# Kapso

> Kapso is the WhatsApp API for developers. It runs on the official Meta WhatsApp Business Platform and adds what Meta leaves to you: onboarding for customer-owned WhatsApp numbers, webhooks with delivery logs, an inbox with human handoff, workflows, WhatsApp Flows, and tooling for AI agents.

## When to use Kapso

Reach for Kapso when the job is one of these:

- Add official WhatsApp messaging to a product: send text, media, templates, buttons, lists, and Flows, and receive replies by webhook.
- Let each of your customers connect their own WhatsApp Business number to your product through a connection link, then message on their behalf.
- Give an AI agent a WhatsApp number so it can read and reply to conversations, with handoff to a human inbox.
- Build or debug webhooks: inspect deliveries, retries, and failed messages.
- Manage templates, phone numbers, contacts, and conversations from a terminal or an MCP client.

Do not use Kapso for:

- WhatsApp automation over a personal account.
- WhatsApp Groups. The Groups API is waitlist only: https://kapso.com/whatsapp-groups
- SMS, email, or channels other than WhatsApp.

## How to call Kapso

A human creates the Kapso project first. Browser sign-in works for any project member on MCP and the CLI. A project API key is only needed for REST and for non-interactive MCP or CLI use.

After that:

- Project MCP (no shell needed): endpoint `https://api.kapso.ai/mcp`. Auth with browser sign-in or `Authorization: Bearer <project_api_key>`.
- OAuth for MCP clients (discovery, PKCE, scopes, refresh, revocation): https://kapso.com/auth.md
- CLI (shell access): `curl -fsSL https://kapso.com/install.sh | bash`, then `kapso setup`.
- REST: host `https://api.kapso.ai`, header `X-API-Key: <project_api_key>`. OpenAPI specs are listed below.
- TypeScript: `npm install @kapso/whatsapp-cloud-api`.
- Coding agents editing a codebase: `npx skills add gokapso/agent-skills`.
- Agent instructions: https://kapso.com/AGENTS.md

## Docs

- [Docs index](https://docs.kapso.ai/llms.txt): every docs page as a link. Each page also serves markdown at its URL plus `.md`.
- [Build with AI](https://docs.kapso.ai/docs/build-with-ai.md): CLI, Project MCP, docs MCP, and agent skills in one page.
- [Project MCP](https://docs.kapso.ai/docs/whatsapp/mcp.md): tools, auth, and client setup.
- [CLI](https://docs.kapso.ai/docs/whatsapp/cli.md): command reference.
- [TypeScript SDK](https://docs.kapso.ai/docs/whatsapp/typescript-sdk/introduction.md): quickstart.
- [Send messages](https://docs.kapso.ai/docs/whatsapp/send-messages/text.md): text, media, templates, interactive.
- [Webhooks](https://docs.kapso.ai/docs/platform/webhooks/overview.md): receive messages and events.
- [Customer onboarding](https://docs.kapso.ai/docs/platform/customer-guide.md): setup links for customer-owned numbers.
- [WhatsApp Flows](https://docs.kapso.ai/docs/whatsapp/flows/overview.md): forms and data endpoints.
- [WhatsApp API OpenAPI](https://docs.kapso.ai/api/meta/whatsapp/openapi-whatsapp.yaml)
- [Platform API OpenAPI](https://docs.kapso.ai/api/platform/v1/openapi-platform.yaml)
- [Workflows API OpenAPI](https://docs.kapso.ai/api/platform/v1/openapi-workflows.yaml)
- [WhatsApp API OpenAPI (JSON)](https://kapso.com/openapi.json)
- [Platform API OpenAPI (JSON)](https://kapso.com/openapi/platform.json)
- [Workflows API OpenAPI (JSON)](https://kapso.com/openapi/workflows.json)

## Product

- [Pricing](https://kapso.com/pricing.md): Free, Pro, and Platform plans. Every plan includes a sandbox number.
- [Platform](https://kapso.com/platform): customer-owned onboarding, connection links, APIs, webhooks, and inbox workflows.
- [WhatsApp API for developers](https://kapso.com/whatsapp-api-for-developers)
- [WhatsApp AI agent](https://kapso.com/whatsapp-ai-agent)
- [Connect customer WhatsApp](https://kapso.com/connect-customer-whatsapp)
- [WhatsApp webhooks](https://kapso.com/whatsapp-webhooks)
- [WhatsApp human handoff](https://kapso.com/whatsapp-human-handoff)
- [WhatsApp MCP server](https://kapso.com/whatsapp-mcp-server)
- [WhatsApp CLI](https://kapso.com/whatsapp-cli)
- [Twilio alternative for WhatsApp](https://kapso.com/twilio-alternative-for-whatsapp)

## Guides

Free written guides on how the WhatsApp Business Platform behaves. Each chapter is its own page.

