calebnewtonusc The Chewbacca runtime: plan, execute, verify, log
For anything longer than a couple of steps, do not freehand a sequence of commands. Compile the request into one formal plan, check it, run it, and read the trace.
The reason is arithmetic, not style. Twenty improvised steps at 95% reliability each
is a 36% success rate (see docs/BENCHMARKS.md). A checked plan that stops at the
first failure and gates every irreversible action does not compound errors that way.
This is the Genie / executable-semantic-parser idea (Campagna, Xu, Lam; Liang):
compile intent into a typed, checkable representation that runs or errors cleanly,
rather than letting the model improvise.
The grammar
data/grammar.json defines the command space: stream => query* => action*.
- stream - when it runs:
now,every,on_text,on_file,on_calendar - query - reads, no side effects:
texts,screen,web,app_data,file - action - side effects:
click,type,web_click,web_fill,remind,calendar,send_text,send_email,run_shell
Every parameter is typed. Every irreversible action carries confirm: true in its
signature, so the gate is part of the type and cannot be forgotten.
Write a plan
{
"stream": { "name": "now" },
"query": [{ "name": "texts", "days": 2, "unanswered": true, "direct": true }],
"action": [{ "name": "remind", "title": "Reply to Chen about Saturday" }]
}
Run it
chewie plan check plan.json # type-check only, runs nothing
chewie plan run plan.json # execute; confirm-gated actions refuse without --yes
chewie plan run plan.json --yes
check catches a missing or mistyped parameter before anything touches the machine.
run executes queries then actions in order, stops at the first failure, and writes
a trace.
Read what happened
chewie log # the last run, step by step, with timing
chewie log --runs # recent runs
chewie log --json # the raw trace
Every step is logged with its status and duration to ~/.chewie/runs/<ts>.jsonl. When
a task half-worked, this is how you find the step that failed instead of guessing.
When NOT to use a plan
A single read (chewie see, chewie texts, chewie brief) or a single obvious action does
not need the ceremony. The plan runtime earns its keep on multi-step tasks, on anything
irreversible, and on anything the user will want to audit afterward.
The end-to-end pattern
The headline example - research leads, draft outreach, stage, confirm - is one plan:
now
=> web (query LinkedIn / a directory for companies under 50 employees)
=> web (extract contact emails)
=> send_text (text the user the list) [confirm]
=> send_email (staged drafts, one per lead) [confirm]
The two outbound steps are confirm: true, so Chewbacca compiles and stages the whole
thing, then stops and shows the user exactly what it will send before a single email
leaves. That gate is in the grammar, not bolted on, which is why it holds even under
"just send them, I trust you."