A webhook can either be a standard webhook or a flexible webhook. With a standard webhook, the request and response fields are defined by Dialogflow. With a flexible webhook, you define the request and response fields.
Standard webhooks
With standard webhooks, you use Dialogflow-defined request and response messages. The request message provides many details about the session. For example, current active page, recent matched intent, session parameter values, and agent-defined responses are all included.
Standard webhook request
When a
fulfillment
with a webhook is called,
Dialogflow sends an HTTPS POST webhook request to your webhook service.
The body of this request is a WebhookRequest
JSON object
with information about the session.
Some
integrations
populate the WebhookRequest.payload
field with additional information.
For example, the
Dialogflow CX phone gateway integration
provides the end-user caller ID.
See the
WebhookRequest
(V3)
or
WebhookRequest
(V3Beta1)
reference documentation for details.
Standard webhook response
Once your webhook service receives a webhook request, it needs to send a webhook response. The following limitations apply to your response:
- The response must occur within a timeout that you configure when creating the webhook resource, otherwise the request will time out.
- The response must be less than or equal to 64 KiB in size.
See the
WebhookResponse
(V3)
or
WebhookResponse
(V3Beta1)
reference documentation for details.
Standard webhook resource settings
The following describes webhook resource settings for standard webhooks:
Term | Definition |
---|---|
Display name | The name shown in the console for the webhook. |
Webhook timeout | When Dialogflow sends a webhook request to your webhook service, it may timeout while waiting for a response. This setting controls that timeout in seconds. If a timeout occurs, Dialogflow invokes a webhook.error.timeout event. |
Type | Set to Service directory if you are using service directory for private network access, otherwise set to Generic web service. |
Webhook URL | Provide the URL address for your webhook service. |
Subtype | Set to Standard |
Environment-specific webhook | You can provide environment-specific webhooks. |
Authentication | See the authentication section. |
Custom CA certificate | This is used to upload custom CA certificates. |
Flexible webhooks
With flexible webhooks, you define the request HTTP method, request URL parameters, and fields of the request and response messages. The request can only provide selected parameter values, and the response can only provide parameter override values. This limitation is actually beneficial, because it simplifies the interface between the agent and the webhook. There is rarely a need to communicate anything other than session parameter values between an agent and a webhook. It also simplifies your webhook implementation, because the request and response messages only contain what you need, and you can provide unique webhook messages for various scenarios.
Flexible webhook request
When creating the webhook resource for your agent, you can specify the following for webhook requests:
- The HTTP method used for webhook requests sent to your webhook service.
- Session parameter values that Dialogflow should send to your webhook service using the URL.
- If you choose
POST
,PUT
, orPATCH
as the method, you can specify session parameter values that Dialogflow should send to your webhook service through the request JSON body.
To send session parameter values using the request URL or JSON body, use parameter references as you normally would. You do not need to URL-escape the parameter reference, and you do not wrap the reference in quotations. At runtime, Dialogflow will URL-escape the parameter value as needed. A list or composite value will be provided as JSON.
When using a parameter reference in the JSON body, you must wrap the reference in quotations, regardless of the parameter's type. If the parameter is actually a numeric scalar, list, or composite value, Dialogflow will remove the quotes when sending the request at runtime to preserve the parameter's datatype. String scalar types will remained quoted. If a numeric scalar, list, or composite value is referenced within a string value (for example: "This is a number: $session.params.size"), the parameter will be treated as a string ("This is a number: 3").
For example,
you can provide the fruit
and size
session parameter values
to the request URL like this:
https://your-webhook-service.com/handler?f=$session.params.fruit&s=$session.params.size
And, to the request JSON body like this:
{
"fruitParameter": "$session.params.fruit",
"sizeParameter": "$session.params.size"
}
Flexible webhook response
When creating the webhook resource for your agent, you can specify session parameters that Dialogflow should set to specific fields of the webhook response at runtime.
The following limitations apply to your response:
- The response must occur within a timeout that you configure when creating the webhook resource, otherwise the request will time out.
- The response must be less than or equal to 64 KiB in size.
Use the following format to specify a scalar, list, or composite field:
$.fully.qualified.path.to.field
For example, consider the following JSON response:
{
"routes" : [
{
"legs" : [
{
"distance" : {
"text" : "2,064 mi",
"value" : 3321004
}
}
]
}
]
}
To specify the "value" field, use the following:
$.routes[0].legs[0].distance.value
Flexible webhook resource settings
The following describes webhook resource settings for flexible webhooks:
Term | Definition |
---|---|
Display name | The name shown in the console for the webhook. |
Webhook timeout | When Dialogflow sends a webhook request to your webhook service, it may timeout while waiting for a response. This setting controls that timeout in seconds. If a timeout occurs, Dialogflow invokes a webhook.error.timeout event. |
Type | Set to Service directory if you are using service directory for private network access, otherwise set to Generic web service. |
Webhook URL | Provide the URL address for your webhook service, which may include references to session parameters. |
Subtype | Set to Flexible |
Method | Set the HTTP method for the webhook request. |
Request body | Provide the request JSON body as described above. |
Response configuration | Provide the session parameters that should be set to response fields as described above. |
Environment-specific webhook | You can provide environment-specific webhooks. |
Authentication | See the authentication section. |
Custom CA certificate | This is used to upload custom CA certificates. |
Use a predefined custom template
Dialogflow offers predefined custom templates that you can use to integrate flexible webhooks with Salesforce CRM.
