feat: add Twilio plugin

README.md

@@ -31,6 +31,7 @@ Each plugin lives in `plugins/<slug>`. The directory name is the install keyword
 | `mac-notify` | macOS notifications when a Cline run completes. |
 | `nanobanana` | Image generation through OpenRouter and Gemini image models. |
 | `speak` | Speaks completed Cline replies with ElevenLabs text to speech. |
+| `twilio` | Twilio and SendGrid workflow skills plus the Twilio docs MCP. |
 | `typescript-lsp` | TypeScript language service `goto_definition` support. |
 | `weather-metrics` | Demo weather tool plus runtime metrics hooks. |
 | `web-search` | Exa-backed web search as a Cline tool. |

plugins/twilio/LICENSE.twilio-developer-kit

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Twilio
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

plugins/twilio/README.md

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+# Twilio
+
+Twilio bundles workflow skills for building with Twilio and SendGrid, plus the public Twilio docs MCP server for documentation and API-schema lookup.
+
+## What It Adds
+
+- 55 Twilio and SendGrid skills covering SMS, WhatsApp, RCS, Voice, Verify, Lookup, Messaging Services, regulatory onboarding, webhooks, Conversation Orchestrator, Conversation Intelligence, Customer Memory, SendGrid sending, deliverability, inbound parse, suppressions, and event webhooks.
+- `twilio-docs`, a streamable HTTP MCP server at `https://mcp.twilio.com/docs` for semantic Twilio documentation search and API operation retrieval. The docs MCP does not require authentication.
+- Bundled guidance for live messaging, email, voice, verification, compliance, and customer-data workflows.
+
+## Requirements
+
+- Cline with plugin MCP support.
+- A Twilio account and credentials such as `TWILIO_ACCOUNT_SID` and `TWILIO_AUTH_TOKEN` for live Twilio API work.
+- A SendGrid account and `SENDGRID_API_KEY` for SendGrid email workflows.
+- Valid sender identities, phone numbers, WhatsApp senders, regulatory registrations, webhook URLs, and user consent for the channels you plan to use.
+
+## Trust Boundaries
+
+Installing this plugin registers only the unauthenticated Twilio documentation MCP and bundled local skills. It does not send messages, place calls, create resources, read account data, or contact Twilio or SendGrid APIs with user credentials during setup.
+
+Review live sends, calls, OTPs, compliance changes, number purchases or releases, credential changes, webhook exposure, and production-traffic changes before allowing Cline to execute them.
+
+## Install
+
+```bash
+cline plugin install twilio
+```
+
+For local development:
+
+```bash
+cline plugin install ./plugins/twilio --cwd .
+```

plugins/twilio/index.ts

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+import type { AgentPlugin } from "@cline/sdk"
+
+const plugin: AgentPlugin = {
+	name: "twilio",
+	manifest: {
+		capabilities: ["mcp", "skills"],
+	},
+	setup(api) {
+		api.registerMcpServer({
+			name: "twilio-docs",
+			transport: {
+				type: "streamableHttp",
+				url: "https://mcp.twilio.com/docs",
+			},
+		})
+	},
+}
+
+export default plugin

plugins/twilio/package.json

@@ -0,0 +1,20 @@
+{
+  "name": "twilio",
+  "version": "0.0.0",
+  "private": true,
+  "type": "module",
+  "description": "Cline plugin that bundles Twilio and SendGrid workflow skills with the Twilio docs MCP.",
+  "cline": {
+    "plugins": [
+      {
+        "paths": [
+          "./index.ts"
+        ],
+        "capabilities": [
+          "mcp",
+          "skills"
+        ]
+      }
+    ]
+  }
+}

