Dropbox Sign (HelloSign) OAuth API
{'$ref': './markdown/en/tags/oauth-tag-description.md'}
OpenAPI Specification
openapi: 3.0.3
info:
title: Dropbox Sign Account OAuth API
description: Dropbox Sign v3 API
termsOfService: https://www.hellosign.com/terms
contact:
email: apisupport@hellosign.com
license:
name: MIT
url: https://opensource.org/licenses/MIT
version: 3.0.0
servers:
- url: https://api.hellosign.com/v3
security:
- api_key: []
- oauth2:
- account_access
- signature_request_access
- template_access
- team_access
- api_app_access
- basic_account_info
- request_signature
tags:
- name: OAuth
description:
$ref: ./markdown/en/tags/oauth-tag-description.md
paths:
/oauth/token:
post:
tags:
- OAuth
summary: OAuth Token Generate
description: Once you have retrieved the code from the user callback, you will need to exchange it for an access token via a backend call.
operationId: oauthTokenGenerate
requestBody:
required: true
content:
application/json:
schema:
$ref: '#/components/schemas/OAuthTokenGenerateRequest'
examples:
example:
$ref: '#/components/examples/OAuthTokenGenerateRequest'
responses:
'200':
description: successful operation
headers:
X-RateLimit-Limit:
$ref: '#/components/headers/X-RateLimit-Limit'
X-RateLimit-Remaining:
$ref: '#/components/headers/X-RateLimit-Remaining'
X-Ratelimit-Reset:
$ref: '#/components/headers/X-Ratelimit-Reset'
content:
application/json:
schema:
$ref: '#/components/schemas/OAuthTokenResponse'
examples:
example:
$ref: '#/components/examples/OAuthTokenGenerateResponse'
4XX:
description: failed_operation
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
examples:
400_example:
$ref: '#/components/examples/Error400Response'
401_example:
$ref: '#/components/examples/Error401Response'
402_example:
$ref: '#/components/examples/Error402Response'
403_example:
$ref: '#/components/examples/Error403Response'
429_example:
$ref: '#/components/examples/Error429Response'
4XX_example:
$ref: '#/components/examples/Error4XXResponse'
security: []
servers:
- url: https://app.hellosign.com
x-codeSamples:
- lang: PHP
label: PHP
source:
$ref: examples/OauthTokenGenerateExample.php
- lang: C#
label: C#
source:
$ref: examples/OauthTokenGenerateExample.cs
- lang: TypeScript
label: TypeScript
source:
$ref: examples/OauthTokenGenerateExample.ts
- lang: Java
label: Java
source:
$ref: examples/OauthTokenGenerateExample.java
- lang: Ruby
label: Ruby
source:
$ref: examples/OauthTokenGenerateExample.rb
- lang: Python
label: Python
source:
$ref: examples/OauthTokenGenerateExample.py
- lang: cURL
label: cURL
source:
$ref: examples/OauthTokenGenerateExample.sh
x-meta:
seo:
title: Generate OAuth Token | Documentation | Dropbox Sign for Developers
description: The RESTful Dropbox Sign API easily allows you to build custom eSign integrations. To find out how to generate a new OAuth token with the API, click here.
x-hideTryItPanel: true
/oauth/token?refresh:
post:
tags:
- OAuth
summary: OAuth Token Refresh
description: Access tokens are only valid for a given period of time (typically one hour) for security reasons. Whenever acquiring an new access token its TTL is also given (see `expires_in`), along with a refresh token that can be used to acquire a new access token after the current one has expired.
