> ## Documentation Index > Fetch the complete documentation index at: https://docs.apollodeploy.com/llms.txt > Use this file to discover all available pages before exploring further. # Test webhook > Sends a synthetic test event to the webhook endpoint and returns the delivery result. Use this to verify the endpoint is reachable and that your server can parse and verify the Signal webhook signature before going live. ### Requirements - **Permission:** `webhooks:write`. - **Project access:** the path project must match the API key's project. - **HTTP rate limit:** 60 requests per 60 seconds per API key. ## OpenAPI ````yaml /signal/api-reference/openapi.json post /v1/projects/{projectId}/webhooks/{endpointId}/test openapi: 3.1.0 info: title: Apollo Signal API version: 1.0.0 description: >- Public REST API for transactional email, contacts, audiences, webhooks, metrics, projects, and sending domains. servers: - url: https://api.signal.apollodeploy.com description: Production security: [] tags: - name: Emails description: Send, inspect, cancel, validate, and stream transactional email activity. - name: Metrics description: Read project, topic, message, and deliverability analytics. - name: Suppressions description: Manage addresses that Apollo Signal must not send to. - name: Segments description: Create dynamic contact groups and inspect their membership. - name: Topics description: Manage subscription topics and topic membership. - name: Contact properties description: Define the custom fields available on project contacts. - name: Contacts description: >- Manage contacts, audience membership, images, activity, and engagement data. - name: Webhooks description: Manage webhook endpoints, deliveries, tests, and replays. - name: API key usage description: Inspect API key metadata and request usage without exposing raw keys. - name: Projects description: Inspect projects and project-scoped email logs. - name: Sending domains description: >- Register, verify, inspect, and remove sending domains and BIMI configuration. paths: /v1/projects/{projectId}/webhooks/{endpointId}/test: post: tags: - Webhooks summary: Test webhook description: >- Sends a synthetic test event to the webhook endpoint and returns the delivery result. Use this to verify the endpoint is reachable and that your server can parse and verify the Signal webhook signature before going live. ### Requirements - **Permission:** `webhooks:write`. - **Project access:** the path project must match the API key's project. - **HTTP rate limit:** 60 requests per 60 seconds per API key. operationId: testWebhook parameters: - name: projectId in: path description: The project the webhook belongs to. required: true deprecated: false explode: false schema: type: string title: String - name: endpointId in: path description: The unique identifier of the webhook endpoint to test. required: true deprecated: false explode: false schema: type: string title: String responses: '202': description: Test event dispatched. Returns the delivery attempt record. headers: {} content: application/json: schema: $ref: >- #/components/schemas/com.apollodeploy.signal.feature.webhook.api.model.WebhookDeliveryResponse '401': description: Missing or invalid credentials. headers: {} content: application/problem+json: schema: $ref: >- #/components/schemas/com.apollodeploy.commons.core.error.ApiProblem '403': description: >- The credential lacks the required permission or cannot access this project. headers: {} content: application/problem+json: schema: $ref: >- #/components/schemas/com.apollodeploy.commons.core.error.ApiProblem '404': description: Webhook or project not found. headers: {} content: application/problem+json: schema: $ref: >- #/components/schemas/com.apollodeploy.commons.core.error.ApiProblem '429': description: >- The endpoint rate limit was exceeded. Wait for the `Retry-After` interval before retrying. headers: Retry-After: description: Whole seconds to wait before retrying. schema: type: integer minimum: 1 content: application/problem+json: schema: $ref: >- #/components/schemas/com.apollodeploy.commons.core.error.ApiProblem deprecated: false security: - bearerAuth: [] x-codeSamples: - lang: TypeScript label: TypeScript source: >- import { createApolloSignalApiClient } from "@apollo-deploy/signal-sdk"; const signal = createApolloSignalApiClient({ apiKey: "ap_signal_..." }); const result = await signal.webhooks.testWebhook(/* params */); console.log(result); - lang: Python label: Python source: |- from apollo_signal import SignalClient signal = SignalClient(api_key="ap_signal_...") result = signal.webhooks.testWebhook(# params) print(result) - lang: Go label: Go source: >- import signal "github.com/apollo-deploy/signal-sdk-go" client := signal.NewClient("ap_signal_...") result, err := client.Webhooks.TestWebhook(context.Background() /* params */) if err != nil { log.Fatal(err) } fmt.Println(result) - lang: Java label: Java source: |- import com.apollodeploy.signal.SignalClient; SignalClient signal = new SignalClient("ap_signal_..."); var result = signal.webhooks().testWebhook(/* params */); System.out.println(result); - lang: Kotlin label: Kotlin source: |- import com.apollodeploy.signal.SignalClient val signal = SignalClient("ap_signal_...") val result = signal.webhooks.testWebhook(/* params */) println(result) - lang: Ruby label: Ruby source: |- require "apollo_signal" signal = ApolloSignal::Client.new(api_key: "ap_signal_...") result = signal.webhooks.testWebhook(# params) puts result - lang: PHP label: PHP source: |- use ApolloSignal\SignalClient; $signal = new SignalClient("ap_signal_..."); $result = $signal->webhooks->testWebhook(/* params */); var_dump($result); - lang: Rust label: Rust source: |- use apollo_signal::SignalClient; let signal = SignalClient::new("ap_signal_..."); let result = signal.webhooks.testWebhook(/* params */).await?; println!("{:?}", result); - lang: C# label: .NET source: |- using ApolloSignal; var signal = new SignalClient("ap_signal_..."); var result = await signal.Webhooks.TestWebhookAsync(/* params */); Console.WriteLine(result); components: schemas: com.apollodeploy.signal.feature.webhook.api.model.WebhookDeliveryResponse: type: object properties: attemptCount: type: integer format: int32 title: Int createdAt: type: string title: String eventType: type: string title: String id: type: string title: String lastError: type: string title: String lastStatusCode: type: integer format: int32 title: Int nextAttemptAt: type: string title: String projectId: type: string title: String responseBodySnippet: type: string title: String status: type: string title: String updatedAt: type: string title: String webhookEndpointId: type: string title: String required: - attemptCount - createdAt - eventType - id - projectId - status - updatedAt - webhookEndpointId title: WebhookDeliveryResponse com.apollodeploy.commons.core.error.ApiProblem: type: object properties: code: type: string title: ErrorCode detail: type: string title: String errors: type: array items: $ref: >- #/components/schemas/com.apollodeploy.commons.core.error.FieldProblem title: List instance: type: string title: ProblemInstance requestId: type: string title: String status: type: integer format: int32 title: Int title: type: string title: String type: type: string title: ProblemType required: - code - status - title - type title: ApiProblem com.apollodeploy.commons.core.error.FieldProblem: type: object properties: detail: type: string title: String pointer: type: string title: String required: - detail - pointer title: FieldProblem securitySchemes: bearerAuth: type: http scheme: bearer description: >- Project-bound Apollo Signal API key. Keys begin with `ap_signal_` and must carry the permission shown on the operation. ````