Developers

Documentation

Integrate EngiToolbox into your own tools — REST API, MCP for AI assistants, or the CAM Studio G-code API below.

Calculator API

Every engineering calculator is available as a JSON REST endpoint. Authenticate with an API key to validate designs, batch-run calculations, and embed engineering maths in your software.

API reference OpenAPI spec

MCP (AI assistants)

Connect EngiToolbox to Cursor, Claude Desktop, and other MCP clients. Every calculator becomes a tool your AI can call — requires a Pro+ API key.

Setup guide

CAM Studio G-code API

Parse and lift G-code, run multi-step operation pipelines, transform contours and pockets, generate drilling cycles, and recommend speeds & feeds. Requires a CAM Studio subscription.

API reference OpenAPI spec

Calculator API — Quickstart

Create an API key from your dashboard (requires a Pro or Team plan), then call any endpoint with your key in the Authorization header:

curl -X POST https://engitoolbox.org/api/v1/stress \
  -H "Authorization: Bearer et_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{"force":1000,"area":0.01}'

Responses use a consistent envelope: { ok, calculator, version, inputs, result }. Errors return { ok: false, error, details? }.

Authentication & rate limits

Pass Authorization: Bearer et_…. Each key is bound to your plan. Requests are limited to a short-term burst (per key) and a monthly quota:

Plan	Price	API requests / month
Free	Free	No API access
Pro	Paid — see pricing	1,000
Team	Paid — see pricing	10,000
Enterprise	Custom	100,000

Exceeding the burst or monthly quota returns HTTP 429. See pricing for full plan details.

Endpoints (35)

Electrical

POST/api/v1/capacitor-network— Capacitor network
POST/api/v1/resistor-network— Resistor network
POST/api/v1/voltage-divider— Voltage divider
POST/api/v1/rc-time-constant— RC time constant
POST/api/v1/led-resistor— LED ballast resistor

Manufacturing

POST/api/v1/drill-point-depth— Drill point depth
POST/api/v1/speeds-and-feeds— Machining speeds & feeds
POST/api/v1/pcd— Pitch circle diameter hole coordinates
POST/api/v1/punch-die-clearance— Punch & die clearance
POST/api/v1/limits-and-fits— ISO limits & fits
POST/api/v1/bolt-torque— Bolt torque & preload
POST/api/v1/thread-engagement— Thread engagement & tap drill
POST/api/v1/thread-reverse-engineering— Thread reverse engineering
POST/api/v1/gcode-drilling— Drilling cycle G-code generator

Math

POST/api/v1/trigonometry— Right-triangle solver

Mechanical

POST/api/v1/stress— Axial / normal stress
POST/api/v1/friction— Friction force
POST/api/v1/centrifugal-force— Centrifugal force
POST/api/v1/bearing-life— Bearing life (L10)
POST/api/v1/bearing-load— Equivalent bearing load
POST/api/v1/bearing-rating— Dynamic & static ratings from geometry
POST/api/v1/plain-bearing— Plain bearing PV & wear
POST/api/v1/moment-of-inertia— Area & polar moment of inertia
POST/api/v1/beam-section— Beam cross-section properties
POST/api/v1/youngs-modulus— Young's modulus / elasticity
POST/api/v1/hoop-stress— Pressure vessel hoop stress
POST/api/v1/resonance— Natural frequency & resonance
POST/api/v1/damping— Damped vibration response
POST/api/v1/beam-analysis— Beam analysis (FEM)
POST/api/v1/oring— O-ring seal & groove design

Physics

POST/api/v1/suvat— SUVAT kinematics solver

Reference

GET/api/v1/materials— Material properties database
POST/api/v1/unit-conversion— Unit conversion

Structural

POST/api/v1/spring-rate— Helical spring rate

Thermal

POST/api/v1/thermal-expansion— Linear thermal expansion

Try every endpoint live, with request/response schemas and code samples, in the interactive API reference.

CAM Studio G-code API — Access

The CAM Studio compute engine is served behind /cam-api and requires an active CAM Studio subscription (Pro, Team or Enterprise). There is no API key — access is tied to your signed-in session.

See the G-code API reference for endpoint schemas, request examples, and live try-it-out.