plugins/twilio/skills/twilio-account-setup/SKILL.md

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+---
+name: twilio-account-setup
+description: >
+  Create and configure a Twilio account from scratch. Covers free trial signup,
+  trial limitations, getting credentials (Account SID and Auth Token), buying
+  a phone number, verifying recipient numbers for trial use, SDK installation,
+  first API call, subaccount management (creation, inheritance, credential
+  isolation, limits), and enabling specific products (AI Assistants,
+  Conversations, Verify, ConversationRelay, WhatsApp). Use this skill before
+  any other Twilio skill if you do not yet have a Twilio account or need to
+  enable a product. For Organization-level governance (SSO, SCIM, multi-team),
+  see `twilio-organizations-setup`.
+---
+
+## Overview
+
+Every Twilio skill requires an active Twilio account and credentials. This skill covers the one-time setup steps that are prerequisites for all other Twilio skills.
+
+---
+
+## Quickstart
+
+1. Sign up at [twilio.com/try-twilio](https://www.twilio.com/try-twilio) -- enter name, email, password
+2. Verify your email and personal phone number
+3. Get your credentials from [Console > Account > API keys & tokens](https://console.twilio.com/us1/account/keys-credentials/api-keys):
+
+```bash
+export TWILIO_ACCOUNT_SID=ACxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+export TWILIO_AUTH_TOKEN=your_auth_token
+```
+
+4. Buy a phone number at [Console > Phone Numbers > Buy a number](https://console.twilio.com/us1/develop/phone-numbers/search). Confirm the account, region, sender type, and expected cost before buying a number.
+
+5. Install the SDK and send your first message. Confirm the destination, sender, body, environment, and user consent before running a live send:
+
+Python
+```bash
+pip install twilio
+```
+```python
+import os
+from twilio.rest import Client
+
+client = Client(os.environ["TWILIO_ACCOUNT_SID"], os.environ["TWILIO_AUTH_TOKEN"])
+message = client.messages.create(
+    to="+15558675310",  # must be verified on trial accounts
+    from_="+15017122661",  # your Twilio number
+    body="Hello from Twilio!"
+)
+print(f"Sent: {message.sid}")
+```
+
+Node.js
+```bash
+npm install twilio
+```
+```node
+const twilio = require("twilio");
+const client = twilio(process.env.TWILIO_ACCOUNT_SID, process.env.TWILIO_AUTH_TOKEN);
+
+const message = await client.messages.create({
+    to: "+15558675310",  // must be verified on trial accounts
+    from: "+15017122661",  // your Twilio number
+    body: "Hello from Twilio!",
+});
+console.log(`Sent: ${message.sid}`);
+```
+
+You're ready to use any Twilio skill. Trial accounts have restrictions -- see Constraints below.
+
+---
+
+## Key Patterns
+
+### Verify Recipient Numbers (trial accounts only)
+
+Trial accounts can only send to verified phone numbers (up to 5 per account).
+
+1. Go to [Console > Phone Numbers > Verified Caller IDs](https://console.twilio.com/us1/develop/phone-numbers/verified-caller-ids)
+2. Click Add a new Caller ID and verify via SMS code
+
+Verified numbers work across both messaging and voice. Remove this restriction by upgrading your account.
+
+### Enable Specific Products
+
+Some products require explicit activation:
+
+| Product | How to enable |
+|---------|--------------|
+| AI Assistants | [Console > Explore Products > AI Assistants](https://console.twilio.com/us1/develop/ai-assistants) > Get started |
+| Conversations | [Console > Conversations > Manage > Overview](https://console.twilio.com/us1/develop/conversations/manage/overview) > Enable Conversations |
+| Verify | [Console > Verify > Services](https://console.twilio.com/us1/verify/services) > Create new |
+| WhatsApp (sandbox) | [Console > Messaging > Try it out > Send a WhatsApp message](https://console.twilio.com/us1/develop/sms/try-it-out/whatsapp-learn) |
+| ConversationRelay | [Console > Voice > ConversationRelay](https://console.twilio.com/us1/voice/conversation-relay) > complete onboarding form |
+
+### SDK Installation
+
+| Language | Install | SDK package |
+|----------|---------|-------------|
+| Python | `pip install twilio` | `twilio` |
+| Node.js | `npm install twilio` | `twilio` |
+| Java | Maven/Gradle | `com.twilio.sdk:twilio` |
+| C# | `dotnet add package Twilio` | `Twilio` |
+| Ruby | `gem install twilio-ruby` | `twilio-ruby` |
+| PHP | `composer require twilio/sdk` | `twilio/sdk` |
+| Go | `go get github.com/twilio/twilio-go` | `twilio-go` |
+
+### Initialize the Client
+
+Always load credentials from environment variables -- never hardcode them.
+
+Python
+```python
+import os
+from twilio.rest import Client
+
+client = Client(os.environ["TWILIO_ACCOUNT_SID"], os.environ["TWILIO_AUTH_TOKEN"])
+```
+
+Node.js
+```node
+const twilio = require("twilio");
+const client = twilio(process.env.TWILIO_ACCOUNT_SID, process.env.TWILIO_AUTH_TOKEN);
+```
+
+For production, use API Keys instead of Auth Token. See `twilio-iam-auth-setup`.
+
+### Twilio CLI Setup
+
+The CLI is useful for quick operations and local webhook testing.
+
+```bash
+# Install (macOS)
+brew tap twilio/brew && brew install twilio
+
+# Install (npm -- all platforms)
+npm install -g twilio-cli
+
+# Login (creates an API key automatically)
+# Confirm this account-level credential change before running.
+twilio login
+
+# Verify setup
+twilio phone-numbers:list
+```
+
+The CLI stores profiles for switching between accounts:
+```bash
+# List profiles
+twilio profiles:list
+
+# Switch active profile
+twilio profiles:use my-project
+
+# Use environment variables instead of profiles