operationId: oauthTokenRefresh
requestBody:
required: true
content:
application/json:
schema:
$ref: '#/components/schemas/OAuthTokenRefreshRequest'
examples:
example:
$ref: '#/components/examples/OAuthTokenRefreshRequest'
responses:
'200':
description: successful operation
headers:
X-RateLimit-Limit:
$ref: '#/components/headers/X-RateLimit-Limit'
X-RateLimit-Remaining:
$ref: '#/components/headers/X-RateLimit-Remaining'
X-Ratelimit-Reset:
$ref: '#/components/headers/X-Ratelimit-Reset'
content:
application/json:
schema:
$ref: '#/components/schemas/OAuthTokenResponse'
examples:
example:
$ref: '#/components/examples/OAuthTokenRefreshResponse'
4XX:
description: failed_operation
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
examples:
400_example:
$ref: '#/components/examples/Error400Response'
401_example:
$ref: '#/components/examples/Error401Response'
402_example:
$ref: '#/components/examples/Error402Response'
403_example:
$ref: '#/components/examples/Error403Response'
429_example:
$ref: '#/components/examples/Error429Response'
4XX_example:
$ref: '#/components/examples/Error4XXResponse'
security: []
servers:
- url: https://app.hellosign.com
x-codeSamples:
- lang: PHP
label: PHP
source:
$ref: examples/OauthTokenRefreshExample.php
- lang: C#
label: C#
source:
$ref: examples/OauthTokenRefreshExample.cs
- lang: TypeScript
label: TypeScript
source:
$ref: examples/OauthTokenRefreshExample.ts
- lang: Java
label: Java
source:
$ref: examples/OauthTokenRefreshExample.java
- lang: Ruby
label: Ruby
source:
$ref: examples/OauthTokenRefreshExample.rb
- lang: Python
label: Python
source:
$ref: examples/OauthTokenRefreshExample.py
- lang: cURL
label: cURL
source:
$ref: examples/OauthTokenRefreshExample.sh
x-meta:
seo:
title: OAuth Token Refresh | Documentation | Dropbox Sign for Developers
description: The RESTful Dropbox Sign API easily allows you to build custom eSign integrations. To find out how to refresh your OAuth token with the API, click here.
x-hideTryItPanel: true
components:
examples:
OAuthTokenRefreshResponse:
summary: Refresh an existing OAuth token
value:
$ref: examples/json/OAuthTokenRefreshResponse.json
OAuthTokenRefreshRequest:
summary: OAuth Token Refresh Example
value:
$ref: examples/json/OAuthTokenRefreshRequest.json
Error403Response:
summary: Error 403 forbidden
value:
$ref: examples/json/Error403Response.json
OAuthTokenGenerateResponse:
summary: Retrieving the OAuth token
value:
$ref: examples/json/OAuthTokenGenerateResponse.json
Error429Response:
summary: Error 429 exceeded_rate
value:
$ref: examples/json/Error429Response.json
Error400Response:
summary: Error 400 bad_request
value:
$ref: examples/json/Error400Response.json
Error402Response:
summary: Error 402 payment_required
value:
$ref: examples/json/Error402Response.json
Error401Response:
summary: Error 401 unauthorized
value:
$ref: examples/json/Error401Response.json
Error4XXResponse:
summary: Error 4XX failed_operation
value:
$ref: examples/json/Error4XXResponse.json
OAuthTokenGenerateRequest:
summary: OAuth Token Generate Example
value:
$ref: examples/json/OAuthTokenGenerateRequest.json
schemas:
OAuthTokenRefreshRequest:
required:
- grant_type
- refresh_token
properties:
grant_type:
description: When refreshing an existing token use `refresh_token`.
type: string
default: refresh_token
refresh_token:
description: The token provided when you got the expired access token.
type: string
client_id:
description: The client ID for your API app. Required for new API apps. To enhance security, we recommend making it required for existing apps in your app settings.
type: string
client_secret:
description: The client secret for your API app. Required for new API apps. To enhance security, we recommend making it required for existing apps in your app settings.
type: string
type: object
OAuthTokenGenerateRequest:
required:
- client_id
- client_secret
- code
- state
- grant_type
properties:
client_id:
description: The client id of the app requesting authorization.
type: string
client_secret:
description: The secret token of your app.
type: string
code:
description: The code passed to your callback when the user granted access.
type: string
grant_type:
description: When generating a new token use `authorization_code`.
type: string
default: authorization_code
state:
description: Same as the state you specified earlier.
type: string
type: object
ErrorResponse:
required:
- error
properties:
error:
$ref: '#/components/schemas/ErrorResponseError'
type: object
OAuthTokenResponse:
properties:
access_token:
type: string
token_type:
type: string
refresh_token:
type: string
expires_in:
description: Number of seconds until the `access_token` expires. Uses epoch time.
type: integer
state:
type: string
nullable: true
type: object
x-internal-class: true
ErrorResponseError:
description: Contains information about an error that occurred.
required:
- error_msg
- error_name
properties:
error_msg:
description: Message describing an error.
type: string
error_path:
description: Path at which an error occurred.
