Don’t make the model pay 200 lines to find a function
Coding agents still read like find | cat: dump the tree, grep wide, page 200-line windows until context is landfill. Codeloom’s engine makes reading a cost hierarchy, then puts TypeSafe System One (jev-latest) on a few choke points.
The LLM generates. TypeSafe (JEV) judges. Code decides.
JEV never writes a query, invents a path, or authors an edit.
Who reads
The user talks to the orchestrator. It has no list_files / search / read_file. ask is the reader. coder read_files before an edit — that is a write-funnel stamp, not discovery.
Cheaper-first ladder
Prompt policy, not a hard state machine. Tool descriptions push the same order.
| Step | Tool | Cost | Why it exists |
|---|---|---|---|
| Locate | search |
rg, 10s cap, skip-dirs | Prefer this over listing |
| Locate (last) | list_files |
flatten whole tree | Model tends to dump; prompt says don’t |
| Outline | list_symbols |
one parse, no LSP | See a file without reading it |
| One def | find_symbol |
same parse | Body + coordinate handoff |
| Local CST | query_tree / get_node_at / parse_file |
instant | Imports, calls, nesting |
| Types | LSP | server wait | Cross-file truth; fall back to sitter |
| Context | read_file |
200–400 numbered lines | Surrounding source + write stamp |
coder: skip search. Read the briefing’s paths. Search once only if a path is missing.
JEV in one table
~100ms calibrated classifier. One state + N parallel questions. Missing key / timeout / 5xx → None → pre-judge path. Engine works without it.
| Primitive | Returns | Read-path use |
|---|---|---|
Noul |
P(yes) 0–1 | injection? answers the question? |
Choice |
option + per-option P | which rg hit? what intent? |
Score |
ordinal | mostly exec blast radius, not reads |
Judgments only add restriction or information. They never override guard_write_path, the syntax gate, staleness, or the write denylist.
Modes: off / advisory (events only) / enforcing. Per-site overrides (ENGINE_JUDGE_SEARCH, _SCREEN, _INTENT, …). Write gate does not inherit a blanket enforcing.
Judged read path
Child reports ([agent ask … finished]) skip this. Injecting search into orch history — orch has no FS tools — stalled the model.
Four call sites on reads
| Tag | When | Question | Enforcing effect |
|---|---|---|---|
intent_route |
before the loop | meta / locate / edit / execute | skip loop, or bump turns |
search_rerank |
rg hits > 10 | which line answers the query? | return top 15, not 80 |
intent_route (gate) |
after 2 windows | does gathered context answer it? | seed history or fall through |
call_verify |
LSP / edits, not search/read | coords from find_symbol? path was read? |
error string, don’t run |
result_screen |
large tool results | instruction / override / secrets / ordinary code? | flag wrap, or redact secrets |
list_files is never verified or screened. Cheap to get wrong, cheap to retry.
Search re-rank
One Choice scores every candidate. A lexical miss that the model then read_files is 200 lines and a round trip.
Result screen
| Signal | Role |
|---|---|
contains_instruction_to_agent |
hazard |
attempts_override |
hazard |
requests_secret_disclosure |
redact if high |
is_ordinary_source_code |
false-positive brake |
This repo is full of prompt strings. Hazard high and ordinary low → wrap, don’t strip. Only the first 4k chars are judged.
read_file itself
Edit without that stamp: error: read X before editing it. Sha drift: read again.
Other personalities
| Profile | First read |
|---|---|
| ask | Full ladder |
| coder | read_file named paths |
| debugger | Same NAV + shell/git/browser. Don’t stop at the first filename. |
| reviewer | git_diff in the writer’s worktree, then sitter/LSP on changed files |
| researcher | Remote first. Workspace search only after external facts |
| tester | Read code under test, then write tests |
Pros
| Right model for a choke point | Classifier over closed sets. Cannot hallucinate a path. |
| Restriction-only | Cannot punch through deterministic write/exec guards. |
| Optional | No key / None verdict = old behaviour. Tests assert that. |
| Search re-rank is asymmetric | ~100ms vs N wasted read_files. Biggest quality-per-turn lever. |
| Screening closes a real hole | File contents and stdout used to enter context unscreened (80k cap). |
| Locate can delete 5–6 tool rounds | Model still writes the answer; it skips exploration. |
| Decisions are code | Thresholds in judge_decisions.py. Pure functions. Tunable. |
| Observable | JudgementMade: tag, signals, enforced?, latency. |
Cons
| Not ground truth | Parser/LSP beat a probability on syntax and types. |
| Cannot generate queries | Locate pattern = stopword-stripped identifiers. “How does auth work?” may miss authenticate. |
| Confidence compounds | 0.9⁴ ≈ 0.66. Resolver stopped before list_symbols → find_symbol. Fall through often, be right when you don’t. |
| Latency vs the brochure | Timeout 800ms. Screen fires on every large result. Fall-through pays classify and still runs ask. Advisory pays for nothing. |
| False positives already happened | git status scored as huge blast radius (it observes the repo). Prompt files need the ordinary-code brake. Thresholds are first guesses. |
| Orch / resolver clash | Orch has no FS tools. Seeding search into orch already stalled a turn. Inbox handoffs had to be excluded. |
| Knob sprawl | Global mode + ~10 site overrides. Write gate refuses to inherit enforcing. Correct, and not “turn the judge on.” |
| Extra vendor on the hot path | Key, cost, 800ms tail of no-ops. Cache (512) helps re-reads, not first reads. |
| Gaps on the read path | No list_symbols re-rank. Verify does not run on search/read_file. JEV will not stop list_files first — that’s still a prompt. |
| Screen is windowed | Injection after char 4000 is out of scope. |
The split worth keeping
| Enumerable (JEV can pick) | Not enumerable (LLM must generate) |
|---|---|
read_file given a known path |
search query |
find_symbol given a name from the outline |
str_replace / patch body |
goto_definition given find_symbol coords |
run_command |
Navigation can stop being an agent. Editing cannot.
Ship each site advisory until the false-positive rate is a number. Let JEV reorder rg and flag hostile bytes. Do not let it invent the next path.
About the author
- Engineering building native Voice infra for salesforce by day, and hacking around awesome products by night
Comments
Join the discussionIs the hierarchy fixed, or does it learn which reads were worth the tokens? Run it against a few repos and watch whether the cheap path stays cheap when the codebase is messy.
Multi agent handoffs fail when the contract is fuzzy. I write the handoff as a typed payload with owner and done criteria. Chatty freeform between agents burns tokens and trust.