+export TWILIO_ACCOUNT_SID=ACxxxxxxxx
+export TWILIO_AUTH_TOKEN=xxxxxxxx
+```
+
+Precedence: `--profile` flag > environment variables > active profile.
+
+### Accounts and Subaccounts
+
+Creating a new Twilio account: Accounts can only be created from the Console UI - there is no API for creating top-level accounts. A new account is automatically created when a user signs up. Additional accounts can be created from Console > My Accounts (or "View all accounts").
+
+To see all your accounts: Console > My Accounts shows all accounts and subaccounts you have access to. For Organization-wide visibility, see Console > Admin > Accounts (requires Organization admin role). See `twilio-organizations-setup` for Organization-level governance.
+
+### Subaccounts
+
+Subaccounts are child accounts under your main (parent) account. Use them for multi-tenant apps, per-customer isolation, or team separation.
+
+How they differ from the parent account:
+- Resources (numbers, calls, messages) are isolated - a subaccount cannot see the parent's resources or other subaccounts' resources
+- Billing is consolidated to the parent - a single Twilio balance for all subaccounts
+- Voice and SMS permissions inherit from the parent
+- Phone numbers can be transferred between parent and subaccounts
+
+Create via Console: Console > My Accounts > Create Subaccount
+
+Create via API:
+
+Python
+```python
+subaccount = client.api.accounts.create(friendly_name="Customer A")
+print(f"Subaccount SID: {subaccount.sid}")
+# Store securely - auth_token is only shown at creation time
+# e.g., secrets_manager.store("subaccount_auth_token", subaccount.auth_token)
+```
+
+Node.js
+```javascript
+const subaccount = await client.api.accounts.create({ friendlyName: "Customer A" });
+console.log(`Subaccount SID: ${subaccount.sid}`);
+```
+
+### Subaccount Credential Isolation
+
+Always use the subaccount's own credentials (API Keys or Auth Token) when accessing subaccount resources - do NOT use the parent account's credentials as a shortcut.
+
+Python - access subaccount resources
+```python
+# Correct: use subaccount credentials
+sub_client = Client(subaccount.sid, subaccount.auth_token)
+call = sub_client.calls.create(
+    to="+15558675310",
+    from_="+15017122661",  # number owned by this subaccount
+    url="https://yourapp.com/voice"
+)
+
+# Also correct: parent credentials with subaccount SID (v2010 API only)
+parent_client = Client(os.environ["TWILIO_ACCOUNT_SID"], os.environ["TWILIO_AUTH_TOKEN"])
+calls = parent_client.api.accounts(subaccount.sid).calls.list()
+```
+
+Critical: Resources on separate subdomains (`studio.twilio.com`, `taskrouter.twilio.com`) require subaccount-specific credentials. Parent account credentials will not work on these subdomains.
+
+### Subaccount Limits
+
+- Default limit: 1,000 subaccounts per parent account
+- Trial accounts: Can create only 1 subaccount - upgrade to create more
+- At the limit: Contact Twilio Support with your use case to request an increase
+- Closing: Set status to `closed` via API or Console. Closed subaccounts are automatically deleted after 30 days
+- Suspension cascade: Suspending the parent account automatically suspends ALL subaccounts
+
+### Upgrade from Trial
+
+1. Click Upgrade at the top of the Console, or go to [Console > Admin > Account billing](https://console.twilio.com/us1/admin/billing)
+2. Provide name, address, and payment details
+3. Your trial phone number carries over; trial balance does not
+
+---
+
+## Trial Restrictions at a Glance
+
+| Feature | Trial | Upgraded |
+|---------|-------|----------|
+| Phone numbers | 1 | Unlimited |
+| Send to unverified numbers | No | Yes |
+| Outbound message prefix | Yes (visible to recipient) | No |
+| Verified caller IDs | Up to 5 | Not needed |
+| A2P 10DLC registration | No | Yes |
+| Daily WhatsApp messages | 50 | Unlimited |
+| ConversationRelay | No | Yes (after onboarding) |
+| Voice: outbound calls | Domestic only | International |
+
+---
+
+## CANNOT
+
+- Cannot create top-level accounts via API - Only Console UI. A new account is created at signup; additional accounts from Console > My Accounts.
+- Cannot create more than 1 subaccount on trial - Upgrade your account first, then you can create up to 1,000.
+- Cannot access subdomain resources with parent credentials - Studio, TaskRouter, and other subdomain APIs require subaccount-specific credentials. Parent credentials return auth errors.
+- Cannot undo a closed subaccount after 30 days - Closed subaccounts are permanently deleted. Suspension is reversible; closure is not.
+- Cannot transfer trial balance to a paid account - Trial credits are forfeited on upgrade.
+- Cannot send to unverified numbers on trial - Only verified Caller IDs (up to 5) can receive messages or calls.
+- Auth Token rotation invalidates ALL API keys - This is a one-way door. Use API Keys from day one. See `twilio-security-api-auth`.
+- API Key secrets shown only once at creation - Store them immediately. Cannot be retrieved afterward.
+- AI Assistants and ConversationRelay require approval - Limited access products. Activation is not instant.
+
+---
+
+## Next Steps
+
+- Organization governance (SSO, SCIM, multi-team): `twilio-organizations-setup`
+- Secure credential management and API Keys: `twilio-security-api-auth`
+- Send your first SMS: `twilio-sms-send-message`
+- Send your first WhatsApp message: `twilio-whatsapp-send-message`
+- Receive incoming messages: `twilio-messaging-webhooks`
+- US SMS compliance (A2P 10DLC): `twilio-compliance-onboarding`
+- Webhook setup: `twilio-webhook-architecture`