Claude Code gofmt hook never runs: $CLAUDE_FILE_PATHS is not set (same in conforma/policy) #3601

The PostToolUse hook in .claude/settings.json reads $CLAUDE_FILE_PATHS, which Claude Code doesn't set: the tool call arrives as JSON on stdin, with the path at tool_input.file_path (hooks reference: https://code.claude.com/docs/en/hooks). So f is always empty and gofmt never runs on a file Claude edits.

Fix (needs jq):

"command": "f=$(jq -r '.tool_input.file_path // empty'); case \"$f\" in *.go) gofmt -w \"$f\" 2>/dev/null;; esac"

Tested with the JSON Claude Code sends for an Edit to cmd/main.go: before, nothing runs; after, gofmt -w runs on that file, and a .md edit still runs nothing.

conforma/policy has the same pattern for .rego files, so make fmt never runs there either. The same change works:

"command": "if jq -r '.tool_input.file_path // empty' | grep -q '\\.rego$'; then make fmt 2>/dev/null; fi"

Found this while testing Claude Code hooks for Paveo; uvx paveo doctor flags both. Happy to open a PR in each repo.