),
or
[`GET /transactions`](/api-reference/wallets/developer-controlled-wallets/list-transactions).