- [All guides](https://kapso.com/guides)
- [WhatsApp Pricing](https://kapso.com/guides/whatsapp-pricing): What WhatsApp messaging actually costs: how Meta assigns a price to every message, how billing evidence arrives after delivery, and what changes when service messages and utility replies become billable on October 1, 2026.
- [Business-scoped user IDs](https://kapso.com/guides/business-scoped-user-ids): Meta is replacing the phone number as the identity key on the WhatsApp Business Platform. The new identifiers have been arriving in your webhooks since April 2026, and the phone number is only now starting to disappear. This guide covers the whole migration: how to read, store, match and message a business-scoped user ID.

## Canonical facts

- Kapso uses the official Meta WhatsApp Business Platform (Cloud API). It is not an unofficial WhatsApp client.
- Every plan includes a sandbox number for testing without production credentials.
- Plans: Free, Pro, and Platform. Current prices, message volumes, and number limits are on the pricing page.
- Meta's WhatsApp message pricing changes on October 1, 2026. See the WhatsApp pricing guide.
- Kapso supports messages, templates, webhooks, contacts, conversations, customers, customer connection links, phone numbers, broadcasts, workflows, serverless functions, and WhatsApp Flows.
- Treat project API keys, webhook secrets, and production WhatsApp sends as application-controlled credentials and actions. Prefer sandbox numbers and development projects for tests.

## Optional

- [About](https://kapso.com/about), [Contact](https://kapso.com/contact), [Trust & legal](https://kapso.com/trust), [Blog](https://kapso.com/blog)
- Tool pages: [Codex](https://kapso.com/whatsapp-codex), [Claude Code](https://kapso.com/whatsapp-claude-code), [OpenClaw](https://kapso.com/whatsapp-openclaw), [Hermes Agent](https://kapso.com/whatsapp-hermes-agent), [Chat SDK](https://kapso.com/whatsapp-chat-sdk)
- Tool docs: [Chat SDK](https://docs.kapso.ai/docs/whatsapp/chat-sdk.md), [OpenClaw](https://docs.kapso.ai/docs/whatsapp/openclaw.md), [Hermes Agent](https://docs.kapso.ai/docs/whatsapp/hermes-agent.md)
- Spanish: [API de WhatsApp para desarrolladores](https://kapso.com/es/api-whatsapp-para-desarrolladores), [Agentes de IA para WhatsApp](https://kapso.com/es/agentes-ia-whatsapp), [Alternativa a Twilio para WhatsApp](https://kapso.com/es/alternativa-twilio-whatsapp)
- [Full index](https://kapso.com/llms-full.txt), [Markdown sitemap](https://kapso.com/sitemap.md)