type: string
error_name:
description: Name of the error. See the `x-error-codes` catalog in openapi file for a complete list of possible error codes with detailed information including HTTP status codes, causes, remediation steps, and retry guidance.
type: string
type: object
headers:
X-RateLimit-Limit:
description: The maximum number of requests per hour that you can make.
schema:
type: integer
format: int32
example: 100
X-Ratelimit-Reset:
description: The Unix time at which the rate limit will reset to its maximum.
schema:
type: integer
format: int64
example: 1430170900
X-RateLimit-Remaining:
description: The number of requests remaining in the current rate limit window.
schema:
type: integer
format: int32
example: 99
securitySchemes:
api_key:
type: http
description: 'Your API key can be used to make calls to the Dropbox Sign API. See [Authentication](/api/reference/authentication) for more information.
✅ Supported by Try it console (calls sent in `test_mode` only).'
scheme: basic
oauth2:
type: http
description: 'You can use an Access Token issued through an OAuth flow to send calls to the Dropbox Sign API from your app. The access scopes required by this endpoint are listed in the gray box above. See [Authentication](/api/reference/authentication) for more information.
❌ **Not supported** by Try it console.'
bearerFormat: JWT
scheme: bearer
externalDocs:
description: Legacy API Reference
url: https://app.hellosign.com/api/reference
x-webhooks:
accountCallback:
post:
summary: Account Callbacks
operationId: accountUpdateEventCallback
description:
$ref: ./markdown/en/descriptions/account-callback-description.md
tags:
- Callbacks and Events
x-meta:
seo:
title: Account Callbacks | API Documentation | Dropbox Sign for Developers
description: The Dropbox Sign API allows you to build with a wide range of tools. To find out how to consume Dropbox Sign Events at the account level, click here.
x-fern-audiences:
- events
requestBody:
description: "**Account Callback Payloads --**\n Events that are reported at the Account level through the the *Account callback URL* defined in your [API settings](https://app.hellosign.com/home/myAccount#api). The *Account callback URL* can also be updated by calling [Update Account](/api/reference/operation/accountUpdate) and passing a `callback_url`."
content:
application/json:
schema:
$ref: '#/components/schemas/EventCallbackPayload'
examples:
signature_request_viewed_example:
$ref: '#/components/examples/EventCallbackSignatureRequestViewed'
signature_request_signed_example:
$ref: '#/components/examples/EventCallbackSignatureRequestSigned'
signature_request_signer_removed_example:
$ref: '#/components/examples/EventCallbackSignatureRequestSignerRemoved'
signature_request_downloadable_example:
$ref: '#/components/examples/EventCallbackSignatureRequestDownloadable'
signature_request_sent_example:
$ref: '#/components/examples/EventCallbackSignatureRequestSent'
signature_request_all_signed_example:
$ref: '#/components/examples/EventCallbackSignatureRequestAllSigned'
signature_request_invalid_example:
$ref: '#/components/examples/EventCallbackSignatureRequestInvalid'
signature_request_email_bounce_example:
$ref: '#/components/examples/EventCallbackSignatureRequestEmailBounce'
signature_request_remind_example:
$ref: '#/components/examples/EventCallbackSignatureRequestRemind'
signature_request_incomplete_qes_example:
$ref: '#/components/examples/EventCallbackSignatureRequestIncompleteQes'
signature_request_destroyed_example:
$ref: '#/components/examples/EventCallbackSignatureRequestDestroyed'
signature_request_canceled_example:
$ref: '#/components/examples/EventCallbackSignatureRequestCanceled'
signature_request_declined_example:
$ref: '#/components/examples/EventCallbackSignatureRequestDeclined'
signature_request_expired_example:
$ref: '#/components/examples/EventCallbackSignatureRequestExpired'
signature_request_reassigned_example:
$ref: '#/components/examples/EventCallbackSignatureRequestReassigned'
signature_request_prepared_example:
$ref: '#/components/examples/EventCallbackSignatureRequestPrepared'
account_confirmed_example:
$ref: '#/components/examples/EventCallbackAccountConfirmed'
unknown_error_example:
$ref: '#/components/examples/EventCallbackUnknownError'
file_error_example:
$ref: '#/components/examples/EventCallbackFileError'
template_created_example:
$ref: '#/components/examples/EventCallbackTemplateCreated'
template_error_example:
$ref: '#/components/examples/EventCallbackTemplateError'
sign_url_invalid_example:
$ref: '#/components/examples/EventCallbackSignUrlInvalid'
callback_test_example:
$ref: '#/components/examples/EventCallbackCallbackTest'
responses:
200:
$ref: '#/components/responses/EventCallbackResponse'
appCallback:
post:
summary: App Callbacks
operationId: apiAppCreateEventCallback
description:
$ref: ./markdown/en/descriptions/api-app-callback-description.md
tags:
- Callbacks and Events
x-meta:
seo:
title: App Callbacks | API Documentation | Dropbox Sign for Developers
description: The Dropbox Sign API allows you to build with a wide range of tools. To find out how to consume Dropbox Sign Events at the App level, click here.
