# Sinch Skills

Sinch Skills are structured knowledge files that give AI coding agents expert-level context for every Sinch API. Install once and your agent can authenticate, build, and execute Sinch integrations without searching documentation or guessing at patterns.

**17 skills ship at launch**, covering SMS, voice, WhatsApp, verification, email, numbers, video, SIP trunking, and fax.

## What are Sinch Skills?

Sinch Skills are files your AI coding agent reads as context. Each skill is a directory containing a `SKILL.md` file with structured instructions, best practices, gotchas, and working code examples for a specific Sinch API.

Skills follow the [Agent Skills](https://skills.sh/) open standard and work with any AI coding tool that supports `SKILL.md` files, including Claude Code, Gemini CLI, Cursor, Codex, GitHub Copilot, and Windsurf.

### How skills work

Skills use progressive disclosure to avoid overloading your agent's context window:

1. **Discovery** — When your agent starts, it loads only the name and description of each installed skill. It knows what skills exist and when to use them.
2. **Execution** — When a task matches a skill, the agent reads the full `SKILL.md` and any referenced scripts or assets.
3. **Action** — The agent generates code guided by expert Sinch knowledge, not generic training data.


This means your agent gets deep API knowledge exactly when it needs it — not all at once.

### What a skill contains

Every Sinch skill follows the same structure:

| Section | What it covers |
|  --- | --- |
| Overview | What the API does, when to use it, and what it does not cover |
| Getting started | The first API call with working code and auth included |
| Key concepts | Terms, enums, data models, and decision trees |
| Common patterns | Real workflows including async state management and edge cases |
| Gotchas and best practices | Regional endpoints, auth constraints, retry safety, field defaults |
| Links | API reference, OpenAPI spec, SDK docs, and community resources |


## Prerequisites

In order to use Sinch Skills, you must have:

- Node.js and npm installed
- A valid [Sinch account](https://dashboard.sinch.com/)
- An AI coding tool that supports `SKILL.md` files (for example, Claude Code, Gemini CLI, Cursor, Codex, GitHub Copilot, Windsurf, and others)


Skills are free to install and open source under Apache-2.0. Using the Sinch APIs the skills describe requires a Sinch account with access to the relevant products.

## Quickstart

You can either use npm or the Sinch Plugins repository to install Sinch Skills quickly. Click the corresponding tab for more information:

Install using npm
### Install all skills

Run the following command in your terminal to install the full Sinch skills library:

`npx skills add sinch/skills`

This adds all 17 skills to your AI coding agent environment immediately. No separate dashboard, no configuration, no context switching.

### Verify installation

List your installed skills to confirm:

`npx skills list`

You should see the Sinch skills listed by name.

Install using Sinch Plugins
### Install Sinch Skills via Sinch Plugins

If you prefer to install through the Sinch Plugins repository, or want to install individual skills, visit the [Sinch Plugins repository](https://github.com/sinch/sinch-plugins) for setup instructions.

Individual skill installation is supported. See the [Sinch Plugins repository](https://github.com/sinch/sinch-plugins) for per-skill install instructions.

## Start building

Once your Sinch Skills have been installed, you can begin building your code. Open your AI coding agent and reference any Sinch API. Your agent already has the context it needs.

For example, you can try the following prompt:

`Send an SMS to +1202555XXXX.`

Your agent will read the relevant skill, select the correct auth method, apply the right regional endpoint, and generate accurate code — without you needing to provide API documentation.

## Skills reference

The following sections identify which Sinch Skill folder correspond to Sinch's product offerings.

### Core

| Skill | What it covers |
|  --- | --- |
| `sinch-authentication` | OAuth2, API keys, SDK initialization, and dashboard links for every Sinch API |


### Messaging

| Skill | What it covers |
|  --- | --- |
| `sinch-conversation-api` | Omnichannel messaging across WhatsApp, SMS, RCS, MMS, Viber, and 11 channels; inbound handling; webhook setup; processing modes |
| `sinch-provisioning-api` | Channel provisioning and configuration for Conversation API |


### Voice and video

| Skill | What it covers |
|  --- | --- |
| `sinch-voice-api` | Callouts, IVR trees, TTS, conferencing, call recording, SVAML call control |
| `sinch-in-app-calling` | In-app voice and video SDK, client SDK integration |
| `sinch-elastic-sip-trunking` | SIP trunk provisioning, PSTN routing, regional endpoint rules |


