sh

Documentation

Overview

sh is a tiny POSIX shell BIN backed by mvdan.cc/sh/v3/interp. The reason it exists is that openotters' runtime execs each BIN tool as a single process — no kernel shell between the LLM and the binary — so pipelines (`cmd1 | cmd2 | cmd3`) are impossible unless one tool *owns* the pipeline itself. `sh -c "<script>"` is that tool.

Why mvdan's shell rather than busybox:

• pure Go, cross-compiles to every platform our BIN images target (darwin/arm64, darwin/amd64, linux/amd64, linux/arm64) with zero C toolchain.
• embeddable, predictable, no /proc assumptions, no glibc.
• good POSIX coverage for the "pipe commands together" case, which is 99% of why an agent would want a shell.

Limitations worth flagging to the LLM (the Agentfile's BIN block should restate these):

• only the `-c "script"` invocation is supported here; we don't implement REPL or read-from-file modes.
• the mvdan interpreter doesn't support every obscure POSIX feature (job control, terminal operations) — you won't miss anything relevant to tool-chaining.
• the interpreter inherits the host environment and can reach any path the process can. No sandboxing. Treat it as equivalent to giving the LLM shell access on the host.