lemonwrench

🔧 LemonWrench

A skill for AI coding agents — Claude Code, Hermes, or any harness that reads SKILL.md — that turns a car into a procedure, a torque table, and labelled figures, from free OEM service manuals.

You drop the folder in, and your agent gets a lookup procedure plus a stdlib script for a free service-manual site. Ask it "rear valve cover torque on a 3.9L" and it comes back with the steps, the numbers and the manual's figures. The script runs on its own too if you don't use an agent.

Named for lemon-manuals.la, the source it scrapes: ~10,000 US/Canada vehicles, 1960–2025, free, no login. Two databases per year — a 2025 capture (LEMON) for modern cars and 2013 DVD dumps (CHARM) for 90s/2000s, which still carry the finer detail.

👉 See the example output — a full job note

2007 Pontiac G6 GT 3.9L valve cover gaskets: both sides step-by-step, a 20-fastener torque table, the blocking bracket identified from a parts catalog, 19 captioned manual figures, and a confidence column that separates what the manual says from what mechanics say — with all 19 of the manual's figures committed alongside it.

$ python3 scripts/lemon.py index "Pontiac/2007/G6 V6-3.9L"
indexed /Pontiac/2007/G6%20V6-3.9L/Repair%20and%20Diagnosis/ (2825 KB)
7520 pages indexed -> ~/.cache/lemon/e031f9347485c7e8.idx

$ python3 scripts/lemon.py torque "Pontiac/2007/G6 V6-3.9L" valve cover -p 1
## Valve Rocker Arm Cover Replacement - Left Side
https://lemon-manuals.la/Pontiac/2007/G6%20V6-3.9L/.../Valve%20Rocker%20Arm%20Cover%20Replacement%20-%20Left%20Side/
Tighten the bolts to 10 N.m (89 lb in).

Coverage — 1960 to 2025, 69 makes, ~10,000 vehicles

Your car is almost certainly in here. Domestic, import, dead brands, exotics, work trucks, EVs.

Years per make go deep, not just recent: Toyota and Ford cover 66 straight model years (1960–2025), Honda from 1969, Pontiac through the 2010 shutdown, Tesla from its first Model S.

Two-minute test for any car:

python3 scripts/lemon.py cars Ford 1997 | head          # is my year covered?
python3 scripts/lemon.py cars "Dodge and Ram" 2004      # exact trim/engine variants

Every hit is tagged [LEMON] (2025 capture) or [CHARM] (2013 DVDs) — different books, different detail, both free.

Why it exists

Generic web search gives you a forum thread from 2011 with a broken Photobucket link. The manual gives you the procedure but omits the thing that actually stops the job — the bracket nobody documented that covers one bolt. LemonWrench runs both, plus a parts catalog, and tells you which claim came from where.

The three-source rule: manual → parts catalog → field consensus. If they disagree, the note says so instead of picking a favourite.

What's in the box

Install

Any agent that loads SKILL.md-style skills (Hermes, Claude Code, etc.) — drop the directory in your skills folder:

git clone https://github.com/bpawnzZ/lemonwrench.git ~/.myagent/skills/lemonwrench

Or just use the script directly:

python3 scripts/lemon.py makes
python3 scripts/lemon.py years Honda
python3 scripts/lemon.py cars Toyota 2015
python3 scripts/lemon.py index "Toyota/2015/Camry LE"
python3 scripts/lemon.py find "Toyota/2015/Camry LE" "fluid capacities"
python3 scripts/lemon.py read "Toyota/2015/Camry LE" "capacity"
python3 scripts/lemon.py torque "Toyota/2015/Camry LE" brake

Stdlib only, Python 3.9+. No API key, no browser, no dependencies. Cache lives in ~/.cache/lemon/, so the second question about the same car is instant — the link index and fetched pages both cache (7 days; LEMON_TTL seconds overrides, LEMON_NOCACHE=1 skips, index --refresh rebuilds the tree).

The trick

Fetching a whole manual is slow; the site splits everything into thousands of pages. So index the link tree once (~5 MB, cached), then find is a local grep and read fetches only the winning page — plus, on CHARM, auto-descends the hub pages whose trees are cut off at depth.

python3 scripts/lemon.py find "Chevrolet/2007/Impala V6-3.9L" generator bracket   # local grep
python3 scripts/lemon.py sub  "https://lemon-manuals.la/.../Alternator/"          # reveal children
python3 scripts/lemon.py get  "https://lemon-manuals.la/.../Service%20and%20Repair/"

If the host is slow or down, fetches retry with a backoff and then fail over to a mirror on their own.

Figures

Manuals are full of exploded views with torque callouts the prose never mentions. pic downloads a figure to disk, the agent looks at it, and note stores the description permanently — describe a diagram once, and it's text in every later session.

python3 scripts/lemon.py pic  https://lemon-manuals.la/images25/GM1557668/
python3 scripts/lemon.py note https://lemon-manuals.la/images25/GM1557668/ "right rocker cover: 6-bolt ring, coil bracket above, MAP connector"

Example output

examples/2007-pontiac-g6-3.9l-valve-cover-gaskets.md — a real job note, rendered with its figures: blocking bracket identified, 20-fastener torque table, both sides in order, captioned exploded views, and a confidence column separating what the manual says from what mechanics say.

cd examples && ./fetch-figures.sh    # re-pull or refresh the figure set

Notes

• Figures ship with the example (19 scans) and can be refreshed anytime with examples/fetch-figures.sh.
• Mirrors, if the main host is down: lemon-manuals.org.ua, lemon-manuals.gy, lemon.dogeware.me — used automatically; set LEMON_BASE to pin one host instead.
• The skill is source-agnostic in method: swap the manual site and the three-source rule still applies.
• Be a good citizen: the cache exists so one session touches the site a handful of times, not hundreds. Don't disable it to crawl.

MIT.