Kaption WhatsApp (Cloud)

Name: Kaption WhatsApp (Cloud)
Author: Kaption-AI

by Kaption-AIversion 1.0.0i★ –iRuns in the cloud

Registry nameio.github.Kaption-AI/mcp-extension-remote

Install

Overview

Description from the maker (original English)

Use WhatsApp from AI apps through the Kaption extension. OAuth 2.1 relay that cannot read messages.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Runs in the cloud
Transport: Streamable HTTP
Category: Chat & email

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on the maker’s server: what you ask it goes through their server.
The registry lists no key to fill in.

You need

Runs in the cloudNothing to install; it connects over the internet

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Works in Claude on the web, desktop and mobile:

Open Settings → Connectors
Press Add custom connector
Paste the address below and press Add
If it asks you to sign in, sign in with the maker

https://mcp.kaptionai.com/mcp

Run this in your terminal

claude mcp add --transport http extension-remote https://mcp.kaptionai.com/mcp

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "extension-remote": {
      "url": "https://mcp.kaptionai.com/mcp"
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "extension-remote": {
      "type": "http",
      "url": "https://mcp.kaptionai.com/mcp"
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

ChatGPT connects only to servers on the internet:

Open ChatGPT on the web → Settings → Connectors (Apps)
Press Create or Add (some plans need Developer mode under Advanced first)
Paste the address below, give it a name and save
If it asks you to sign in, sign in with the maker

https://mcp.kaptionai.com/mcp

Menu names can differ slightly by plan and over time.

Your choice stays on this device in a cookie; no account needed.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

We have not read this server’s tool list yet; we check endpoints in rotation.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 7, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account Kaption-AI, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
… Not checked yet
Endpoint responds
Not checked yet; we check endpoints in rotation
… Not checked yet
Sign-in with OAuth
Not checked yet; we check endpoints in rotation
… Not checked yet
No hidden instructions in tool descriptions
Not checked yet; we read the tool list when we check the endpoint

Compared with others in Chat & emaili

More stars than 0% of the other 1832 servers in this category
Published to the registry more recently than 45% of the other 1832 servers in this category
Basic checks equal to or better than 100% of the other 1832 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is Kaption WhatsApp (Cloud) safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

It runs in the maker’s cloud. Connect over the internet with nothing to install, but what you send passes through the maker’s servers.

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.0.0) reached the registry 34 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT in developer mode.

What can I use instead?

In the same category: Vexa, emailmd, MCP WhatsApp Cloud

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Vexa

by Vexa-ai

Meeting bot and transcripts for Google Meet, Teams and Zoom. Live or after, speakers labelled.

Runs in the cloud★ 2,949Apache-2.0Updated 2 months ago

Install

emailmd

by anypost

Render markdown into email-safe HTML, lint drafts for deliverability problems, and preview emails.

Computer or cloud★ 1,385MITUpdated 32 days ago

Install

MCP WhatsApp Cloud

by codespar

MCP server for WhatsApp Cloud API (Meta) — messages, media, and templates via Graph API

Runs on your computer★ 277MITUpdated 5 months ago

Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

kaption-mcp-remote

Cloud MCP relay for WhatsApp — lets AI assistants (Claude, ChatGPT, Cursor, etc.) interact with your WhatsApp conversations through the Model Context Protocol.

Setup guide: kaptionai.com/mcp — connect WhatsApp to Claude, ChatGPT or Cursor.

Live at: mcp.kaptionai.com (canonical) and mcp-ext.kaptionai.com (backward-compatible alias for existing connections)

The relay cannot read your messages. It forwards MCP tool calls between the AI client and the Kaption browser extension, which processes everything locally in your browser. Its source code is public (BUSL-1.1), so you can verify it yourself.

