## Signing flow overview

A typical **eSAW One-Shot** envelope process has three main steps. It is assumed that an envelope template already exists on the eSAW platform with the required signature fields and recipients.

1. **Create and approve the certificate request** (Uanataca) — Get `req_pk` and **esaw_token**.
2. **Upload the document** to be signed (eSAW) — Get **FileId**.
3. **Create and send the envelope** (eSAW) — Fill the template with the FileId and the **esaw_token** in the signing activity, then send. The user signs with the One-Shot certificate.


## Step 1: Create certificate request

**API:** `POST /api/v1/esawoneshot`
**Host:** Uanataca (e.g. `https://api.sandbox.modernpki.com`)
**Authentication:** Client certificate (e.g. `--cert cert.pem --key key.pem`).

This call creates the certificate request for the signer. The request body must include enough information to identify the requester (e.g. `rao`, `documents`, `request` with profile, registration_authority, user data, id_document_type, etc.). Full argument details are in the [API reference](/products/namirialpkiaas/esaw-one-shot/enterprise-documentation/developer-documentation/api/api-reference).

**Example request (conceptual):**


```json
{
  "rao": { "username": "...", "password": "...", "pin": "..." },
  "documents": { ... },
  "request": {
    "profile": "PFnubeNC",
    "registration_authority": 1012,
    "communication_language": "ES",
    "id_document_type": "IDC",
    "id_document_country": "ES",
    "serial_number": "12976587A",
    "given_name": "John",
    "surname_1": "Smith",
    "surname_2": "Smith",
    "email": "test@test.com",
    "mobile_phone_number": "+34666777888"
  }
}
```

**Example response:**


```json
{
  "status": "ok",
  "req_pk": 113929,
  "esaw_token": "ba4019803aaf2cd0a9755a688c8963901bfef4b942d7d2179e4e1e44c602"
}
```

Use **esaw_token** in Step 3 as `requestToken` in the envelope's signature plugin data.

## Step 2: Upload file

**API:** `POST /Api/v6/file/upload`
**Host:** eSignAnywhere (e.g. `https://demo.esignanywhere.net`)
**Authentication:** Header `ApiToken: <your-token>`.

Upload the document to be signed. Call this endpoint once per document you want to include in the envelope.

**Example:**


```bash
curl -i -X POST \
  https://demo.esignanywhere.net/Api/v6/file/upload \
  -H "ApiToken: 1234fedq" \
  -F 'File=@"path/to/document"'
```

**Example response:**


```json
{
  "FileId": "aa4e3300-c254-4430-ac16-2f2d96090b3a"
}
```

Use this **FileId** in Step 3 in the envelope's `Documents` array.

## Step 3: Create and send envelope

**API:** `POST /Api/v6/envelope/send`
**Host:** eSignAnywhere (e.g. `https://demo.esignanywhere.net`)
**Authentication:** Header `ApiToken: <your-token>`.

Create and send the envelope. In the request:

- Set **Documents** to include the FileId from Step 2 (and `DocumentNumber` as required by the template).
- In the **Sign** activity, set **SignaturePluginData** for the One-Shot plugin (`GenericSigningPluginBit4idOneShot`) with a field `Key: "requestToken"` and **Value: the esaw_token from Step 1**.


This links the envelope signature to the Uanataca certificate request. When the user signs in eSAW, the One-Shot certificate is issued and applied.

**Example (relevant parts):**

- `Documents`: `[{ "FileId": "aa4e3300-c254-4430-ac16-2f2d96090b3a", "DocumentNumber": 1 }]`
- In the Sign activity, `SignatureDataConfiguration.SignaturePluginData`:
  - `PluginId`: `"GenericSigningPluginBit4idOneShot"`
  - `Fields`: `[{ "Key": "requestToken", "Value": "ba4019803aaf2cd0a9755a688c8963901bfef4b942d7d2179e4e1e44c602" }]`


**Example response:**


```json
{
  "EnvelopeId": "bc6752b7-f761-4b88-91f6-5e3112a716a3"
}
```

The envelope is sent to the user; they open it in eSAW and sign with the One-Shot certificate.

## Related documentation

- [Architecture](/products/namirialpkiaas/esaw-one-shot/enterprise-documentation/get-started/architecture) — Uanataca and eSAW roles
- [Get started](/products/namirialpkiaas/esaw-one-shot/enterprise-documentation/get-started/get-started) — Endpoints and authentication
- [API reference](/products/namirialpkiaas/esaw-one-shot/enterprise-documentation/developer-documentation/api/api-reference) — Full endpoint documentation and OpenAPI spec
- [Postman collection](/products/namirialpkiaas/esaw-one-shot/enterprise-documentation/developer-documentation/resources/postman) — Quick testing