Smart Rerouting

When a valid shell command receives natural-language-style arguments and fails, Lacy silently catches it and rerouts to the agent. No user-facing hint — just a second chance.

How it works

Layer 2 post-execution detection runs after a shell command exits with a non-zero code (1–127). Both criteria must match for a reroute:

Error pattern — output contains a known shell error string from LACY_SHELL_ERROR_PATTERNS
NL signal — the second word is in LACY_NL_MARKERS (like the, a, my, this), OR 5+ words with a parse/syntax error

Minimum 2 words required. Only active in Auto mode.

Examples

$kill the process on localhost:3000reroute

No such signal: the → caught, rerouting to AI...

$go ahead and fix the testsreroute

unknown command: ahead → caught, rerouting to AI...

$make sure the tests passreroute

No rule to make target 'sure' → caught, rerouting to AI...

Non-rerouting examples

$kill -9 my-processshell only

Only 2 bare words — below threshold

$echo the quick brown foxshell only

Succeeds — no reroute needed

Implementation

bash

# lib/core/detection.sh
lacy_shell_detect_natural_language "$input" "$output" "$exit_code"
# Returns 0 (NL detected) or 1 (not NL)

The function takes the original input, the command output, and the exit code. It checks both the error pattern and NL signal criteria.

Note

Rerouting only triggers on exit codes 1–127. Exit codes ≥ 128 (signals like SIGKILL) are not rerouted — they indicate something more serious.