> ## 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.
# Release notes - Partner Onboarding - 2026
> 2026 release notes for the Partner Onboarding API
## September 2026
Added a how-to for device risk signals on Stablecoin KYB. Install
[`@circle-fin/device-checks`](https://www.npmjs.com/package/@circle-fin/device-checks)
and call `checkDevice` in the browser before submit or RFI resubmit. The SDK is
web only. Circle records the result and looks it up on submit. Use `code`
`181110`, `181111`, or `181108` to read the outcome.
### Documentation updates
The following documentation was updated:
* [How-to: Collect device risk signals](/end-user-onboarding/howtos/collect-device-risk-signals)
* [How-to: Submit and track applications](/end-user-onboarding/howtos/submit-and-track-applications)
* [How-to: Handle requests for information](/end-user-onboarding/howtos/handle-rfis)
* [Quickstart: Submit onboarding application](/end-user-onboarding/quickstarts/submit-onboarding-application)
* [End User Onboarding API error codes](/api-reference/end-user-onboarding/error-codes)
Published the End User Onboarding error codes catalog for Partner API codes
`181100`-`181111`. The public `message` is the generic HTTP phrase. Use `code`
to tell apart statuses that share a phrase, such as `404` (`181103` vs `181110`)
and `504` (`181109` vs `181111`).
### Documentation updates
The following documentation was updated:
* [End User Onboarding API error codes](/api-reference/end-user-onboarding/error-codes)
* [API errors](/api-reference/errors)
## June 2026
Added a certifications endpoint that returns the compliance certifications
associated with an application, and a `certificationIds` field on the submit
request for GUI integrations where end users explicitly agree to certification
terms.
### API additions
Added the following endpoint to the Partner Onboarding API:
* [`GET /v1/onboarding/partner/applications/{applicationId}/certifications`](/api-reference/end-user-onboarding/get-certifications)
### API updates
The following endpoint now accepts an optional `certificationIds` field:
* [Submit application](/api-reference/end-user-onboarding/submit-application)
now accepts an optional `certificationIds` array. Pass the UUIDs of every
active certification the end user agreed to. Required only for GUI flows where
certifications are presented to end users; omit for API-only integrations.
### Documentation updates
The following documentation was updated:
* [How-to: Submit and Track Applications](/end-user-onboarding/howtos/submit-and-track-applications)
* [Quickstart: Submit Onboarding Application](/end-user-onboarding/quickstarts/submit-onboarding-application)
Added a bulk read endpoint for retrieving saved application data, an optional
resolved JSON Schema that reflects an application's current data, and a
`fieldsChanged` flag on section save responses.
### API additions
Added the following endpoint to the Partner Onboarding API:
* [`GET /v1/onboarding/partner/applications/{applicationId}/data`](/api-reference/end-user-onboarding/get-all-data)
The following endpoints gained new optional query parameters:
* [List sections](/api-reference/end-user-onboarding/list-sections) accepts
`includeData=true` to embed each section's current field data in the response.
* [Get application schema](/api-reference/end-user-onboarding/get-application-schema)
accepts `resolved=true` to prune conditional branches that don't apply to the
application's saved data.
### API updates
The following endpoints now return a `fieldsChanged` flag alongside
`sectionsChanged`. The flag is `true` when a conditional change alters the
required fields in an already-active section, signaling that you should re-fetch
the section to discover the updated field set:
* [Save section data](/api-reference/end-user-onboarding/save-section)
* [Bulk save](/api-reference/end-user-onboarding/bulk-save)
### Documentation updates
The following documentation was updated:
* [How-to: Create and populate applications](/end-user-onboarding/howtos/create-and-populate-applications)