strands-cli

The Strands CLI in a box

The Strands CLI, run under a policy on a Mac. It has two tools: the box's shell, and web_fetch, which fetches through the box's egress gateway. So the policy decides every command it runs, every file a command touches, and every host it fetches from. The policy permits no fetch host, so web_fetch is refused until you add one.

Getting started builds these files step by step, and says why each one is there. This directory holds the finished files, so you can copy them and run the box.

Files

• box.toml: what the box runs and what the agent's own process can reach.
• policy.dw: the policy. It permits Bedrock, the shell, reads in the project, and /dev/null.
• proxy-preload.mjs: sends the AWS SDK's requests through the box's egress gateway. Node loads it before the CLI starts.
• strands-home/.strands/cli/config.json: the CLI's settings. The box sets the CLI's HOME to strands-home, and the CLI keeps its sessions and memory there.

Before you start

• A Mac with Apple silicon and macOS 15 or later, and Box in ~/box-tutorial/box-core from getting started.
• Node.js 22.21 or later from Homebrew: brew install node.
• An AWS account with access to Claude Opus 5 on Amazon Bedrock in us-west-2, and a Bedrock API key in AWS_BEARER_TOKEN_BEDROCK, made in us-west-2.

Run it

From ~/box-tutorial:

/opt/homebrew/bin/npm install -g @strands-agents/cli
[ -d my-project ] || { mkdir my-project && echo "# My project" > my-project/README.md; }
[ -d box-src ] || git clone --depth 1 https://github.com/strands-agents/box.git box-src
[ -d strands-cli ] || cp -R box-src/examples/strands-cli strands-cli
sed -i '' "s|<HOME>|$HOME|g" strands-cli/box.toml
./box-core/box run --config strands-cli/box.toml

The box prints what the agent can touch, then the CLI opens a chat. Ask it to read README.md and add a line to it. The box permits the read and refuses the write, because the policy permits only reads. Type /exit to stop the box. Getting started shows how to read the decision log and permit the write.

The paths in box.toml and policy.dw name ~/box-tutorial/my-project as the project, and the paths in box.toml name ~/box-tutorial/strands-cli as this directory. Edit both files to use another project.