dsh-units 📐
Unit conversion toolbox for DeepSeek Harness (dsh) — 22 categories, 3 tools, zero runtime dependencies, pure arithmetic over a static unit table (no network, no filesystem, no code execution).
When your agent needs to answer "how many miles is 100 km?", "is 1 MB bigger than 1 MiB?", "is 100 Mbps the same as 100 MB/s?", "what's 350°F in Celsius?", "how many tablespoons in 2 cups?", "16px is how many pt?", "20 mpg in L/100km?", "150 kW is how much mechanical horsepower?", "how many g is 9.8 m/s²?", "100 CFM in m³/h?", "is $3.99/lb cheaper than $8.50/kg?" or "500 g for $4.29 vs 1 lb for $3.59?" — instead of doing error-prone mental math, it can call these tools and read exact results.
中文简介：dsh-units 是 DeepSeek Harness 的单位换算工具箱插件，覆盖长度、质量、温度、面积、体积（含美制烹饪单位）、速度、时长、数据大小（十进制 MB 与二进制 MiB 严格区分）、数据传输速率（Mbps 与 MB/s 严格区分）、加速度（g-force）、照度（lux / 英尺烛光）、压强、能量、角度、频率、功率（机械/公制/电动马力严格区分）、力、扭矩、排版印刷（px/pt/em/rem）、体积流量（m³/s、L/min、CFM、US gpm）、密度（kg/m³、g/cm³、lb/ft³、lb/gal）、油耗（L/100km ↔ mpg ↔ km/L）共 22 个类别，并提供单价归一与比价工具，零运行时依赖、纯算术实现，无网络无副作用。让 Agent 不再心算——特别是"MB/MiB 混淆""100 Mbps 不等于 100 MB/s""华氏摄氏互转""加仑换升""mpg 与 L/100km 互算""三种马力混淆""$3.99/lb 与 $8.50/kg 哪个便宜"这类高频出错点，直接调用工具拿精确结果。
Why it exists
- LLMs are unreliable at unit math. Temperatures are affine (offset), data sizes mix decimal and binary prefixes, fuel economy is reciprocal (mpg vs. L/100km), and compound units (km/h, psi, kcal) hide awkward factors. A wrong conversion silently corrupts reports, recipes, travel plans, and capacity math.
- Fully deterministic and offline. Every factor lives in the static table in
src/units.ts — no API keys, no lookup services, nothing to drift.
- Structured results. Each conversion returns the original value, both units (symbol + full name), the result, the formula applied, and the category — so the agent can explain its math instead of just asserting it.
Tools
| Tool | What it does |
|---|
convert_unit | Convert value from one unit to another within a category. Accepts symbols or full names (case-insensitive, °C, m², "miles", "MiB" all work). Rejects unknown units and cross-category pairs with clear errors. |
list_units | List all 22 categories with every unit symbol and full name (optionally one category, e.g. "data" or "temperature") — for discovering the exact symbols to pass to convert_unit and unit_price. |
unit_price | Normalize and compare unit prices: pass 1–6 offers as { price, per, quantity? } (quantity defaults to 1, so { price: 4.29, per: "g", quantity: 500 } is a 500 g pack) and get the price of one target unit for each offer (default: the category base unit), the cheapest offer and the spread in percent. Rejects temperatures (affine) and fuel economy (reciprocal) instead of returning a meaningless number. |
unit_sum | Add up 1–12 quantities that share one category, each in its own unit, and get the total and the mean in a target unit (default: the category base unit). Built for "5 ft 3 in + 1.2 m + 80 cm" and "1 h 30 min 45 s" without mental conversion: every quantity is converted to the base unit and summed with compensated (Neumaier) accumulation, so a long list of small addends does not drift. Negative values are allowed, so it answers differences too. Rejects temperatures (affine) and fuel economy (reciprocal). |
Supported categories
| Category | Units (symbols) |