Architecture

AI Client (Claude/ChatGPT/Cursor)

│ │ OAuth 2.1 + SSE/Streamable HTTP ▼ ┌─────────────────────────────────────┐ │ Cloudflare Worker │ │ mcp.kaptionai.com │ │ │ │ ┌────────────┐ ┌──────────────┐ │ │ │ OAuthProv │ │ Next.js │ │ │ │ /sse /mcp │ │ /authorize │ │ │ │ /token │ │ /ext-auth │ │ │ │ /register │ │ / (landing) │ │ │ └─────┬──────┘ └──────────────┘ │ │ │ │ │ ┌─────▼──────┐ ┌──────────────┐ │ │ │ RelayMCP │ │ Deployment │ │ │ │ (DO) │ │ ChainDO │ │ │ └─────┬──────┘ └──────────────┘ │ │ │ │ │ ┌─────▼──────┐ │ │ │ RelayRoom │ ◄── WebSocket ──┐ │ │ │ (DO/accountRef) │ │ │ │ └────────────┘ │ │ └─────────────────────────────────┼──┘ │ Browser Extension (WhatsApp Web tab)

Durable Objects

DO	Keyed By	Purpose
RelayMCP	OAuth session	McpAgent — registers tools, relays JSON-RPC to RelayRoom
RelayRoom	Opaque accountRef	WebSocket bridge to extension, auth handshake, request/response matching
DeploymentChainDO	`"main"`	Append-only hash chain for deployment transparency

Request Flow

AI client discovers the MCP server via /.well-known/oauth-authorization-server
Client registers dynamically via POST /register (RFC 7591)
User authenticates with WhatsApp OTP at /authorize
Client exchanges code for token at /token
Client sends tool calls via SSE (/sse) or Streamable HTTP (/mcp)
RelayMCP DO receives the call, routes to RelayRoom for the accountRef
RelayRoom forwards JSON-RPC to the extension over WebSocket
Extension executes in WhatsApp Web context, returns result
Result flows back: RelayRoom → RelayMCP → AI client

Routing Table

Path	Method	Auth	Handler
`/`	GET	—	Next.js landing page
`/authorize`	GET	—	Next.js OTP form (HMAC-signed oauthReqInfo)
`/authorize/send-otp`	POST	—	Next.js API route → rest-api
`/authorize/verify`	GET/POST	—	Next.js OTP verify → OAuthProvider completeAuthorization
`/authorize/reviewer-login`	POST	Static review credentials	Password completion for the configured synthetic review phone
`/register`	POST	—	OAuthProvider (RFC 7591 dynamic client registration)
`/token`	POST	—	OAuthProvider (token exchange)
`/sse`	GET	OAuth token	RelayMCP DO (SSE transport)
`/mcp`	POST	OAuth token	RelayMCP DO (Streamable HTTP)
`/ws/ext`	GET	JWT/token in auth msg	RelayRoom DO (WebSocket upgrade)
`/ext-auth/*`	Various	—	Next.js extension auth pages + API
`/transparency`	GET	—	DeploymentChainDO (chain history)
`/transparency/latest`	GET	—	DeploymentChainDO (latest entry)
`/transparency/verify`	GET	—	DeploymentChainDO (chain integrity)
`/transparency/gaps`	GET	CF token	Cross-reference CF deploys with chain
`/transparency/append`	POST	DEPLOY_API_KEY	Append entry (CI only)

MCP Tools

26 public tools are forwarded to the extension (the relay does not execute them). Reads and writes are separate tools: every read-only tool carries readOnlyHint: true, and the manage_* tools only write. The read tools for reminders, scheduled messages, chat lists and contact notes reach the extension as the matching manage_* call (TOOL_ROUTES in src/tools.ts), so every Kaption version answers them.