## Blog posts
- [Kapso raises $1.4M](https://kapso.com/blog/kapso-seed-round-1-4-million): The journey, who invested, and where we’re going.
- [Launching Kapso-managed billing](https://kapso.com/blog/launching-kapso-managed-billing): Kapso is now a BSP, and developers can now own the full billing experience of their WhatsApp product.
- [WhatsApp message templates for developers](https://kapso.com/blog/whatsapp-message-templates-for-developers): A practical guide to WhatsApp templates: when they are required, how categories affect approval and pricing, how variables work, and what to model in your product.
- [WhatsApp Flows for developers](https://kapso.com/blog/whatsapp-flows-for-developers): A developer guide to WhatsApp Flows: static vs dynamic flows, Flow JSON, data endpoints, encryption, response contracts, and how Kapso reduces the operational work.
- [Cómo funciona WhatsApp Embedded Signup para plataformas SaaS](https://kapso.com/blog/whatsapp-embedded-signup-para-plataformas-saas): Una guía práctica para equipos SaaS que quieren dejar que sus clientes conecten su propia cuenta de WhatsApp Business sin convertir el onboarding en un proyecto de infraestructura.
- [Como o WhatsApp Embedded Signup funciona para plataformas SaaS](https://kapso.com/blog/whatsapp-embedded-signup-para-plataformas-saas-pt): Um guia prático para equipes SaaS que querem permitir que cada cliente conecte sua própria conta do WhatsApp Business sem transformar onboarding em infraestrutura.
- [How WhatsApp embedded signup works for SaaS platforms](https://kapso.com/blog/whatsapp-embedded-signup-for-saas-platforms): A practical guide to WhatsApp embedded signup for SaaS teams that want customers to connect their own WhatsApp Business accounts without turning onboarding into infrastructure.
- [WhatsApp Business App coexistence with Cloud API](https://kapso.com/blog/whatsapp-business-app-coexistence-cloud-api): A practical guide to WhatsApp Business App coexistence: when it helps, when it hurts, how the QR onboarding path works, and what SaaS teams should promise customers.
- [WhatsApp API pricing in 2026](https://kapso.com/blog/whatsapp-api-pricing-2026): A detailed but readable guide to WhatsApp API pricing: Meta fees, platform fees, template pricing updates, service windows, and how to compare Kapso with Twilio-style providers.
- [Twilio vs Kapso for WhatsApp pricing: a developer benchmark](https://kapso.com/blog/twilio-vs-kapso-whatsapp-pricing-benchmark): A concise benchmark comparing Twilio and Kapso pricing for common WhatsApp API message volumes, with implementation questions developers should ask before switching.
- [The state of the WhatsApp Groups API in 2026: available, but mostly blocked by OBA](https://kapso.com/blog/whatsapp-groups-api-state-2026): WhatsApp Groups API exists, but OBA eligibility and product limits make it unusable for most teams. Here is what the API can do and when to build on it.
- [WhatsApp Business accounts are changing: WAACs, Messaging Accounts, and paid_messaging_account_id](https://kapso.com/blog/whatsapp-business-account-changes-2026): Meta is splitting WhatsApp Business accounts into WAACs and Messaging Accounts. Here is what changes, when paid_messaging_account_id matters, and how to prepare.
- [WhatsApp BSUIDs and usernames: what developers need to change in 2026](https://kapso.com/blog/whatsapp-bsuid-usernames-2026): WhatsApp usernames are changing identity on the Business Platform. Learn how BSUIDs affect webhooks, nullable phone numbers, matching, and Kapso integrations.
- [WhatsApp's 24-hour customer service window, explained for developers](https://kapso.com/blog/whatsapp-24-hour-rule-service-window): A practical developer guide to WhatsApp's 24-hour customer service window: when free-form replies are allowed, when templates are required, and how to model it.
- [Kapso is an official Chat SDK Adapter](https://kapso.com/blog/chat-sdk-adapter): Kapso’s Chat SDK adapter lets developers build WhatsApp agents with one TypeScript handler, signed Kapso webhooks, native buttons, media attachments, reactions, outbound DMs, and Kapso-backed conversation history.
- [10,000 developers](https://kapso.com/blog/10k-developers): Two months ago, we hit 5,000 developers. Today, Kapso just crossed 10,000.
- [Product updates Feb 12, 2026](https://kapso.com/blog/product-updates-feb-12): Kapso Playbooks, GPT-5.2, and more control over WhatsApp workflows
- [5,000 developers](https://kapso.com/blog/5000-developers): I'm excited to share that Kapso just reached 5,000 developers from all over the world.

