> ## 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. # List custody account groups > Retrieves the custody account groups owned by the calling entity. Each row includes an aggregate USD-equivalent balance and a short preview of member account names; use the detail endpoint for metadata only. ## OpenAPI ````yaml openapi/accounts.yaml get /v1/accounts/groups openapi: 3.1.0 info: version: 1.0.0 title: Accounts (Stablecoin) API description: > Circle's Accounts API provides endpoints for managing stablecoin accounts -- including transfers, withdrawals, deposits, wire and ACH bank accounts, and blockchain addresses. An **Account** is a general representation of a ledger or custody object that holds balances. It can be a business account, a stablecoin account ledger for an end user, an extra sub-ledger, or any future custody solution. license: name: Circle License url: https://circle.com/terms servers: - url: https://api-sandbox.circle.com - url: https://api.circle.com security: [] tags: - name: Accounts description: Manage accounts. - name: Account Groups description: Manage custody account groups and their memberships. - name: Limits description: View effective account limits and current usage. - name: Transfers description: > Move funds between accounts or out to a verified blockchain address, and track inbound and outbound onchain transfers. - name: Transactions description: | Get a unified, customer-friendly view of account transaction activity. - name: Wires description: Manage account bank accounts for wire transfers. - name: Deposits description: Get information on account bank deposits. - name: Withdrawals description: Manage account bank withdrawals (fiat offramp). - name: ACH description: Manage account bank accounts for ACH transfers. - name: Deposit Addresses description: Manage account deposit addresses. - name: Recipient Addresses description: Manage account recipient addresses used for transfers. - name: Passkeys description: > Manage WebAuthn passkeys and Strong Customer Authentication (SCA) challenges for end users. - name: Crypto Payments description: > Get crypto payments and crypto refunds received through payment intents. Available for Digital Asset Accounts only on custody accounts (`purpose: custody`), and only for third-party payments. Not supported when the distributor or the end user is under the Circle FR (`CIRCLE_FR`) or Circle SG (`CIRCLE_SG`) legal entity. - name: Crypto Payment Intents description: > Create, expire, refund, and track payment intents for receiving crypto payments. Available for Digital Asset Accounts only on custody accounts (`purpose: custody`), and only for third-party payments. Not supported when the distributor or the end user is under the Circle FR (`CIRCLE_FR`) or Circle SG (`CIRCLE_SG`) legal entity. - name: Crypto Payouts description: > Create and track crypto payouts to recipient addresses. Available for Digital Asset Accounts only on custody accounts (`purpose: custody`), and only for third-party payouts. Not supported when the distributor or the end user is under the Circle FR (`CIRCLE_FR`) or Circle SG (`CIRCLE_SG`) legal entity. - name: Crypto Address Book description: > Manage address book recipients used as crypto payout destinations. Available for Digital Asset Accounts only on custody accounts (`purpose: custody`), and only for third-party payouts. Not supported when the distributor or the end user is under the Circle FR (`CIRCLE_FR`) or Circle SG (`CIRCLE_SG`) legal entity. - name: FX Trades description: | Quote and execute USDC <> EURC swaps for end users' accounts. - name: FX Settlements description: Get settlements of FX trades. - name: Webhook Subscriptions description: Manage subscriptions to Digital Asset Accounts webhook notifications. - name: Webhooks description: | Webhook event payloads Circle sends to a subscribed endpoint. paths: /v1/accounts/groups: get: tags: - Account Groups summary: List custody account groups description: | Retrieves the custody account groups owned by the calling entity. Each row includes an aggregate USD-equivalent balance and a short preview of member account names; use the detail endpoint for metadata only. operationId: listAccountGroups parameters: - $ref: '#/components/parameters/PageBefore' - $ref: '#/components/parameters/PageAfter' - $ref: '#/components/parameters/PageSize' responses: '200': description: Successfully retrieved a list of custody account groups. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' content: application/json: schema: $ref: '#/components/schemas/ListAccountGroupsResponse' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/NotAuthorized' '500': $ref: '#/components/responses/InternalServerError' security: - bearerAuth: [] components: parameters: PageBefore: name: pageBefore description: >- A collection ID value used for pagination. It marks the exclusive end of a page. When provided, the collection resource will return the next `n` items before the id, with `n` being specified by `pageSize`. in: query required: false schema: type: string example: def9520a-5280-4089-9b02-3c9ef8fc8514 PageAfter: name: pageAfter description: >- A collection ID value used for pagination. It marks the exclusive beginning of a page. When provided, the collection resource will return the next `n` items after the id, with `n` being specified by `pageSize`. in: query required: false schema: type: string example: bce1e961-bdb8-4983-a9c2-0b3fbc2614cf PageSize: name: pageSize description: > Limits the number of