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.
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 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.
Skills use progressive disclosure to avoid overloading your agent's context window:
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.
Execution — When a task matches a skill, the agent reads the full
SKILL.mdand any referenced scripts or assets.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.
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 |
In order to use Sinch Skills, you must have:
Node.js and npm installed
A valid Sinch account
An AI coding tool that supports
SKILL.mdfiles (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.
You can either use npm or the Sinch Plugins repository to install Sinch Skills quickly. Click the corresponding tab for more information:
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.
List your installed skills to confirm:
npx skills list
You should see the Sinch skills listed by name.
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.
The following sections identify which Sinch Skill folder correspond to Sinch's product offerings.
| Skill | What it covers |
|---|---|
sinch-authentication | OAuth2, API keys, SDK initialization, and dashboard links for every Sinch API |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| Skill | What it covers |
|---|---|
sinch-fax-api | Send and receive faxes programmatically |
Below are answers to common questions regarding Agent Skills.
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.
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.
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 for the current list of supported environments.
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.
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 for individual install instructions.
Each skill includes a version field in its frontmatter. The repository is updated as APIs change. Check github.com/sinch/skills for the current version of each skill.
To keep updated automatically, use the Sinch Plugin(s).
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.
Any agent supported by skills.sh is supported by Sinch Skills, including these notable examples:
- Claude Code
- Gemini CLI
- Cursor
- OpenAI Codex
- GitHub Copilot
- OpenCode
- Windsurf
For more information, visit any of the following links:
Skills repository — source of truth for all Sinch skills
Sinch Plugins repository — plugin setup for Claude Code, Gemini CLI, and others
Agent Skills directory — discover and browse Sinch skills
Sinch Dashboard — manage your Sinch account and API keys
Sinch developer documentation — full documentation for every Sinch API