Under the Manage tab, click Webhooks and then + Create.
Under Subtype, select Flexible.
Click Configure using predefined template to enable the feature.
In the Integration type drop-down menu, select Salesforce.
In the API name drop-down menu, select an API name. The template automatically fills out the webhook form based on the API name you choose.
You can manually configure the following fields if applicable, based on your parameters:
- Webhook URL
- Method
- Request body JSON
- Response Configuration
The required OAuth fields will be highlighted in the Authentication section.
Click Save to create the webhook.
Webhook service requirements
The following requirements must be met by your webhook service:
- It must handle HTTPS requests. HTTP is not supported. If you host your webhook service on Google Cloud Platform using a Compute or Serverless Computing solution, see the product documentation for serving with HTTPS. For other hosting options, see Get an SSL certificate for your domain.
- Its URL for requests must be publicly accessible, unless it is hosted as a Cloud Function or it is accessed as a Service directory webhook.
- It must handle requests and responses as described in the standard webhook or flexible webhook section.
- If your agent does not integrate with Service Directory private network access, webhook calls are considered outside the service perimeter and are blocked when enabling VPC Service Controls. Limited endpoints are supported by Service Directory; refer to Service Directory for details.
Authentication
It's important to secure your webhook service, so that only you or your Dialogflow agent are authorized to make requests. This is configured when creating a webhook resource. Dialogflow CX supports the following mechanisms for authentication:
Term | Definition |
---|---|
Authentication headers | For webhook settings, you can specify optional HTTP header key-value pairs. If supplied, Dialogflow adds these HTTP headers to webhook requests. It is common to provide a single pair with a key of authorization . The header values support session parameter references and system function parsing like in static response messages. |
Basic auth with username and password | For webhook settings, you can specify optional login username and password values. If supplied, Dialogflow adds an authorization HTTP header to webhook requests. This header is of the form: "authorization: Basic <base 64 encoding of the string username:password>" . |
Third-party OAuth | You can specify the Third-party OAuth configuration so that Dialogflow exchanges an access token from the OAuth provider and adds it in the authorization HTTP header. Only client credential flow is supported. |
Service agent access tokens | You can select access token in Service agent auth to use service agent access tokens for authentication. This can be used to access other Google Cloud APIs. |
Service agent ID tokens | You can select ID token in Service agent auth to use service agent ID tokens for authentication. This can be used to access Cloud Function and Cloud Run services. |
Mutual TLS authentication | See the Mutual TLS authentication documentation. |
HTTPS certificate verification
Dialogflow by default uses Google's default trust store to verify HTTPS certificates. If you intend to use certificates not recognized by Google's default trust store for your HTTPS server, such as self-signed certificates or custom root certificates, please refer to Custom CA certificates.
Environment-specific webhooks
If you are using environments to isolate production systems from development systems (recommended), you can configure your webhooks to be environment-specific. For each webhook resource you define, you can provide unique URL and authentication settings for each environment that you have defined for the agent.
This allows you to safely develop and test your webhook code updates before deploying them to production.
Create or edit webhook resources
Once you have a webhook service running, you need to create a webhook resource in your agent that has connectivity and authentication information. After creation, you can also edit webhook resource settings at any time.
To create or edit a webhook resource:
Console
- Open the Dialogflow CX Console.
- Choose your Google Cloud project.
- Select your agent.
- Select the Manage tab.
- Click Webhooks.
- Click Create or click a webhook resource in the list to edit.
- Enter standard webhook resource settings or flexible webhook resource settings.
- Click Save.
API
To create a webhook resource, see the create
method for the Webhook
type.
To edit a webhook resource (except for environment-specific settings),
see the patch
or update
method for the Webhook
type.
Select a protocol and version for the Webhook reference:
Protocol | V3 | V3beta1 |
---|---|---|
REST | Webhook resource | Webhook resource |
RPC | Webhook interface | Webhook interface |
C++ | WebhooksClient | Not available |
C# | WebhooksClient | Not available |
Go | WebhooksClient | Not available |
Java | WebhooksClient | WebhooksClient |
Node.js | WebhooksClient | WebhooksClient |
PHP | Not available | Not available |
Python | WebhooksClient | WebhooksClient |
Ruby | Not available | Not available |
To edit the environment-specific settings for a webhook,
see the patch
or update
method for the Environment
type.
