Agent fails to spawn `claude` on Windows when the CLI is installed via npm (`.ps1`/`.cmd` shim)

[mthelm85]

On Windows, an npm-installed Claude Code CLI provides claude.ps1 / claude.cmd shims on PATH rather than an .exe. Kaimon's agent service spawns `claude -p ...` directly, and libuv/Base.run only resolves real executables — so opening the agent fails with:

Error opening agent: IOError: could not spawn setenv(`claude -p --input-format stream-json ...`): no such file or directory (ENOENT)

...even though claude --version works fine in the user's shell.

Installing the native build (irm https://claude.ai/install.ps1 | iex, which drops claude.exe into ~/.local/bin) fixes it.

Suggestions (any subset):

• Detect the situation: if spawning fails and Sys.which("claude") === nothing while a claude.cmd/claude.ps1 exists on PATH, raise a clear error telling the user to install the native CLI.
• Or spawn via cmd /c claude ... on Windows when only a shim is present.
• Docs: note that on Windows the native installer is required for the agent.

Also worth noting: the ENOENT error message currently dumps the entire environment block (including any API keys in the user's environment) into the UI — trimming that would avoid accidental secret leaks when users paste errors into issues.

[kahliburke]

Ah Windows ... ;) will try to take a look in a few days.

[kahliburke]

Fixed by #66 (merged to main; ships in the next release — it landed just after the 2.0.8 bump, so it'll be in 2.0.9, not 2.0.8).

Root cause (thanks for the sharp report — and for pinpointing the shim angle): on Windows, Sys.which resolves a bare command name only as .exe — it ignores PATHEXT entirely. So an npm-installed claude (a .cmd + .ps1 shim, no .exe) is invisible to Sys.which, and thus to Base.run/libuv, which ENOENTs — even though claude --version works in your shell. Confirmed on a fresh Windows instance: Sys.which("claude") returns nothing while Sys.which("claude.cmd") resolves fine.

Two fixes:

1. Shim resolution — launch_argv now falls back to a PATH × PATHEXT search when Sys.which comes up empty, finds the .cmd/.ps1, and wraps it through its interpreter (cmd.exe /d /c / powershell -File) as before. So the npm CLI works directly — the native installer is no longer required. Covers every CLI spawn (claude/gemini/codex MCP commands and the agent). Verified end-to-end on real Windows: bare claude → resolved to the .cmd → wrapped → spawns with args passed through.

2. The secret leak (the important note at the bottom of your report) — a failed spawn's IOError stringified the whole setenv(cmd, env), including the process environment, surfaced verbatim in the UI. Fixed: spawn failures now re-raise a sanitized error built from the argv alone (no env), with an actionable hint. No more dumping ANTHROPIC_API_KEY into a pasteable error.