items to be returned. Some collections have a strict upper bound that will disregard this value. In case the specified value is higher than the allowed limit, the collection limit will be used. If omitted, the collection will determine the page size itself. in: query required: false schema: type: integer minimum: 1 example: 5 headers: XRequestId: description: > Circle-generated universally unique identifier (UUID v4). Useful for identifying a specific request when communicating with Circle Support. schema: $ref: '#/components/schemas/XRequestId' schemas: ListAccountGroupsResponse: title: ListAccountGroupsResponse properties: data: type: array items: $ref: '#/components/schemas/CustodyAccountGroup' XRequestId: type: string format: uuid example: 2adba88e-9d63-44bc-b975-9b6ae3440dde CustodyAccountGroup: type: object description: > A customer-defined grouping of custody accounts owned by a single entity. Each account can belong to at most one group at a time. The `approximateBalanceInUsd` and `accountsPreview` fields are aggregate views populated by the list-groups endpoint. The single-group detail endpoint returns the metadata-only view and omits both fields. required: - id - name - createDate - updateDate properties: id: type: string format: uuid description: Identifier of the custody account group. example: 9c0f1c0d-6c61-4f3d-9b8a-1a3a4b3c5d6e name: type: string description: Display name. maxLength: 32 example: Team A approximateBalanceInUsd: description: > Aggregate USD-equivalent balance across every account in the group. Returned by the list endpoint only. allOf: - $ref: '#/components/schemas/FiatMoneyUsd' accountsPreview: description: > Lightweight summary of member accounts (total count + a few names). Returned by the list endpoint only. allOf: - $ref: '#/components/schemas/AccountsPreview' createDate: description: Timestamp the group was created. allOf: - $ref: '#/components/schemas/UtcTimestamp' updateDate: description: Timestamp the group was last updated. allOf: - $ref: '#/components/schemas/UtcTimestamp' Error: type: object required: - code - message properties: code: type: integer description: > Circle internal status code from the platform `CoreStatusCode` enum (and its domain-specific extensions). **This is not the HTTP status code** — `-1` is the catch-all unknown error, `1`/`2` indicate API parameter problems, `3` is forbidden, `4` is unauthorized, and larger values identify domain-specific failures. Consumers should rely on the HTTP status line for transport-level error class and on this field for the specific Circle error case. example: 2 message: type: string description: >- Internal error message; suitable for logging but not for end-user display. example: API parameter invalid. externalMessage: type: string description: > End-user-displayable error message. Present when the server has generated a customer-facing variant for this error; omitted otherwise. example: The provided amount exceeds the maximum allowed. errors: type: array description: Additional request-field validation errors, when available. items: $ref: '#/components/schemas/ErrorDetail' FiatMoneyUsd: type: object required: - amount - currency properties: amount: type: string description: Magnitude of the amount, in units of the currency, with a `.`. example: '3.14' currency: description: Currency code. type: string enum: - USD AccountsPreview: type: object description: > Lightweight preview of the accounts assigned to a custody account group. Used by the list-groups endpoint to render an at-a-glance summary without requiring the caller to also page through `/v1/accounts`. required: - totalCount - accountNames properties: totalCount: type: integer description: Total number of accounts assigned to the group. example: 15 accountNames: type: array description: > Sample of member account descriptions, ordered alphabetically and truncated to a small preview size. May be shorter than `totalCount`. items: type: string example: - Operations US - Reserve US - Treasury APAC - Treasury EU - Treasury US UtcTimestamp: type: string description: ISO-8601 UTC date/time format. example: '2020-04-10T02:13:30.000Z' ErrorDetail: type: object required: - error - message properties: error: type: string description: Machine-readable error identifier. example: invalid_value location: type: string description: Query parameter or request field that caused the error. example: assetType message: type: string description: Human-readable description of the specific error. example: The operation and assetType combination is invalid. responses: BadRequest: description: The request cannot be processed due to a client error. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' content: application/json: schema: $ref: '#/components/schemas/Error' example: code: 2 message: API parameter invalid. NotAuthorized: description: >- The request has not been applied because it lacks valid authentication credentials. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' content: application/json: schema: $ref: '#/components/schemas/Error' example: code: 4 message: Unauthorized. InternalServerError: description: >- The server encountered an unexpected condition that prevented it from fulfilling the request. headers: X-Request-Id: $ref: '#/components/headers/XRequestId' content: application/json: schema: $ref: '#/components/schemas/Error' example: code: -1 message: 'Something went wrong. errId: 1f0b0c455e40f753f07b4f0ae6abd4b4' securitySchemes: bearerAuth: type: http scheme: bearer ````