{ "openapi": "3.1.1", "info": { "title": "The Compatibility Engine API", "version": "1.0.0", "summary": "Will this charger, cable, version or PC part work together? Rule-based checks with margins.", "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://compatibilityengine.usefulweb.site" } ], "paths": { "/api/v1/calculate": { "post": { "operationId": "calculate", "summary": "Will this charger, cable, version or PC part work together? Rule-based checks with margins.", "description": "Three deterministic checks: (1) USB-C charging – the real maximum power from charger, cable and device per the USB Power Delivery rules; (2) software versions – whether versions satisfy an npm-style semver range (^, ~, x-ranges, hyphen ranges, ||); (3) PC builds – CPU socket, RAM generation, slots and power-supply headroom.\n\nMethodology:\n- Charging: with USB PD on both sides the standard power range allows 5/9/15/20 V at 3 A (≤ 60 W with a standard cable) and 20 V at 5 A (≤ 100 W) with a 5 A e-marked cable; above 100 W (28/36/48 V, ≤ 240 W) needs charger, device AND cable to support PD 3.1 EPR. Without PD on both sides the assumed ceiling is USB-C 5 V / 3 A = 15 W. Expected maximum = minimum of charger, device and that limit.\n- Semver: npm range semantics (^ caret, ~ tilde, x-ranges, hyphen ranges, || alternatives, comparator sets); prereleases only match ranges that mention a prerelease of the same version.\n- PC: sockets must match exactly (case-insensitive); RAM generation must match; modules ≤ slots; recommended PSU = (CPU + GPU + other) × (1 + headroom%).", "tags": [ "high-value" ], "x-mcp-tool": "compatibility_engine", "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/CompatibilityEngineInput" }, "examples": { "example1": { "summary": "140 W laptop on a 100 W charger", "value": { "mode": "charging", "chargerW": 100, "chargerPd": true, "deviceW": 140, "devicePd": true, "deviceEpr": true, "cable": "usb-c-3a" } }, "example2": { "summary": "Node.js engine range", "value": { "mode": "semver", "range": "^18.17.0 || >=20.5.0", "versions": [ "18.16.1", "18.20.4", "20.4.0", "20.11.1", "22.0.0-rc.1", "22.1.0" ] } }, "example3": { "summary": "AM5 gaming PC", "value": { "mode": "pc", "cpuSocket": "AM5", "boardSocket": "AM5", "ramType": "DDR5", "boardRamType": "DDR5", "ramModules": 2, "boardSlots": 4, "cpuW": 120, "gpuW": 285, "otherW": 75, "psuW": 650 } } } } } }, "responses": { "200": { "description": "Calculation result envelope.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/CompatibilityEngineResult" } } } }, "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" } } } } } }, "CompatibilityEngineInput": { "type": "object", "additionalProperties": false, "properties": { "mode": { "title": "What do you want to check?", "type": "string", "enum": [ "charging", "semver", "pc" ], "default": "charging" }, "chargerW": { "title": "Charger maximum output", "description": "Charging mode.", "type": "number", "minimum": 1, "maximum": 1000, "x-unit": "W" }, "chargerPd": { "title": "Charger supports USB Power Delivery (USB PD)", "type": "boolean", "default": true }, "chargerEpr": { "title": "Charger supports PD 3.1 EPR (above 100 W)", "type": "boolean", "default": false }, "deviceW": { "title": "Device maximum charging input", "type": "number", "minimum": 1, "maximum": 1000, "x-unit": "W" }, "devicePd": { "title": "Device charges via USB PD", "type": "boolean", "default": true }, "deviceEpr": { "title": "Device supports PD 3.1 EPR", "type": "boolean", "default": false }, "cable": { "title": "USB-C cable", "type": "string", "enum": [ "usb-c-3a", "usb-c-5a", "usb-c-epr" ], "default": "usb-c-3a" }, "range": { "title": "Required version range", "description": "Semver mode. npm syntax.", "type": "string" }, "versions": { "title": "Installed / candidate versions (one per line)", "type": "array", "items": { "type": "string" }, "maxItems": 50 }, "cpuSocket": { "title": "CPU socket", "description": "PC mode.", "type": "string" }, "boardSocket": { "title": "Motherboard socket", "type": "string" }, "ramType": { "title": "RAM type", "type": "string", "enum": [ "DDR3", "DDR4", "DDR5" ], "default": "DDR5" }, "boardRamType": { "title": "Motherboard RAM type", "type": "string", "enum": [ "DDR3", "DDR4", "DDR5" ], "default": "DDR5" }, "ramModules": { "title": "RAM modules", "type": "integer", "minimum": 1, "maximum": 16 }, "boardSlots": { "title": "Motherboard RAM slots", "type": "integer", "minimum": 1, "maximum": 16 }, "cpuW": { "title": "CPU power (TDP/PPT)", "type": "number", "minimum": 0, "maximum": 1000, "x-unit": "W" }, "gpuW": { "title": "Graphics card power", "type": "number", "minimum": 0, "maximum": 2000, "x-unit": "W" }, "otherW": { "title": "Everything else", "type": "number", "minimum": 0, "maximum": 1000, "default": 75, "x-unit": "W" }, "psuW": { "title": "Power supply rating", "type": "number", "minimum": 100, "maximum": 3000, "x-unit": "W" }, "headroomPercent": { "title": "Desired PSU headroom", "type": "number", "minimum": 0, "maximum": 100, "default": 30, "x-unit": "%" } }, "required": [] }, "CompatibilityEngineResult": { "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", "additionalProperties": false, "required": [ "mode", "compatible", "checks" ], "properties": { "mode": { "type": "string", "enum": [ "charging", "semver", "pc" ] }, "compatible": { "type": "boolean" }, "checks": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "check", "pass", "detail" ], "properties": { "check": { "type": "string" }, "pass": { "type": "boolean" }, "detail": { "type": "string" }, "marginW": { "type": "number" } } } }, "charging": { "type": "object", "additionalProperties": false, "required": [ "expectedMaxW", "bottleneck", "usbPd", "epr", "limits" ], "properties": { "expectedMaxW": { "type": "number" }, "bottleneck": { "type": "array", "items": { "type": "string" } }, "usbPd": { "type": "boolean" }, "epr": { "type": "boolean" }, "limits": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "part", "watts" ], "properties": { "part": { "type": "string" }, "watts": { "type": "number" } } } } } }, "semver": { "type": "object", "additionalProperties": false, "required": [ "range", "results", "highestSatisfying" ], "properties": { "range": { "type": "string" }, "highestSatisfying": { "type": [ "string", "null" ] }, "results": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "version", "satisfies" ], "properties": { "version": { "type": "string" }, "satisfies": { "type": "boolean" } } } } } }, "pc": { "type": "object", "additionalProperties": false, "required": [ "estimatedLoadW", "recommendedPsuW" ], "properties": { "estimatedLoadW": { "type": "number" }, "recommendedPsuW": { "type": "number" } } } } }, "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" } } } } } } } }