## Architecture overview

**eSAW One-Shot** uses two platforms in sequence:

1. **Uanataca** (ModernPKI API) — Creates the certificate request and returns an **esaw_token**. This token identifies the signer and the pending single-use certificate issuance.
2. **eSignAnywhere (eSAW)** — Handles **file upload** and **envelope** creation and sending. The envelope is configured to use the One-Shot signing plugin and the **esaw_token** from step 1, so that when the user signs in eSAW, the signature is created with the Uanataca One-Shot certificate.


Your application orchestrates the flow: call Uanataca to create the request, then call eSAW to upload the document and send the envelope with the token. The end user receives the envelope, opens it in eSAW, and signs using the One-Shot certificate (GenericSigningPluginBit4idOneShot).

## Components

- **Your application** — Calls the Uanataca API (with client certificate) to create the certificate request and obtain `esaw_token`. Then calls the eSAW API (with ApiToken) to upload files and send the envelope, passing `esaw_token` in the envelope's signature plugin data.
- **Uanataca (ModernPKI)** — Issues the single-use certificate when the user completes the signing step in the eSAW envelope. The certificate is created at signing time and used to sign the document.
- **eSignAnywhere** — Hosts the envelope, delivers it to the recipient, and runs the signing UI. The One-Shot plugin uses the `requestToken` (esaw_token) to bind the signature to the Uanataca certificate request.


## Envelope template

A common setup assumes an **envelope template** already created on the eSAW platform with:

- The desired number of signature fields and recipients.
- The **GenericSigningPluginBit4idOneShot** (or equivalent One-Shot GSP) configured for the signature fields.


At send time you fill the template with the document FileId and, in the signing activity, with the **SignaturePluginData** containing `requestToken` set to the `esaw_token` from the Uanataca create-request response.

## Related documentation

- [Signing flow](/products/namirialpkiaas/esaw-one-shot/enterprise-documentation/get-started/signing-flow) — Step-by-step: create request, upload file, send envelope
- [Get started](/products/namirialpkiaas/esaw-one-shot/enterprise-documentation/get-started/get-started) — Endpoint URLs and authentication
- [API reference](/products/namirialpkiaas/esaw-one-shot/enterprise-documentation/developer-documentation/api/api-reference) — Endpoints and OpenAPI spec