x-fern-audiences:
- events
requestBody:
description: '**API App Callback Payloads --**
Events that are reported at the API App level through the *Event callback URL* defined in your [API settings](https://app.hellosign.com/home/myAccount#api) for a specific app. The *Event callback URL* can also be updated by calling [Update API App](/api/reference/operation/apiAppUpdate) and passing a `callback_url`.'
content:
application/json:
schema:
$ref: '#/components/schemas/EventCallbackPayload'
examples:
signature_request_viewed_example:
$ref: '#/components/examples/EventCallbackSignatureRequestViewed'
signature_request_signed_example:
$ref: '#/components/examples/EventCallbackSignatureRequestSigned'
signature_request_signer_removed_example:
$ref: '#/components/examples/EventCallbackSignatureRequestSignerRemoved'
signature_request_downloadable_example:
$ref: '#/components/examples/EventCallbackSignatureRequestDownloadable'
signature_request_sent_example:
$ref: '#/components/examples/EventCallbackSignatureRequestSent'
signature_request_all_signed_example:
$ref: '#/components/examples/EventCallbackSignatureRequestAllSigned'
signature_request_invalid_example:
$ref: '#/components/examples/EventCallbackSignatureRequestInvalid'
signature_request_email_bounce_example:
$ref: '#/components/examples/EventCallbackSignatureRequestEmailBounce'
signature_request_remind_example:
$ref: '#/components/examples/EventCallbackSignatureRequestRemind'
signature_request_incomplete_qes_example:
$ref: '#/components/examples/EventCallbackSignatureRequestIncompleteQes'
signature_request_destroyed_example:
$ref: '#/components/examples/EventCallbackSignatureRequestDestroyed'
signature_request_canceled_example:
$ref: '#/components/examples/EventCallbackSignatureRequestCanceled'
signature_request_declined_example:
$ref: '#/components/examples/EventCallbackSignatureRequestDeclined'
signature_request_expired_example:
$ref: '#/components/examples/EventCallbackSignatureRequestExpired'
signature_request_reassigned_example:
$ref: '#/components/examples/EventCallbackSignatureRequestReassigned'
signature_request_prepared_example:
$ref: '#/components/examples/EventCallbackSignatureRequestPrepared'
account_confirmed_example:
$ref: '#/components/examples/EventCallbackAccountConfirmed'
unknown_error_example:
$ref: '#/components/examples/EventCallbackUnknownError'
file_error_example:
$ref: '#/components/examples/EventCallbackFileError'
template_created_example:
$ref: '#/components/examples/EventCallbackTemplateCreated'
template_error_example:
$ref: '#/components/examples/EventCallbackTemplateError'
sign_url_invalid_example:
$ref: '#/components/examples/EventCallbackSignUrlInvalid'
callback_test_example:
$ref: '#/components/examples/EventCallbackCallbackTest'
responses:
200:
$ref: '#/components/responses/EventCallbackResponse'
x-error-codes:
bad_request:
http_status: 400
summary: The request contained invalid or malformed parameters.
cause: A parameter failed validation, or the request body was malformed.
remediation: Inspect error_msg and error_path, correct the offending parameter, and resend.
retryable: 'no'
unauthorized:
http_status: 401
summary: The credentials supplied are missing or invalid.
cause: Missing, malformed, or invalid API key or OAuth access token.
remediation: Verify the API key or OAuth token and the Authorization header, then retry.
retryable: 'no'
payment_required:
http_status: 402
summary: The account must be credited or upgraded to perform this action.
cause: The action requires a paid plan, additional quota, or API credits.