|---|
| length | km, m, cm, mm, um, nm, in, ft, yd, mi, nmi |
| mass | t (metric tonne), kg, g, mg, lb, oz |
| temperature | c, f, k — affine conversion with offsets |
| area | km2, ha, m2, cm2, mm2, mi2, acre, yd2, ft2, in2 |
| volume (incl. cooking) | m3, l, ml, cm3, gal, qt, pint, cup, floz, tbsp, tsp (US units) |
| speed | km/h, m/s, mph, knot, ft/s |
| time duration | yr (Julian, 365.25 d), wk, d, h, min, s, ms |
| data size | tbit…bit, pb…b (decimal), pib…kib (binary) — MB ≠ MiB |
| data transfer rate | tbit/s…bit/s (decimal bits), tb/s…b/s (decimal bytes), tib/s…kib/s (binary bytes) — 100 Mbps = 12.5 MB/s |
| acceleration | m/s2, g0 (standard gravity 9.80665 m/s²), ft/s2, mph/s — g-force & automotive |
| illumination | klx, lx (lux), fc (foot-candle), ph (phot) — 1 fc = 10.76391 lx |
| pressure | mpa, kpa, bar, atm, psi, mmhg, torr, pa |
| energy | kwh, wh, kcal, kj, cal, j, ev |
| angle | deg, rad, grad |
| frequency / rotation | ghz, mhz, khz, hz, rpm |
| typography (CSS / print) | px, pt, pc (pica), em, rem — 96 dpi reference, 16 px base font for em/rem |
| fuel economy | l/100km, l/km, mpg (US), mpg(uk) (imperial), km/l — reciprocal, mpg ≠ linear |
| power | mw, kw, w, hp (mechanical = 550 ft·lbf/s), hp(m) (metric PS), hp(e) (electric 746 W), btu/h (IT), ftlb/s — three different horsepower definitions |
| force | kn, n, dyn, lbf, kgf (kp), gf — lbf/kgf are weight-based at standard gravity 9.80665 m/s² |
| torque | n.m, kgf.m, lbfft (pound-force foot), lbfin (pound-force inch) — force × length |
| volumetric flow rate | m3/s, m3/h, l/s, l/min, l/h, cfm (cubic foot per minute), gpm (US gallon per minute) — flows, not volumes |
| density | kg/m3, g/l (identical to kg/m³), g/cm3 (= g/mL = kg/L = t/m³), g/ml, kg/l, t/m3, lb/ft3, lb/gal — lb/gal is 119.8264 kg/m³ |
v0.2.0 note: pt now means the typography point (previously the US pint). Use pint for pints — convert_unit { value: 1, from: "pint", to: "l" } still works. em/rem assume the common 16 px browser default base font size; px assumes 96 dpi (documented assumptions, not physical absolutes).
v0.3.0 note (symbol disambiguation): typed input kn resolves to knot (speed) — reach kilonewton by its full name (convert_unit { value: 1, from: "kilonewton", to: "n" }). Likewise nm is the nanometer (length); the torque newton meter uses the symbol n.m (also n·m or full names).
v0.4.0 note (category split & disambiguation): the old data size / transfer category is now data size (sizes only); rates live in data transfer rate — mb/s means megabyte per second (following mb = megabyte in the data table), while mbps / mbit/s mean megabit per second, so 100 Mbps → 12.5 MB/s exactly. In acceleration, typed g stays the gram (mass) — gravity is g0 / gravity / g-force; gal stays the US gallon (no galileo unit); ph is the phot, not pH.
v0.5.0 note (flow rate, density, unit prices): two new categories — volumetric flow rate (m3/s, m3/h, l/s, l/min, l/h, cfm, gpm; a flow is not a volume, so l/min will not convert to l) and density (kg/m3, g/l, g/cm3, g/ml, kg/l, t/m3, lb/ft3, lb/gal). One new tool — unit_price — normalizes 1–6 offers onto one target unit and ranks them; it deliberately rejects temperature (affine zero point) and fuel economy (reciprocal), and every offer must share a category with the others and with to.