# Kapso sitemap

## Public pages
- [Kapso](https://kapso.com/): WhatsApp for developers.
- [Pricing](https://kapso.com/pricing): Simple WhatsApp API pricing for developers and platforms.
- [About Kapso](https://kapso.com/about): Developer-first infrastructure for the official WhatsApp Business Platform.
- [Contact Kapso](https://kapso.com/contact): Contact Kapso about product, technical, security, privacy, or partnerships.
- [Trust & Legal](https://kapso.com/trust): Kapso's legal and privacy documents.
- [Platform](https://kapso.com/platform): Customer-owned WhatsApp onboarding, connection links, APIs, webhooks, and inbox workflows.
- [WhatsApp AI Agent](https://kapso.com/whatsapp-ai-agent): Build WhatsApp AI agents with the official API, webhooks, MCP, workflows, and human handoff.
- [WhatsApp Webhooks](https://kapso.com/whatsapp-webhooks): Receive WhatsApp messages, delivery statuses, conversation events, and workflow handoffs with Kapso webhooks.
- [WhatsApp API for Developers](https://kapso.com/whatsapp-api-for-developers): Send and receive WhatsApp messages with Kapso APIs, webhooks, CLI, MCP, templates, and workflows.
- [Connect Customer WhatsApp](https://kapso.com/connect-customer-whatsapp): Let each customer connect their own WhatsApp Business account with connection links, platform APIs, webhooks, and inbox workflows.
- [WhatsApp MCP Server](https://kapso.com/whatsapp-mcp-server): Use Kapso WhatsApp MCP to let AI agents operate WhatsApp numbers, messages, conversations, templates, webhooks, and customer-owned accounts.
- [WhatsApp CLI](https://kapso.com/whatsapp-cli): Manage WhatsApp numbers, messages, templates, webhooks, customer onboarding, and workflows from the terminal with the Kapso CLI.
- [WhatsApp Chat SDK](https://kapso.com/whatsapp-chat-sdk): Build WhatsApp agents with Chat SDK and the Kapso adapter for webhooks, threaded replies, buttons, media, and conversation history.
- [WhatsApp Codex](https://kapso.com/whatsapp-codex): Connect Codex to Kapso WhatsApp MCP or the Kapso CLI for WhatsApp numbers, messages, conversations, templates, webhooks, and customer onboarding.
- [WhatsApp Claude Code](https://kapso.com/whatsapp-claude-code): Connect Claude Code to Kapso WhatsApp MCP for WhatsApp numbers, messages, conversations, templates, webhooks, and customer onboarding.
- [WhatsApp OpenClaw](https://kapso.com/whatsapp-openclaw): Connect OpenClaw agents to WhatsApp with the Kapso OpenClaw plugin, sender numbers, webhooks, allowlists, and diagnostics.
- [WhatsApp Hermes Agent](https://kapso.com/whatsapp-hermes-agent): Connect Hermes Agent to WhatsApp with the Kapso Hermes Agent plugin, webhooks, MessageEvents, sender numbers, media, and STT support.
- [Twilio Alternative for WhatsApp](https://kapso.com/twilio-alternative-for-whatsapp): Evaluate Kapso as a WhatsApp-focused alternative for teams that need lower message costs, customer-owned numbers, automation, agent tools, and human handoff.
- [WhatsApp Human Handoff](https://kapso.com/whatsapp-human-handoff): Route WhatsApp AI agents and workflows to human agents with handoff nodes, inbox ownership, context, and conversation history.
- [Blog](https://kapso.com/blog): Product updates, guides, and engineering notes from Kapso.
- [WhatsApp Groups API waitlist](https://kapso.com/whatsapp-groups): Join the waitlist for Kapso WhatsApp Groups API access.
- [Careers](https://kapso.com/careers): Open roles at Kapso.
- [Privacy](https://kapso.com/privacy): Kapso privacy policy.
- [API de WhatsApp para desarrolladores](https://kapso.com/es/api-whatsapp-para-desarrolladores): Envía y recibe mensajes de WhatsApp con APIs, webhooks, CLI, MCP, plantillas y workflows de Kapso.
- [Agentes de IA para WhatsApp](https://kapso.com/es/agentes-ia-whatsapp): Crea agentes de IA para WhatsApp con la API oficial, Kapso Workflows, webhooks, MCP y handoff humano.
- [Alternativa a Twilio para WhatsApp](https://kapso.com/es/alternativa-twilio-whatsapp): Compara Kapso y Twilio para WhatsApp si necesitas costos más bajos, números de clientes, automatización, agentes y handoff humano.
- [Guides](https://kapso.com/guides): Free written guides on how the WhatsApp Business Platform behaves.
- [WhatsApp Pricing: What Meta charges for](https://kapso.com/guides/whatsapp-pricing/how-pricing-works/what-meta-charges-for): Meta charges per delivered message, priced by the message's category and the recipient's country. The rule that has kept replies free changes on October 1, 2026.
