{ "openapi": "3.1.1", "info": { "title": "Resistor Color Code API", "version": "1.0.0", "summary": "Decode and encode resistor bands", "description": "Every endpoint performs the same calculation as the human page and returns inputs, result, units, assumptions, sources, warnings and computedAt. MCP endpoint: /mcp." }, "servers": [ { "url": "https://ohmforgeresistorcolorcode.usefulweb.site" } ], "paths": { "/api/v1/calculate": { "post": { "operationId": "calculate", "summary": "Decode and encode resistor bands", "description": "Decode four, five or six color bands or encode an exactly representable resistance, with tolerance and temperature coefficient.\n\nMethodology:\n- Reads two significant digits for four bands and three for five or six bands, then applies the multiplier and tolerance.\n- The optional sixth band is the temperature coefficient in ppm/K. Uses the conventional mappings documented in the linked Vishay chart.\n- Encoding requires an exactly representable value and never silently rounds to a preferred series.\n- The minimum and maximum are nominal resistance multiplied by one minus or plus tolerance; they do not include temperature effects.\n- The nominal value is also checked against the IEC 60063 preferred-number series E6, E12, E24, E48, E96 and E192 (exact match of the significant digits).\n\nThis covers conventional four-, five- and six-band resistor markings. Manufacturers may use different markings, and color appearance or orientation can be ambiguous. Confirm against the component datasheet and measure when uncertain.", "tags": [ "apps" ], "x-mcp-tool": "ohmforge_resistor_color_code", "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/OhmforgeResistorColorCodeInput" }, "examples": { "example1": { "summary": "Decode brown, black, red, gold", "value": { "mode": "decode", "bandCount": "4", "digit1": "brown", "digit2": "black", "multiplier": "red", "tolerance": "gold" } }, "example2": { "summary": "Encode a 4.7 kΩ precision resistor", "value": { "mode": "encode", "bandCount": "5", "ohms": 4700, "tolerance": "brown" } }, "example3": { "summary": "Six bands with temperature coefficient", "value": { "mode": "decode", "bandCount": "6", "digit1": "brown", "digit2": "black", "digit3": "black", "multiplier": "red", "tolerance": "brown", "temperature": "red" } } } } } }, "responses": { "200": { "description": "Calculation result envelope.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/OhmforgeResistorColorCodeResult" } } } }, "400": { "description": "Malformed JSON body.", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } }, "422": { "description": "Invalid input (see errors[]).", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } }, "429": { "description": "Rate limit exceeded (see Retry-After).", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } } } } }, "/api/v1/tool": { "get": { "operationId": "getToolDefinition", "summary": "Inputs, output schema and examples for this tool", "responses": { "200": { "description": "Tool definition.", "content": { "application/json": { "schema": { "type": "object" } } } } } } } }, "components": { "schemas": { "Problem": { "type": "object", "description": "RFC 9457 problem details. 422 responses include per-field `errors`.", "required": [ "type", "title", "status", "detail" ], "properties": { "type": { "type": "string" }, "title": { "type": "string" }, "status": { "type": "integer" }, "detail": { "type": "string" }, "code": { "type": "string" }, "errors": { "type": "array", "items": { "type": "object", "required": [ "field", "message" ], "properties": { "field": { "type": "string" }, "message": { "type": "string" } } } } } }, "OhmforgeResistorColorCodeInput": { "type": "object", "additionalProperties": false, "properties": { "mode": { "title": "Calculate", "type": "string", "enum": [ "decode", "encode" ], "default": "decode" }, "bandCount": { "title": "Number of bands", "type": "string", "enum": [ "4", "5", "6" ], "default": "4" }, "digit1": { "title": "First significant band (decode)", "type": "string", "enum": [ "brown", "red", "orange", "yellow", "green", "blue", "violet", "gray", "white" ], "default": "brown" }, "digit2": { "title": "Second significant band (decode)", "type": "string", "enum": [ "black", "brown", "red", "orange", "yellow", "green", "blue", "violet", "gray", "white" ], "default": "black" }, "digit3": { "title": "Third significant band (5 or 6 bands, decode)", "type": "string", "enum": [ "black", "brown", "red", "orange", "yellow", "green", "blue", "violet", "gray", "white" ], "default": "black" }, "multiplier": { "title": "Multiplier band (decode)", "type": "string", "enum": [ "silver", "gold", "black", "brown", "red", "orange", "yellow", "green", "blue", "violet", "gray", "white" ], "default": "red" }, "tolerance": { "title": "Tolerance band", "type": "string", "enum": [ "silver", "gold", "brown", "red", "green", "blue", "violet", "gray" ], "default": "gold" }, "temperature": { "title": "Temperature coefficient band (6 bands)", "type": "string", "enum": [ "brown", "red", "yellow", "orange", "blue", "violet" ], "default": "brown" }, "ohms": { "title": "Resistance in ohms (encode)", "type": "number", "minimum": 0.1, "maximum": 999000000000, "default": 1000, "x-unit": "Ω" } }, "required": [] }, "OhmforgeResistorColorCodeResult": { "type": "object", "additionalProperties": false, "required": [ "schemaVersion", "tool", "computedAt", "inputs", "summary", "result", "units", "assumptions", "sources", "warnings", "presentation", "links" ], "properties": { "schemaVersion": { "type": "string", "const": "1.0" }, "tool": { "type": "object", "additionalProperties": false, "required": [ "id", "name", "version" ], "properties": { "id": { "type": "string" }, "name": { "type": "string" }, "version": { "type": "string" } } }, "computedAt": { "type": "string", "format": "date-time" }, "inputs": { "type": "object", "description": "Normalised inputs actually used, including applied defaults." }, "summary": { "type": "string" }, "result": { "type": "object", "required": [ "bands", "ohms", "tolerancePercent", "minimumOhms", "maximumOhms", "temperatureCoefficientPpmPerK", "preferredSeries" ], "properties": { "bands": { "type": "array", "items": { "type": "string" } }, "ohms": { "type": "number" }, "tolerancePercent": { "type": "number" }, "minimumOhms": { "type": "number" }, "maximumOhms": { "type": "number" }, "temperatureCoefficientPpmPerK": { "type": [ "number", "null" ] }, "preferredSeries": { "type": "array", "items": { "type": "string", "enum": [ "E6", "E12", "E24", "E48", "E96", "E192" ] } } }, "additionalProperties": false }, "units": { "type": "object", "additionalProperties": { "type": "string" } }, "assumptions": { "type": "array", "items": { "type": "string" } }, "sources": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "title" ], "properties": { "title": { "type": "string" }, "url": { "type": "string" }, "publisher": { "type": "string" }, "retrievedAt": { "type": "string" }, "note": { "type": "string" } } } }, "warnings": { "type": "array", "items": { "type": "string" } }, "presentation": { "type": "array", "items": { "type": "object" }, "description": "Display blocks used by the human page (same data)." }, "links": { "type": "object", "additionalProperties": false, "required": [ "human", "api", "openapi", "methodology" ], "properties": { "human": { "type": "string", "format": "uri" }, "api": { "type": "string", "format": "uri" }, "openapi": { "type": "string", "format": "uri" }, "methodology": { "type": "string", "format": "uri" } } } } } } } }