Tool	Kind	Description
`query`	read	Query conversations, contacts, messages, transcriptions, labels, communities, sessions
`summarize_conversation`	write (private cache)	Get or generate a conversation summary
`download_media`	read	Download image/video/audio/document from a message
`list_contacts`, `get_contact`, `get_contact_groups`	read	Read contacts and their group memberships
`list_groups`, `get_group`	read	Read cached or live group metadata
`export_contacts`	read	Export contacts as CSV or JSON
`get_analytics`	read	Analyze WhatsApp activity, rankings, response times, and exports
`call_recordings`	read	List, read and search call recordings and transcripts
`list_reminders`, `get_reminder`	read	Read personal reminders
`list_scheduled_messages`, `get_scheduled_message`	read	Read scheduled messages (both modes)
`list_chat_lists`, `get_chat_list`	read	Read personal chat lists
`get_contact_note`	read	Read a contact's note (Business accounts)
`manage_labels`	write	Add/remove/create/delete WhatsApp Business labels
`manage_notes`	write	Set a contact's note (Business accounts)
`manage_chat`	write	Archive, pin, mute, mark read/unread, set/clear draft
`manage_reminders`	write	Create/update/complete/delete personal reminders
`manage_scheduled_messages`	write	Schedule, change or cancel messages — from Kaption's number (bot, default) or from your own number on this computer (`mode: "local"`, also to groups)
`manage_lists`	write	Create/edit/delete personal chat lists and their chats
`send_message`	write	Queue a message from your own number (needs sending from this computer turned on and consent in Kaption)
`create_attachment_upload`	write	One-time upload slot for an attachment to send or schedule

The square brand icon for directory listings and consent screens is served at /brand/kaption-mcp-icon.svg.

get_api_info is local-only and is deliberately excluded from the cloud surface because it returns private REST connection credentials.

Deployment Security

Every deployment is cryptographically signed and recorded in a tamper-evident transparency chain. See SECURITY.md for full details.

Pipeline

GitHub Actions (push to main)

│ ├─ 1. Run tests ├─ 2. Build worker (OpenNext + wrap) ├─ 3. SHA-256 manifest every generated code and asset file ├─ 4. Pre-deploy: Sigstore sign the manifest → Rekor log ├─ 5. Deploy to Cloudflare ├─ 6. Post-deploy: verify hash unchanged, sign attestation → Rekor └─ 7. Append to transparency chain (hash-linked)

Daily heartbeat redeploys (6am UTC) ensure the chain stays active even without code changes.

Deploys are gated — do NOT run `wrangler deploy` locally

All production deploys go through GitHub Actions. Multiple layers enforce this:

wrangler.jsonc is gitignored; scripts/build-config.mjs renders it from wrangler.template.jsonc and refuses to run unless GITHUB_ACTIONS=true + GITHUB_RUN_ID are set (or KAPTIONAI_LOCAL_DEV=1 for dev).
npm run predeploy aborts unless those same CI env vars are present.
main is branch-protected: requires a reviewed PR + green test, deploy, and verify checks.
CODEOWNERS routes every PR through @kshmir.

To ship a change: open a PR → review + CI green → merge to main → Actions builds, signs (Sigstore), deploys, and appends to the transparency chain. npx wrangler deploy from a laptop will fail at step 1 because there is no wrangler.jsonc to deploy.

Verify a Deployment

# 1. Check the transparency chain

curl -s https://mcp.kaptionai.com/transparency/latest | jq .

2. Verify chain integrity

curl -s https://mcp.kaptionai.com/transparency/verify | jq .

3. Verify Sigstore signature (requires cosign)

COMMIT=$(curl -s https://mcp.kaptionai.com/transparency/latest | jq -r '.event.commitSha') cosign verify-blob \ --bundle build-manifest.sigstore.json \ --certificate-identity-regexp "https://github.com/Kaption-AI/mcp-extension-remote/.*" \ --certificate-oidc-issuer "https://token.actions.githubusercontent.com" \ build-manifest.json

API Endpoints

Transparency API (public, no auth)

# Full chain history (paginated)

GET /transparency?limit=50&offset=0

Latest deployment

GET /transparency/latest

Verify chain integrity

GET /transparency/verify

MCP (OAuth-protected)