- [WhatsApp Pricing: Message categories](https://kapso.com/guides/whatsapp-pricing/how-pricing-works/message-categories): Meta prices per category: marketing, utility, authentication and service. Meta decides which one a template gets, and can change it after approval.
- [WhatsApp Pricing: The 24-hour window](https://kapso.com/guides/whatsapp-pricing/how-pricing-works/the-24-hour-window): A customer message opens a 24-hour window. Through September 30 it makes service replies and utility templates free; October changes that.
- [WhatsApp Pricing: Pricing by country](https://kapso.com/guides/whatsapp-pricing/how-pricing-works/pricing-by-country): The rate depends on your recipient's country, not yours. When there's no phone number, the country comes from the BSUID prefix instead.
- [WhatsApp Pricing: How a message gets priced](https://kapso.com/guides/whatsapp-pricing/how-pricing-works/how-a-message-gets-priced): You can estimate the price of a message at send time. The price that actually bills arrives after delivery, on the status webhook.
- [WhatsApp Pricing: Pricing inside the service window](https://kapso.com/guides/whatsapp-pricing/october-1-2026/service-message-pricing): From October 1, 2026, service messages and utility templates inside the customer service window are billed at each market's utility rate.
- [WhatsApp Pricing: Estimating your exposure](https://kapso.com/guides/whatsapp-pricing/october-1-2026/estimating-your-exposure): A repeatable method for working out what October 1 does to your own bill, using message history you already have.
- [WhatsApp Pricing: Reducing costs](https://kapso.com/guides/whatsapp-pricing/october-1-2026/reducing-costs): Fewer turns per conversation, fewer messages per turn, and template categories that stay utility.
- [WhatsApp Pricing: Before October 1](https://kapso.com/guides/whatsapp-pricing/october-1-2026/before-october-1): The guide in four sentences, and a four-step checklist to work through before October 1.
- [Business-scoped user IDs: Usernames and BSUIDs](https://kapso.com/guides/business-scoped-user-ids/introduction/usernames-and-bsuids): Meta added BSUIDs to every webhook in April 2026 and is only now removing phone numbers. Usernames and BSUIDs are separate features, and you get a BSUID whether or not the user has a username.
- [Business-scoped user IDs: Reading the new payload](https://kapso.com/guides/business-scoped-user-ids/introduction/reading-the-new-payload): An inbound message can carry a phone number, a BSUID and a username. Which of them actually arrive depends on the user and on how far the rollout has reached them.
- [Business-scoped user IDs: Portfolio scoping](https://kapso.com/guides/business-scoped-user-ids/identity/portfolio-scoping): A BSUID is scoped to a business portfolio, not to a WABA and not to a phone number. The same person can have more than one, and they don't work across portfolios.
- [Business-scoped user IDs: Matching and merging](https://kapso.com/guides/business-scoped-user-ids/identity/matching-and-merging): When the phone number stops arriving, a lookup by phone misses and creates a second record for a customer you already have. There's no way to merge the two afterwards.
- [Business-scoped user IDs: Sending to a BSUID](https://kapso.com/guides/business-scoped-user-ids/messaging/sending-to-a-bsuid): A send can address a phone number, a BSUID, or both. If you send both, Meta uses the phone number, and authentication templates won't accept a BSUID at all.
- [Business-scoped user IDs: Asking for a phone number](https://kapso.com/guides/business-scoped-user-ids/messaging/asking-for-a-phone-number): A button asks the user to share their number, and Meta's contact book stores the ones you've already exchanged messages with. Expect a growing share to decline.
- [Business-scoped user IDs: Migration checklist](https://kapso.com/guides/business-scoped-user-ids/messaging/migration-checklist): Every change the guide covered, grouped by storage, inbound, outbound and downstream, plus what Kapso already handles.
- [llms.txt](https://kapso.com/llms.txt): Curated Kapso context for AI agents and LLM clients.
- [llms-full.txt](https://kapso.com/llms-full.txt): Extended Kapso public context for AI agents and LLM clients.
- [AGENTS.md](https://kapso.com/AGENTS.md): Public instructions for coding agents using Kapso.
- [Authentication](https://kapso.com/auth.md): OAuth discovery, consent, and MCP credentials.
- [sitemap.md](https://kapso.com/sitemap.md): Markdown sitemap for Kapso public pages.