Install
dsh plugin --profile default add github:TYEclipse/dsh-units
or clone and build locally:
git clone https://github.com/TYEclipse/dsh-units.git
cd dsh-units && pnpm install && pnpm build
Usage
The agent just calls the tools — no setup beyond installation:
convert_unit { value: 100, from: "km", to: "mi" }
→ 100 km = 62.137119 mi (length, × 0.621371192237334)
convert_unit { value: 500, from: "MiB", to: "MB" }
→ 500 mib = 524.288 mb (data size, × 1.048576)
convert_unit { value: 100, from: "Mbps", to: "MB/s" }
→ 100 mbit/s = 12.5 mb/s (data transfer rate, × 0.125)
convert_unit { value: 350, from: "fahrenheit", to: "celsius" }
→ 350 f = 176.666667 c (temperature, (x − 32) × 5/9)
convert_unit { value: 16, from: "px", to: "pt" }
→ 16 px = 12 pt (typography (CSS / print), × 0.75)
convert_unit { value: 20, from: "mpg", to: "l/100km" }
→ 20 mpg = 11.760729 l/100km (fuel economy, 235.214583 ÷ x → x)
convert_unit { value: 150, from: "kw", to: "hp" }
→ 150 kw = 201.153313 hp (power, × 1.3410220895950278)
convert_unit { value: 1, from: "lbfft", to: "n.m" }
→ 1 lbfft = 1.355818 n.m (torque, × 1.3558179483314003)
convert_unit { value: 9.8, from: "m/s2", to: "g0" }
→ 9.8 m/s2 = 0.999322 g0 (acceleration, × 0.10197162129779283)
convert_unit { value: 1, from: "fc", to: "lx" }
→ 1 fc = 10.76391 lx (illumination, × 10.763910416709722)
convert_unit { value: 1, from: "gpm", to: "l/s" }
→ 1 gpm = 0.0630902 l/s (volumetric flow rate, × 0.0630901964)
convert_unit { value: 100, from: "cfm", to: "m3/h" }
→ 100 cfm = 169.90108 m3/h (volumetric flow rate, × 1.6990107955200004)
convert_unit { value: 1, from: "lb/ft3", to: "kg/m3" }
→ 1 lb/ft3 = 16.018463 kg/m3 (density, × 16.018463373960138)
unit_price { offers: [{ price: 3.99, per: "lb" }, { price: 8.5, per: "kg" }], to: "kg" }
→ unit prices per kg (mass):
#1 3.99 per lb → 8.796444 per kg
#2 8.5 per kg → 8.5 per kg
cheapest: #2 at 8.5 per kg (spread 3.370046%)
unit_price { offers: [{ price: 4.29, per: "g", quantity: 500 }, { price: 3.59, per: "lb" }], to: "kg" }
→ unit prices per kg (mass):
#1 4.29 per g (500 g) = 0.5 kg → 8.58 per kg
#2 3.59 per lb → 7.914595 per kg
cheapest: #2 at 7.914595 per kg (spread 7.755301%)
unit_sum { items: [{ value: 5, unit: "ft" }, { value: 3, unit: "in" }, { value: 1.2, unit: "m" }, { value: 80, unit: "cm" }], to: "cm" }
→ sum of 4 quantities: 5 ft + 3 in + 1.2 m + 80 cm = 360.02 cm (3.6002 m); mean 90.005 cm
unit_sum { items: [{ value: 1, unit: "h" }, { value: 30, unit: "min" }, { value: 45, unit: "s" }] }
→ sum of 3 quantities: 1 h + 30 min + 45 s = 5445 s; mean 1815 s
list_units { category: "volume" }
→ volume (volume (incl. cooking), base: liter): m3 = cubic meter | l = liter | ...
list_units { category: "flow" }
→ flow (volumetric flow rate, base: cubic meter per second): m3/s = cubic meter per second | ... | gpm = US gallon per minute
All outputs above are captured from the built dist/ (v0.6.0).
Configuration
plugins:
dsh-units:
maxDecimals: 6 # display rounding: decimals ≥ 1, significant digits below (1–12)
Safety model
- Pure math. No network, no filesystem access, no subprocesses, no code execution.
- Strict input validation. Unknown units, cross-category pairs, and non-finite values throw descriptive errors instead of returning garbage.
- Display-only rounding. Internal computation keeps full float precision; rounding applies to the returned
result only.
- No opinions about validity. Converting
-10 K returns the arithmetic result; physical plausibility is the caller's business (documented so agents don't over-trust the tool).
Development
pnpm install
pnpm build # tsc, strict
pnpm test # vitest, fully offline fixtures
pnpm lint # oxlint (src + test only)
License
MIT © 2026 TYEclipse