remediation: Upgrade the plan or add the required credits/quota, then retry.
retryable: 'no'
forbidden:
http_status: 403
summary: The action is not allowed for these credentials or in the current context.
cause: The authenticated account lacks access to the resource or operation.
remediation: Confirm the account has access to the resource and the required permissions.
retryable: 'no'
not_found:
http_status: 404
summary: Nothing matches the requested resource.
cause: The resource id does not exist or is not visible to this account.
remediation: Verify the id and that the resource belongs to the authenticated account.
retryable: 'no'
conflict:
http_status: 409
summary: The request was well-formed but conflicts with the current state.
cause: The target resource is in a state incompatible with the request (e.g. a signature request is still being set up).
remediation: Wait briefly and retry, or listen for a callback event confirming the resource is ready.
retryable: conditional
exceeded_rate:
http_status: 429
summary: Your account's API request rate limit has been exceeded.
cause: Too many requests were sent within the rate-limit window for this request type.
remediation: Pace requests using the X-RateLimit-* response headers and retry after the window resets.
retryable: 'yes'
backoff: Honor X-Ratelimit-Reset (Unix epoch); otherwise exponential backoff with jitter. No Retry-After header is sent.
unknown:
http_status: 500
summary: An unexpected error occurred.
cause: An unhandled server-side error, or a status code without a more specific error_name.
remediation: Retry transient failures; if it persists, contact support with the request details.
retryable: conditional
backoff: For transient 5xx, retry with exponential backoff; otherwise do not retry.
team_invite_failed:
http_status: 403
summary: The team invitation could not be completed.
cause: The invitee already belongs to a team, or the invite is otherwise not permitted.
remediation: Confirm the invitee is not already on a team before inviting.
retryable: 'no'
max_faxes:
http_status: 429
summary: Too many fax transmissions are currently pending or transmitting.
cause: The account has reached the limit of concurrent in-flight fax transmissions.
remediation: Wait for outstanding transmissions to complete, then retry.
retryable: 'yes'
backoff: Retry with exponential backoff once pending transmissions clear.
invalid_recipient:
http_status: 400
summary: The recipient (fax number or email address) is invalid.
cause: A recipient value did not pass validation.
remediation: Correct the recipient value and resend.
retryable: 'no'
signature_request_cancel_failed:
http_status: 400
summary: The signature request could not be cancelled.
cause: The caller is not the requester, or the request is already fully executed/closed.
remediation: Only the requester can cancel, and only before the request is fully executed.
retryable: 'no'
signature_request_remove_failed:
http_status: 400
summary: Access to the signature request could not be removed.
cause: The signature request has not yet been fully executed, so access cannot be revoked.
remediation: Wait until all parties have signed, or call /signature_request/cancel to cancel incomplete requests instead.
retryable: 'no'
maintenance:
http_status: 503
summary: The request could not be completed because the site is under maintenance.
cause: The API is in a scheduled maintenance window.
remediation: Retry once the maintenance window ends.
retryable: 'yes'
backoff: Retry later with exponential backoff.
method_not_supported:
http_status: 405
summary: The HTTP method is not supported for this endpoint.
cause: The request used a verb the endpoint does not accept.
remediation: Use the HTTP method documented for the endpoint.
retryable: 'no'
invalid_reminder:
http_status: 400
summary: The signature request reminder was invalid.
cause: A reminder was attempted against an ineligible request (e.g. embedded, closed, or expired).
remediation: Only send reminders for eligible (non-embedded, open) signature requests.
retryable: 'no'
unavailable:
http_status: 503
summary: The service is temporarily unavailable.
cause: A downstream dependency or the service itself is temporarily unavailable.
remediation: Retry later with exponential backoff.
retryable: 'yes'
backoff: Retry later with exponential backoff and jitter.
unprocessable_entity:
http_status: 422
summary: The request was understood but the target entity cannot be processed.
cause: The resource is still being processed, or it is in an error state.
remediation: If the resource is still processing, wait and retry; if it is in an error state, recreate/resend it instead of retrying.
retryable: conditional
backoff: If still processing, retry with exponential backoff; if in an error state, do not retry.
signature_request_expired:
http_status:
- 400
- 403
summary: The signature request has expired.
cause: The operation targets a request whose expiration has passed. Most endpoints return 400; final-copy/download endpoints return 403.
