Project
Open source
Apache-2.0, one maintainer, pre-1.0, no users yet. Here is how to check every claim on this site yourself.
The licence
Apache-2.0, all of it — the runtime, the tools, the CLI and this site. No commercial-use restriction, no source-available licence with a catch in clause four, no separate enterprise build with the interesting features in it.
Project status
The useful thing I can offer instead of adoption numbers is a plain statement of where the project actually is, and evidence you can check yourself. Both are below.
Licence
Apache-2.0 for all of it — no commercial-use restriction, no source-available catch.
Apache-2.0Published to npm
Yes, as of the 0.1.0 release this site ships alongside: npm install -g arcturn. Building from a clone still works and is how you run an unreleased commit.
0.1.0Version
Pre-1.0. APIs may change between releases, and some of them will.
Pre-1.0Maintainers
One person, working on it in the open. Issues and pull requests are welcome.
OneProduction users
None that I know of. There are no adoption numbers to show you, so there are none here.
NoneProven provider paths
Anthropic, Google, OpenAI on both its Chat Completions and Responses surfaces, and both compatibility adapters — each driven against a live endpoint through streaming, a tool call answered on a second turn, and cost accounting checked against published rates. Bedrock, Vertex and Azure are implemented but have never reached an endpoint.
Six
Verify it yourself
Run these, don’t take my word for it. Every number this project could quote about itself moves with every commit, so the commands are the claim — clone the repository and see what they print on main today.
The same applies to the security page: every limit listed there is a property of code you can read, and every fix from the adversarial-review waves landed with a regression test verified to fail against the previous behaviour first. Those tests are in packages/*/src beside what they cover.
find packages -name "*.test.ts" | wc -l # test files
grep -rE "^ +(it|test)[.(]" packages | wc -l # test cases
ls packages # the package listContributing
Issues and pull requests on GitHub. There is no CLA. You need Node ≥ 20 and pnpm ≥ 10; the monorepo is a pnpm workspace, so a build is pnpm install then pnpm build.
pnpm check runs lint and typecheck, pnpm test runs the suites. A change that touches a safety control is easiest to review when it arrives with the regression test that fails without it.
git clone https://github.com/sitharaj88/arcturn.git
cd arcturn
pnpm install
pnpm build # build all packages
pnpm check # lint + typecheck
pnpm test # run all testsAuthor & support
Sitharaj Seenivasan
Arcturn is built and maintained by one person. If it is useful to you, the links below are the ways to say so.
Every turn counts.
Start a session, watch every tool call ask first, then go back and read exactly what happened.