Resistora

Resistora API & MCP

Run resistor combination search, E-series matching, voltage divider design, and circuit calculations from your own code via a clean REST API — or connect them to your AI assistant through the built-in MCP server.

PRO Plan Required
API Documentation
Interactive API documentation with request/response examples

Both link to the same OpenAPI spec — choose whichever UI you prefer.

Getting Started
Three steps to start using the API
  1. 1

    Create an account

    Register for a Resistora account and upgrade to the PRO plan.

  2. 2

    Generate an API token

    Go to your Account page and generate an API token.

  3. 3

    Make API requests

    Include your token in the X-API-Key header and follow the API documentation for endpoint details.

Available Features

Resistor Combination

Find optimal resistor combinations from your available resistors (2–4 resistors)

Resistor Combination (Pro)

Genetic-algorithm solver over any custom resistor values, with top-10 results (2–4 resistors, PRO only)

E-Series Finder

Find resistor combinations from standard E-series (E6–E192)

Voltage Divider

Design voltage divider circuits with optimal resistor pairs

Divider Builder

Calculate output voltage for a given voltage divider configuration

Circuit Calculator

Calculate total resistance for custom circuit schemas (16 series/parallel schemas)

Circuit Builder

Calculate resistance for a single circuit schema with given resistor values

Rate Limits

PRO Plan Limits
Per-feature rate limits for API access
FeatureRPMDailyMonthly
Resistor Combination305005,000
Resistor Combination (Pro)101001,000
E-Series Finder305005,000
E-Series Finder (Pro)305005,000
Voltage Divider101001,000
Voltage Divider (Pro)101001,000
Divider Builder1001,000Unlimited
Circuit Calculator1001,000Unlimited
Circuit Builder1001,000Unlimited