remediation: The request can no longer be acted upon; create a new signature request.
retryable: 'no'
deleted:
http_status: 410
summary: The request was cancelled or deleted.
cause: The resource has been cancelled or removed and is no longer available.
remediation: Do not retry; the resource is permanently gone.
retryable: 'no'
x-oauth-error-codes:
invalid_grant:
http_status:
- 400
- 401
summary: The OAuth grant (authorization code or refresh token) is invalid or expired.
cause: The code/token was already used, expired, or does not match the client.
remediation: Re-initiate the OAuth flow to obtain a fresh authorization code.
retryable: 'no'
invalid_client:
http_status: 400
summary: The OAuth client credentials are invalid.
cause: The client_id or client_secret is unrecognized or incorrect.
remediation: Verify the client_id and client_secret from the API app settings.
retryable: 'no'
invalid_request:
http_status: 400
summary: The OAuth request is malformed or missing required parameters.
cause: A required parameter is missing, or the request format is invalid.
remediation: Check the request against the OAuth token endpoint documentation.
retryable: 'no'
unauthorized_client:
http_status:
- 401
- 403
summary: The OAuth client is not authorized to perform this action.
cause: The app has not been approved, or the action is outside the granted scopes.
remediation: Ensure the app is approved and the required scopes are granted.
retryable: 'no'
unsupported_grant_type:
http_status: 400
summary: The grant type is not supported.
cause: The grant_type parameter value is not recognized.
remediation: Use authorization_code or refresh_token as the grant_type.
retryable: 'no'
payment_required:
http_status: 402
summary: The account requires a paid plan to use this OAuth app.
cause: The authorizing account does not have a plan that supports this integration.
remediation: Upgrade the account to a plan that includes OAuth app access.
retryable: 'no'
addon_required:
http_status: 402
summary: An add-on is required to use this OAuth app.
cause: The account plan does not include the add-on needed for this integration.
remediation: Add the required add-on to the account subscription.
retryable: 'no'
invalid_scope:
http_status: 400
summary: The requested OAuth scope is invalid.
cause: The scope parameter contains values not permitted for the app.
remediation: Request only scopes that the app is configured to use.
retryable: 'no'
quota_reached:
http_status: 402
summary: The account has reached its usage quota for this OAuth app.
cause: The authorizing account has exhausted its quota for the integration.
remediation: Contact the app owner or upgrade the account quota.
retryable: 'no'
server_error:
http_status: 500
summary: An internal server error occurred during OAuth processing.
cause: An unexpected error on the server side while handling the OAuth request.
remediation: Retry the request; if it persists, contact support.
retryable: 'yes'
backoff: Retry with exponential backoff.
temporary_unavailable:
http_status: 503
summary: The OAuth service is temporarily unavailable.
cause: The service is under maintenance or experiencing temporary issues.
remediation: Retry after a short delay.
retryable: 'yes'
backoff: Retry with exponential backoff.
x-error-events:
signature_request_invalid:
event_type: signature_request_invalid
delivery: webhook
summary: Asynchronous error while processing a signature request.
cause: A signature request could not be processed (e.g. invalid tags, fields, or merge data).
remediation: Inspect event.event_metadata.event_message in the callback, correct the request, and resend.
retryable: conditional
unknown_error:
event_type: unknown_error
delivery: webhook
summary: An unspecified asynchronous processing error occurred.
cause: An unexpected error occurred while processing the request asynchronously.
remediation: Check the request status in the API dashboard; retry or contact support if it persists.
retryable: conditional
file_error:
event_type: file_error
delivery: webhook
summary: Asynchronous error while processing an uploaded file.
cause: A file attached to a request could not be processed.
remediation: Resend the request with a supported, non-corrupt file.
retryable: conditional
template_error:
event_type: template_error
delivery: webhook
summary: Asynchronous error while creating a template.
cause: Template file processing failed (e.g. unsupported or corrupt file).
remediation: Recreate the template with a valid file; check status in the API dashboard.
retryable: conditional
sign_url_invalid:
event_type: sign_url_invalid
delivery: webhook
summary: An embedded signing URL has expired or become invalid.
cause: The embedded sign_url is no longer valid (e.g. expired).
remediation: Generate a fresh embedded sign_url via the embedded sign URL endpoint.
retryable: 'yes'