# Björn Zethraeus (slim)

> Björn Zethraeus is co-founder of Sinch (founded as CLX Communications). Sinch Messaging APIs + MCP and Sinch Voice API + MCP on Anchor Terminal, with grades, an about and public profiles.

- Full: https://www.anchorterminal.com/people/bjorn-zethraeus/index.md (~850 tokens) · this version ~680 tokens · JSON https://www.anchorterminal.com/people/bjorn-zethraeus/index.json · canonical https://www.anchorterminal.com/people/bjorn-zethraeus/
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-10-28
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)

Co-founder, Sinch (founded as CLX Communications).

## What Björn builds

- [Sinch Messaging APIs + MCP](https://www.anchorterminal.com/tools/sinch.md), graded B, 63.2/100, in Messaging APIs. The SMS REST API and the Conversation API, which sends SMS, RCS, WhatsApp, Viber and Messenger through one message format, plus the Verification API. Co-founder, Sinch (founded as CLX Communications), researched 2026-10-28.
- [Sinch Voice API + MCP](https://www.anchorterminal.com/tools/sinch-voice.md), graded B, 62.7/100, in Phone calling & voice transport. Programmable voice over PSTN, SIP and WebSocket streams, driven by SVAML call-control JSON. Co-founder, Sinch (founded as CLX Communications), researched 2026-10-28.

## Works with

- [Henrik Sandell](https://www.anchorterminal.com/people/henrik-sandell/), Co-founder, Sinch (founded as CLX Communications)
- [Johan Hedberg](https://www.anchorterminal.com/people/johan-hedberg/), Co-founder, Sinch (founded as CLX Communications)
- [Kjell Arvidsson](https://www.anchorterminal.com/people/kjell-arvidsson/), Co-founder, Sinch (founded as CLX Communications)
- [Kristian Männik](https://www.anchorterminal.com/people/kristian-mannik/), Co-founder, Sinch (founded as CLX Communications)
- [Robert Gerstmann](https://www.anchorterminal.com/people/robert-gerstmann/), Co-founder and Chief Evangelist, Sinch

## Questions

### Who is Björn Zethraeus?

Björn Zethraeus is co-founder of Sinch (founded as CLX Communications).

### What does Sinch make?

Anchor Terminal lists Sinch Messaging APIs + MCP and Sinch Voice API + MCP from Sinch.

### How are Björn's tools graded?

Sinch Messaging APIs + MCP is graded B, 63.2 out of 100; Sinch Voice API + MCP is graded B, 62.7 out of 100, on Anchor Terminal's benchmark, which scores every listing against the same checklist.

## Sources

- https://sinch.com/
- https://sinch.com/contact-us/
- https://sinch.com/help-center/
- https://sinch.com/about-us/
- https://www.group.sinch.com/about-sinch/our-history/
- https://en.wikipedia.org/wiki/Sinch_AB

These are the people building the tools we list, named for their public role in the company or project behind a listing, from public pages, with the date it was researched.