Integrate WhatsApp

Integrate WhatsApp

Setup

Env vars:

• KAPSO_API_BASE_URL (host only, no /​platform/​v1)
• KAPSO_API_KEY
• META_GRAPH_VERSION (optional, default v24.0)

Auth header (direct API calls):

X-API-Key: <api_key>

Install deps (once):

npm i

Connect WhatsApp (setup links)

Typical onboarding flow:

1. Create customer: POST /​platform/​v1/​customers
2. Generate setup link: POST /​platform/​v1/​customers/:id/​setup_links
3. Customer completes embedded signup
4. Use phone_number_id to send messages and configure webhooks

Detect connection:

• Project webhook whatsapp.phone_number.created (recommended)
• Success redirect URL query params (use for frontend UX)

Provision phone numbers (setup link config):

{
  "setup_link": {
    "provision_phone_number": true,
    "phone_number_country_isos": ["US"]
  }
}

Notes:

• Platform API base: /​platform/​v1
• Meta proxy base: /​meta/​whatsapp/​v24.0 (messaging, templates, media)
• Use phone_number_id as the primary WhatsApp identifier

Receive events (webhooks)

Use webhooks to receive:

• Project events (connection lifecycle, workflow events)
• Phone-number events (messages, conversations, delivery status)

Scope rules:

• Project webhooks: only project-level events (connection lifecycle, workflow events)
• Phone-number webhooks: only WhatsApp message + conversation events for that phone_number_id
• WhatsApp message/​conversation events (whatsapp.message.*, whatsapp.conversation.*) are phone-number only

Create a webhook:

• Project-level: node scripts/​create.js --scope project --url <https://...> --events <csv>
• Phone-number: node scripts/​create.js --phone-number-id <id> --url <https://...> --events <csv>

Common flags for create/​update:

• --url <https://...> - webhook destination
• --events <csv|json-array> - event types (Kapso webhooks)
• --kind <kapso|meta> - Kapso (event-based) vs raw Meta forwarding
• --payload-version <v1|v2> - payload format (v2 recommended)
• --buffer-enabled <true|false> - enable buffering for whatsapp.message.received
• --buffer-window-seconds <n> - 1-60 seconds
• --max-buffer-size <n> - 1-100
• --active <true|false> - enable/​disable

Test delivery:

node scripts/​test.js --webhook-id <id>

Always verify signatures. See:

• references/​webhooks-overview.md
• references/​webhooks-reference.md

Send and read messages

Discover IDs first

Two Meta IDs are needed for different operations:

SDK setup

Install:

npm install @kapso/​whatsapp-cloud-api

Create client:

import { WhatsAppClient } from "@kapso/​whatsapp-cloud-api";

const client = new WhatsAppClient({
  baseUrl: "https://api.kapso.ai/​meta/​whatsapp",
  kapsoApiKey: process.env.KAPSO_API_KEY!
});

Send a text message

Via SDK:

await client.messages.sendText({
  phoneNumberId: "<PHONE_NUMBER_ID>",
  to: "+15551234567",
  body: "Hello from Kapso"
});

Send a template message

1. Discover IDs: node scripts/​list-platform-phone-numbers.mjs
2. Draft template payload from assets/​template-utility-order-status-update.json
3. Create: node scripts/​create-template.mjs --business-account-id <WABA_ID> --file <payload.json>
4. Check status: node scripts/​template-status.mjs --business-account-id <WABA_ID> --name <name>
5. Send: node scripts/​send-template.mjs --phone-number-id <ID> --file <send-payload.json>

Send an interactive message

Interactive messages require an active 24-hour session window. For outbound notifications outside the window, use templates.