# SSE transport (for Claude Code, Cursor)

GET /sse

Streamable HTTP transport

POST /mcp

Development

# Install dependencies

npm install

Run tests

npm test

Dev server (Next.js only — no Worker routing)

npm run dev

Build the full worker (OpenNext + custom wrapper)

npm run build:worker

Project Structure

src/

index.ts # Worker entry — Hono routing, OAuthProvider composition relay-mcp.ts # RelayMCP Durable Object (McpAgent) relay-room.ts # RelayRoom Durable Object (WebSocket bridge) deployment-chain.ts # DeploymentChainDO (transparency log) otp.ts # OTP generation, verification, JWT, HMAC, rate limiting schemas.ts # Zod schemas for API request validation tools.ts # MCP tool definitions (forwarded, not executed) types.ts # TypeScript interfaces (Env, DeploymentEvent, etc.) app/ page.tsx # Landing page (multilingual, client-side i18n) layout.tsx # Root layout i18n.ts # i18next init (8 languages) locales/ # Translation JSON files authorize/ # OAuth OTP flow pages + API routes ext-auth/ # Extension auth pages + API routes scripts/ wrap-worker.mjs # Post-build: wraps OpenNext output with custom routing

Environment Variables

Vars (wrangler.jsonc)

Variable	Description
`INTERNAL_API_BASE_URL`	Backend API base URL
`BUILD_HASH`	SHA-256 of worker bundle (set by CI)
`COMMIT_SHA`	Git commit SHA (set by CI)

Secrets (`wrangler secret put`)

Secret	Description
`INTERNAL_API_KEY`	API key for rest-api OTP endpoint
`DEPLOY_API_KEY`	API key for transparency chain append
`JWT_SECRET`	Shared JWT signing secret (same as rest-api, schedule, metadata workers)
`PHONE_REF_SECRET`	HMAC secret used to derive opaque durable account references from phone numbers
`EPHEMERAL_STATE_SECRET`	Encryption secret for short-lived login hints, verify tickets, and encrypted session phone payloads
`OPENAI_APPS_CHALLENGE_TOKEN`	Exact domain-verification token issued by the OpenAI plugin portal
`OPENAI_REVIEW_PASSWORD_SHA256`	Lowercase SHA-256 hex digest of the high-entropy reviewer password
`OPENAI_REVIEW_PHONE`	Phone number used as the dedicated review username and to derive the synthetic account's opaque reference

The three OPENAI_* values are also configured as GitHub Actions repository secrets. Add all three together, then run the manual Test, Build & Deploy workflow. CI writes them to an ephemeral mode-0600 file and passes that file to wrangler deploy --secrets-file, so the review configuration ships in the same signed, attested Worker version as the code. The workflow fails closed if only part of the three-value set is present and deletes the temporary file immediately after deployment. Existing Worker

Only the beginning is shown; read the rest in the repo

Kaption WhatsApp (Cloud)

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Chat & emaili

Common questions

Alternatives

Vexa

emailmd

MCP WhatsApp Cloud

README from the maker

kaption-mcp-remote

Architecture

Durable Objects

Request Flow

Routing Table

MCP Tools

Deployment Security

Pipeline

Deploys are gated — do NOT run wrangler deploy locally

Verify a Deployment

2. Verify chain integrity

3. Verify Sigstore signature (requires cosign)

API Endpoints

Transparency API (public, no auth)

Latest deployment

Verify chain integrity

MCP (OAuth-protected)

Streamable HTTP transport

Development

Run tests

Dev server (Next.js only — no Worker routing)

Build the full worker (OpenNext + custom wrapper)

Project Structure

Environment Variables

Vars (wrangler.jsonc)

Secrets (wrangler secret put)

Deploys are gated — do NOT run `wrangler deploy` locally

Secrets (`wrangler secret put`)