Introducing Sinch Skills: Expert Sinch API knowledge, right inside your AI Coding Agent

AI coding agents like Claude Code, Gemini CLI, and Cursor help you ship faster. But these agents are only as good as the context they have, and they often break when building with complex APIs. The agent isn’t the problem. It just needs the right knowledge.

That’s why we built Sinch Skills – 17 structured knowledge files that give your AI coding agent expert-level context for every Sinch API. Install once, and your agent handles the rest.

Generic AI training data gets you close to production-ready code, but “close” isn’t good enough.

When developers use AI agents to build with Sinch APIs today, they run into predictable problems:

• Auth methods vary by API. Application Key and Secret is required for Verification — not project OAuth2. Agents get this wrong constantly.
• Regional endpoint rules for Conversation API, Voice, and SIP Trunking are not documented in a way agents easily pick up.
• Agents often retry billable actions, like number provisioning, without first verifying the action’s state, leading to unnecessary charges.
• Async flows — webhook setup, processing modes, campaign approval — require sequencing that agents have to guess at without guidance.

As a result, they spend a lot of time fixing agent output instead of shipping.

Sinch Skills are structured files your AI coding agent reads as context, helping developers avoid the common problems of AI-generated API integrations.

Each skill is a directory containing a SKILL.md file with everything the agent needs to work with a specific Sinch API, including:

• Auth setup
• Getting-started code
• Key concepts
• Common patterns and gotchas
• Links to the full API reference

Skills follow the Agent Skills open standard, which means they work with any tool that supports SKILL.md files — Claude Code, Gemini CLI, Cursor, Codex, GitHub Copilot, Windsurf, and others.

Skills use progressive disclosure so they don’t overwhelm your agent’s context window.

1. Your agent starts by loading only the name and description of each skill. This tells it what knowledge is available.
2. When a task matches a skill, the agent reads the full SKILL.md and any referenced scripts or assets.
3. Your agent generates code guided by real Sinch expertise, not training data guesswork.

It’s deep knowledge, delivered exactly when your agent needs it.

We’re launching with coverage across every major Sinch product area:

Each skill goes beyond API examples. They include the real-world patterns, sequencing, and edge cases that make the difference between code that demos and code that ships.

A few examples of what that looks like in practice:

• The 10DLC skill covers the full six-step registration workflow, including why vague campaign descriptions get rejected by TCR and why you should always use FULL registration type for production.
• The Verification skill leads with the auth pattern developers get wrong most often: Application Key and Secret, not project OAuth2.
• The Voice skill covers that cli is required for TTS callouts to connect, that instruction order in SVAML matters, and that ACE callbacks are not sent for in-app destinations.

We’ve packaged years of our team’s knowledge for your agent.

Great developer experience used to be clear docs, good SDKs, and fast onboarding. Those things still matter. But now, a developer’s job is often to direct an agent that does the implementation.

That shift changes what “good developer experience” means. It’s not enough to have documentation a human can read. The knowledge has to be in a form an agent can use — structured, opinionated, scoped precisely.

Sinch Skills is our answer to that. We want your agent to behave like a Sinch expert developer: knowing the right patterns, catching the common mistakes, generating code you can trust.

npx skills add sinch/skills

This command adds all 17 skills to your agent’s environment. You can also install skills individually or set them up from the Sinch Plugins repository if you prefer.

Skills are free and open source under Apache-2.0. You need a Sinch account to use the APIs the skills describe — sign up at dashboard.sinch.com.

Browse the full skills library at github.com/sinch/skills.

This is the beginning. We’ll be continuously updating skills as APIs evolve and expanding coverage based on what developers actually build. If you have feedback or want to contribute, the repo is open — pull requests welcome.

Author: The Sinch team