Select a protocol and version for the Environment reference:
Protocol | V3 | V3beta1 |
---|---|---|
REST | Environment resource | Environment resource |
RPC | Environment interface | Environment interface |
C++ | EnvironmentsClient | Not available |
C# | EnvironmentsClient | Not available |
Go | EnvironmentsClient | Not available |
Java | EnvironmentsClient | EnvironmentsClient |
Node.js | EnvironmentsClient | EnvironmentsClient |
PHP | Not available | Not available |
Python | EnvironmentsClient | EnvironmentsClient |
Ruby | Not available | Not available |
Webhook errors
If your webhook service encounters an error while handling a webhook request, your webhook code should return one of the following HTTP status codes:
400
Bad Request401
Unauthorized403
Forbidden404
Not found500
Server fault503
Service Unavailable
In any of the following error situations, Dialogflow invokes a webhook error or timeout built-in event and continues processing as usual:
- Response timeout exceeded.
- Error status code received.
- Response is invalid.
- Webhook service is unavailable.
In addition, if the webhook service call
was triggered by a detect intent API call,
the queryResult.webhookStatuses
field in the detect intent response
contains the webhook status information.
Using Cloud Functions
Dialogflow integrates with Cloud Functions, so you can easily create a secure, serverless webhook. If you create a function that resides in the same project as your agent, you just need to select Service Agent Auth -> ID Token in the Auth configuration, your agent can then securely call your webhook.
However, there are two situations in which you must manually setup this integration:
- The Dialogflow Service Agent
service account
with the following address must exist for your agent project:
This special service account and the associated key is normally created automatically when you create the first agent for a project. If your agent was created before November 01, 2020, you may trigger creation of this special service account:service-agent-project-number@gcp-sa-dialogflow.iam.gserviceaccount.com
- Create a new agent for the project.
- Execute the following command:
gcloud beta services identity create --service=dialogflow.googleapis.com --project=agent-project-id
- If your webhook function resides in a different project than the agent, you must provide the Cloud Functions Invoker IAM role to the Dialogflow Service Agent service account in your function's project.
- Select Service Agent Auth -> ID Token in the Auth configuration section.
Using containerized webhooks and the Go ezcx framework
If you would like to implement a containerized webhook using Go, see the Go ezcx framework. This framework can simplify many of the steps required when creating a webhook.
Using Cloud Functions with internal only traffic
Cloud Functions set up to accept internal traffic from VPC networks in the same project or the same VPC SC perimeter can be used as a webhook as long as the agent is in the same project or same VPC SC perimeter.
Using Service Directory for private network access
Dialogflow integrates with Service Directory private network access, so it can connect to webhook targets inside your VPC network. This keeps the traffic within the Google Cloud network and enforces IAM and VPC Service Controls.
To set up a webhook targeting a private network:
Follow Service Directory private network configuration to configure your VPC network and Service Directory endpoint.
The Dialogflow Service Agent service account with the following address must exist for your agent project:
Grant the Dialogflow Service Agent service account the following IAM roles:service-agent-project-number@gcp-sa-dialogflow.iam.gserviceaccount.com
servicedirectory.viewer
of the Service Directory projectservicedirectory.pscAuthorizedService
of the network project
Provide Service Directory Service along with the URL and optional authentication information when creating the webhook.
Console
API
See the
serviceDirectory
field for theWebhook
type.Select a protocol and version for the Webhook reference:
Protocol V3 V3beta1 REST Webhook resource Webhook resource RPC Webhook interface Webhook interface C++ WebhooksClient Not available C# WebhooksClient Not available Go WebhooksClient Not available Java WebhooksClient WebhooksClient Node.js WebhooksClient WebhooksClient PHP Not available Not available Python WebhooksClient WebhooksClient Ruby Not available Not available
To troubleshoot issues, you can set up a private uptime check to check that your Service Directory is correctly configured.
Service agent auth
Dialogflow can generate an ID token or access token using Dialogflow service agent.
The token is added in the authorization HTTP header when Dialogflow calls a webhook.
ID token
An ID token can be used to access Cloud Function and Cloud Run services after you grant Invoker role to
service-agent-project-number@gcp-sa-dialogflow.iam.gserviceaccount.com
The audience used to generate the ID token will be the entire webhook URL except any query parameters. If you are using Cloud Run, make sure this URL is supported by the Cloud Run audiences. For example if the webhook URL is
https://myproject.cloudfunctions.net/my-function/method1?query=value
the following URL needs to be in custom audiences.
https://myproject.cloudfunctions.net/my-function/method1
Any webhook can also optionally validate the token using Google client libraries or open source libraries like github.com/googleapis/google-auth-library-nodejs.
Access token
An access token can be used to access other Google Cloud APIs after you grant required roles to
service-agent-project-number@gcp-sa-dialogflow.iam.gserviceaccount.com
Samples and troubleshooting
See the webhook how-to guide.