> ## 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. # Get token details > Fetches details of a specific token given its unique identifier. Every token in your network of wallets has a UUID associated with it, regardless of whether it's already recognized or was added as a monitored token. ## OpenAPI ````yaml openapi/developer-controlled-wallets.yaml get /v1/w3s/tokens/{id} openapi: 3.0.3 info: version: '1.0' title: Developer-Controlled Wallets description: Developer-Controlled Wallets API documentation. servers: - url: https://api.circle.com security: - BearerAuth: [] tags: - name: Wallet Sets - name: Wallets - name: Signing - name: Transactions - name: Token Lookup paths: /v1/w3s/tokens/{id}: get: tags: - Token Lookup summary: Get token details description: >- Fetches details of a specific token given its unique identifier. Every token in your network of wallets has a UUID associated with it, regardless of whether it's already recognized or was added as a monitored token. operationId: getTokenId parameters: - $ref: '#/components/parameters/Id' responses: '200': content: application/json: schema: $ref: '#/components/schemas/TokenResponse' description: Token found headers: X-Request-Id: $ref: '#/components/headers/XRequestId' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/NotAuthorized' '404': $ref: '#/components/responses/NotFound' security: - BearerAuth: [] components: parameters: Id: name: id description: The universally unique identifier of the resource. in: path required: true schema: type: string format: uuid example: b3d9d2d5-4c12-4946-a09d-953e82fae2b0 schemas: TokenResponse: title: TokenResponse type: object properties: data: type: object properties: token: $ref: '#/components/schemas/Token' Token: title: Token type: object required: - id - blockchain - isNative - createDate - updateDate properties: id: $ref: '#/components/schemas/Id' name: type: string description: Blockchain name of the specified token. standard: $ref: '#/components/schemas/TokenStandard' blockchain: $ref: '#/components/schemas/Blockchain' decimals: type: integer description: Number of decimal places shown in the token amount. isNative: type: boolean description: >- Defines if the token is a native token of the specified blockchain. If TRUE, the token is a native token. symbol: type: string description: Blockchain symbol of the specified token. tokenAddress: $ref: '#/components/schemas/Address' updateDate: $ref: '#/components/schemas/UpdateDate' createDate: $ref: '#/components/schemas/CreateDate' XRequestId: type: string format: uuid description: >- A unique identifier, which can be helpful for identifying a request when communicating with Circle support. example: 2adba88e-9d63-44bc-b975-9b6ae3440dde Id: type: string format: uuid description: System-generated unique identifier of the resource. example: c4d1da72-111e-4d52-bdbf-2e74a2d803d5 TokenStandard: title: TokenStandard type: string enum: - ERC20 - ERC721 - ERC1155 - Fungible - FungibleAsset - NonFungible - NonFungibleEdition - ProgrammableNonFungible - ProgrammableNonFungibleEdition Blockchain: type: string description: >- The blockchain network that the resource is to be created on or is currently on. enum: - ETH - ETH-SEPOLIA - AVAX - AVAX-FUJI - MATIC - MATIC-AMOY - SOL - SOL-DEVNET - ARB - ARB-SEPOLIA - NEAR - NEAR-TESTNET - EVM - EVM-TESTNET - UNI - UNI-SEPOLIA - BASE - BASE-SEPOLIA - OP - OP-SEPOLIA - APTOS - APTOS-TESTNET - ARC - ARC-TESTNET - MONAD - MONAD-TESTNET example: MATIC-AMOY Address: title: Address description: > Blockchain generated unique identifier, associated with wallet (account), smart contract or other blockchain objects. type: string example: '0xca9142d0b9804ef5e239d3bc1c7aa0d1c74e7350' UpdateDate: type: string format: date-time description: Date and time the resource was last updated, in ISO-8601 UTC format. example: '2023-01-01T12:04:05Z' CreateDate: type: string format: date-time description: Date and time the resource was created, in ISO-8601 UTC format. example: '2023-01-01T12:04:05Z' headers: XRequestId: description: > Developer-provided header parameter or Circle-generated universally unique identifier (UUID v4). Useful for identifying a specific request when communicating with Circle Support. schema: $ref: '#/components/schemas/XRequestId' responses: BadRequest: content: application/json: schema: type: object title: BadRequestResponse required: - code - message properties: code: type: integer description: Code that corresponds to the error. message: type: string description: Message that describes the error. example: code: 400 message: Bad request. description: Request cannot be processed due to a client error. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' NotAuthorized: content: application/json: schema: type: object title: NotAuthorizedResponse required: - code - message properties: code: type: integer description: Code that corresponds to the error. message: type: string description: Message that describes the error. example: code: 401 message: Malformed authorization. description: >- Request has not been applied because it lacks valid authentication credentials. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' NotFound: content: application/json: schema: type: object title: NotFoundResponse required: - code - message properties: code: type: integer description: Code that corresponds to the error. message: type: string description: Message that describes the error. example: code: 404 message: Not found. description: Specified resource was not found. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' securitySchemes: BearerAuth: type: http scheme: bearer bearerFormat: PREFIX:ID:SECRET description: >- Circle's API Keys are formatted in the following structure "PREFIX:ID:SECRET". All three parts are required to make a successful request. ````