### Email

| Skill | What it covers |
|  --- | --- |
| `sinch-mailgun` | Transactional email, sending, webhooks, and domain verification |
| `sinch-mailgun-inspect` | Email preview and rendering across clients |
| `sinch-mailgun-optimize` | Deliverability optimization |
| `sinch-mailgun-validate` | Email address validation |


### Numbers

| Skill | What it covers |
|  --- | --- |
| `sinch-numbers-api` | Number search, provisioning, and inventory management |
| `sinch-number-order-api` | Number ordering workflows and async approval |
| `sinch-imported-numbers-hosting-orders` | Number hosting, KYC compliance, and import flows |
| `sinch-10dlc` | US A2P SMS compliance: brand registration, campaign qualification, TCR rejection patterns, and the full six-step workflow |


### Verification

| Skill | What it covers |
|  --- | --- |
| `sinch-verification-api` | SMS, voice, flashcall, and WhatsApp verification flows; Application Key auth pattern |
| `sinch-number-lookup-api` | Number lookup and validation |


### Other

| Skill | What it covers |
|  --- | --- |
| `sinch-fax-api` | Send and receive faxes programmatically |


## Common questions

Below are answers to common questions regarding Agent Skills.

### What is the difference between Sinch Skills and the Sinch API documentation?

API documentation is comprehensive and complete — it covers every parameter, every response, every edge case. A skill is opinionated and concise. It tells your AI agent what to do, in what order, and what to watch out for. Skills reference the full API docs when you need to go deeper.

### What is the difference between Sinch Skills and an MCP server?

MCP (Model Context Protocol) servers expose tools that let an agent take actions — calling an API, reading a database, sending a message. Skills provide knowledge — instructions, patterns, and context that guide how the agent writes code. They are complementary. Skills improve the code your agent generates. MCP servers enable the agent to act autonomously at runtime.

### Which AI coding tools are supported?

Skills work with any tool that supports `SKILL.md` files: Claude Code, Gemini CLI, Cursor, Codex, GitHub Copilot, OpenCode, Windsurf, and others. Check [skills.sh](https://skills.sh/?q=Sinch) for the current list of supported environments.

### What languages and SDKs do skills support?

Code examples use `curl` and the Node.js SDK (`@sinch/sdk-core`). Mailgun skills use `mailgun.js`.

SDK information for Node.js, Python, Java, and .NET are included in skill directories for products that have SDK support.

### Can I install individual skills instead of the full library?

Yes. Specify the skill name during install. You can do so using npm: `npx skills add sinch/skills --skill SKILL_NAME` (for example, `npx skills add sinch/skills --skill sinch-conversation-api`).

You can also install individual skills via plugin; see the [Sinch Plugins repository](https://github.com/sinch/sinch-plugins) for individual install instructions.

### Are skills kept up to date?

Each skill includes a version field in its frontmatter. The repository is updated as APIs change. Check [github.com/sinch/skills](https://github.com/sinch/skills) for the current version of each skill.

To keep updated automatically, use the [Sinch Plugin(s)](https://github.com/sinch/sinch-plugins).

### Can I contribute a skill or suggest improvements?

Yes. The repository is open source under Apache-2.0. Create a `SKILL.md` file following the contribution guidelines in the readme and submit a pull request at [github.com/sinch/skills](https://github.com/sinch/skills).

## Supported agents

Any agent supported by [skills.sh](https://skills.sh/?q=Sinch) is supported by Sinch Skills, including these notable examples:

- Claude Code
- Gemini CLI
- Cursor
- OpenAI Codex
- GitHub Copilot
- OpenCode
- Windsurf


## Resources

For more information, visit any of the following links:

- [Skills repository](https://github.com/sinch/skills) — source of truth for all Sinch skills
- [Sinch Plugins repository](https://github.com/sinch/sinch-plugins) — plugin setup for Claude Code, Gemini CLI, and others
- [Agent Skills directory](https://skills.sh/?q=Sinch) — discover and browse Sinch skills
- [Sinch Dashboard](https://dashboard.sinch.com/) — manage your Sinch account and API keys
- [Sinch developer documentation](https://developers.sinch.com/) — full documentation for every Sinch API