1. Discover phone_number_id
2. Pick payload from assets/​send-interactive-*.json
3. Send: node scripts/​send-interactive.mjs --phone-number-id <ID> --file <payload.json>

Read inbox data

Use Meta proxy or SDK:

• Proxy: GET /​{phone_number_id}/​messages, GET /​{phone_number_id}/​conversations
• SDK: client.messages.query(), client.conversations.list()

Template rules

Creation:

• Use parameter_format: "NAMED" with {{param_name}} (preferred over positional)
• Include examples when using variables in HEADER/​BODY
• Use language (not language_code)
• Don't interleave QUICK_REPLY with URL/​PHONE_NUMBER buttons
• URL button variables must be at the end of the URL and use positional {{1}}

Send-time:

• For NAMED templates, include parameter_name in header/​body params
• URL buttons need a button component with sub_type: "url" and index
• Media headers use either id or link (never both)

WhatsApp Flows

Use Flows to build native WhatsApp forms. Read references/​whatsapp-flows-spec.md before editing Flow JSON.

Create and publish a flow

1. Create flow: node scripts/​create-flow.js --phone-number-id <id> --name <name>
2. Update JSON: node scripts/​update-flow-json.js --flow-id <id> --json-file <path>
3. Publish: node scripts/​publish-flow.js --flow-id <id>
4. Test: node scripts/​send-test-flow.js --phone-number-id <id> --flow-id <id> --to <phone>

Attach a data endpoint (dynamic flows)

1. Set up encryption: node scripts/​setup-encryption.js --flow-id <id>
2. Create endpoint: node scripts/​set-data-endpoint.js --flow-id <id> --code-file <path>
3. Deploy: node scripts/​deploy-data-endpoint.js --flow-id <id>
4. Register: node scripts/​register-data-endpoint.js --flow-id <id>

Flow JSON rules

Static flows (no data endpoint):

• Use version: "7.3"
• routing_model and data_api_version are optional
• See assets/​sample-flow.json

Dynamic flows (with data endpoint):

• Use version: "7.3" with data_api_version: "3.0"
• routing_model is required (defines valid screen transitions)
• See assets/​dynamic-flow.json

Data endpoint rules

Handler signature:

async function handler(request, env) {
  const body = await request.json();
  // body.data_exchange.action: INIT | data_exchange | BACK
  // body.data_exchange.screen: current screen id
  // body.data_exchange.data: user inputs
  return Response.json({
    version: "3.0",
    screen: "NEXT_SCREEN_ID",
    data: { }
  });
}

• Do not use export or module.exports
• Completion uses screen: "SUCCESS" with extension_message_response.params
• Do not include endpoint_uri or data_channel_uri (Kapso injects these)

Troubleshooting

• Preview shows "flow_token is missing": flow is dynamic without a data endpoint. Attach one and refresh.
• Encryption setup errors: enable encryption in Settings for the phone number/​WABA.
• OAuthException 139000 (Integrity): WABA must be verified in Meta security center.

Scripts

Webhooks

Messaging and templates

Flows

OpenAPI

Examples:

node scripts/​openapi-explore.mjs --spec whatsapp search "template"
node scripts/​openapi-explore.mjs --spec whatsapp op sendMessage
node scripts/​openapi-explore.mjs --spec whatsapp schema TemplateMessage
node scripts/​openapi-explore.mjs --spec platform ops --tag "WhatsApp Flows"
node scripts/​openapi-explore.mjs --spec platform op setupWhatsappFlowEncryption
node scripts/​openapi-explore.mjs --spec platform search "setup link"

Assets

References

• references/​getting-started.md - Platform onboarding
• references/​platform-api-reference.md - Full endpoint reference
• references/​setup-links.md - Setup link configuration
• references/​detecting-whatsapp-connection.md - Connection detection methods
• references/​webhooks-overview.md - Webhook types, signature verification, retries
• references/​webhooks-event-types.md - Available events
• references/​webhooks-reference.md - Webhook API and payload notes
• references/​templates-reference.md - Template creation rules, components cheat sheet, send-time components
• references/​whatsapp-api-reference.md - Meta proxy payloads for messages and conversations
• references/​whatsapp-cloud-api-js.md - SDK usage for sending and reading messages
• references/​whatsapp-flows-spec.md - Flow JSON spec

Related skills

• automate-whatsapp - Workflows, agents, and automations
• observe-whatsapp - Debugging, logs, health checks

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