> ## 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.

# How-to: Upload documents

> Upload, list, and manage supporting documents for onboarding applications

<Note>
  The End User Onboarding API base URL is `https://api-sandbox.circle.com` for
  sandbox and `https://api.circle.com` for production. All requests require a
  Bearer token obtained via Circle key exchange in the `Authorization` header. All
  `POST` requests require an `X-Idempotency-Key` header with a client-generated
  UUID v4.
</Note>

Attach supporting files to an onboarding application (such as identity
documents, certificates, or proof of address), then list, download, or delete
them while the application is still in a mutable state.

## Prerequisites

Before you begin, ensure that you've:

* Obtained an API key for the End User Onboarding API from the
  [Circle Mint Console](https://console.circle.com).
* Confirmed your application is in `DRAFT` or `PENDING_CUSTOMER_INFORMATION`
  status.
* Identified which `datumName` fields need files (from the schema).

## Steps

### Step 1. Upload a document

Upload a file and link it to a field in the application:

```shell theme={null}
curl --request POST \
  --url https://api-sandbox.circle.com/v1/onboarding/partner/applications/${APPLICATION_ID}/documents \
  --header "Authorization: Bearer ${YOUR_API_KEY}" \
  --header 'X-Idempotency-Key: ${IDEMPOTENCY_KEY}' \
  --form 'fileContent=@passport.pdf' \
  --form 'fileName=passport.pdf' \
  --form 'datumName=authorizedRepGovernmentId' \
  --form 'issuedCountry=US' \
  --form 'documentType=passport'
```

#### Required fields

| Field | Description |
| - | - |
| `fileContent` | Binary file content |
| `fileName` | Filename with extension (for example, `Ownership Chart (1).pdf` or `Company, LLC.pdf`). See [Document file rules](/end-user-onboarding/references/document-file-rules). |
| `datumName` | Schema field name this file satisfies (for example, `authorizedRepGovernmentId`) |

#### Conditionally required fields

| Field | Description |
| - | - |
| `refId` | UUID of the entity this file belongs to. Required for [array sections](/end-user-onboarding/concepts/array-sections). |
| `issuedCountry` | ISO 3166-1 alpha-2 country code. Required for identity documents. |
| `documentType` | Form of identity document being uploaded. Required when the schema field includes an `x-documentTypes` extension. Standard government ID fields accept `passport`, `usdl` (United States driver's license), or `usid` (United States state ID). Notarized government ID fields accept `idNotarization`. |

<Tip>
  To find which `documentType` values are accepted for a given field, retrieve the
  application schema
  (`GET /v1/onboarding/partner/applications/{applicationId}/schema`) and inspect
  the `x-documentTypes` array on the target field. Fields without
  `x-documentTypes` don't require this parameter. For filename characters, size
  limits, and accepted file types, see
  [Document file rules](/end-user-onboarding/references/document-file-rules).
</Tip>

Uploads for array entities need one more step after this request completes.

<Note>
  Uploading a document for an array entity returns a `documentId`, but it does not
  complete the entity's document field by itself. Save the array section again
  with the returned `documentId` in the relevant field, including the same `refId`
  so the API updates the existing entity instead of creating a duplicate. See
  [Array sections](/end-user-onboarding/concepts/array-sections) for an example.
</Note>

**Example response:**

```json theme={null}
{
  "data": {
    "documentId": "550e8400-e29b-41d4-a716-446655440002"
  }
}
```

Uploading to a submitted application returns a `409` error. The application must
be in `DRAFT` or `PENDING_CUSTOMER_INFORMATION`.

### Step 2. List all documents

List all files for an application:

```shell theme={null}
curl --request GET \
  --url https://api-sandbox.circle.com/v1/onboarding/partner/applications/${APPLICATION_ID}/documents \
  --header "Authorization: Bearer ${YOUR_API_KEY}"
```

**Example response:**

```json theme={null}
{
  "data": {
    "documents": [
      {
        "documentId": "550e8400-e29b-41d4-a716-446655440002",
        "fileName": "passport.pdf",
        "datumName": "passport_document",
        "uploadedAt": "2026-03-25T14:30:00Z"
      }
    ]
  }
}
```

### Step 3. Download a document

Download a file you uploaded:

```shell theme={null}
curl --request GET \
  --url https://api-sandbox.circle.com/v1/onboarding/partner/applications/${APPLICATION_ID}/documents/${DOCUMENT_ID} \
  --header "Authorization: Bearer ${YOUR_API_KEY}" \
  --output document.pdf
```

The response body is binary data with a `Content-Type: application/octet-stream`
header.

### Step 4. Delete a document

Delete a document that is no longer needed:

```shell theme={null}
curl --request DELETE \
  --url https://api-sandbox.circle.com/v1/onboarding/partner/applications/${APPLICATION_ID}/documents/${DOCUMENT_ID} \
  --header "Authorization: Bearer ${YOUR_API_KEY}"
```

A successful deletion returns `204 No Content`.

<Warning>
  You can only delete documents while the application is in `DRAFT` or
  `PENDING_CUSTOMER_INFORMATION` status. Deleting a document from a submitted
  application returns a `409` error.
</Warning>

## See also

* [Create and populate applications](/end-user-onboarding/howtos/create-and-populate-applications)
* [Submit and track applications](/end-user-onboarding/howtos/submit-and-track-applications)
* [Array sections](/end-user-onboarding/concepts/array-sections) (for `refId`
  usage)