{ "openapi": "3.1.1", "info": { "title": "OpenAPI Diff Explorer API", "version": "1.0.0", "summary": "Compare two versions of an OpenAPI spec and see exactly which changes break clients.", "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://openapidiffexplorer.usefulweb.site" } ], "paths": { "/api/v1/calculate": { "post": { "operationId": "calculate", "summary": "Compare two versions of an OpenAPI spec and see exactly which changes break clients.", "description": "Paste or link two OpenAPI 3.x (or Swagger 2) documents in JSON or YAML. Every operation, parameter, request body, response and schema property is compared (with $ref resolution), and each change is classified as breaking, potentially breaking or non-breaking, with the direction-aware rules API teams use (e.g. a new required request field breaks clients; a new response field does not; a new response enum value might).\n\nMethodology:\n- Operations are matched by method + path; paths that differ only in parameter names ({id} vs {orderId}) are treated as the same operation.\n- Request side (parameters, bodies): removing accepted values, adding required inputs, tightening limits or changing types is breaking.\n- Response side: removing properties or success responses, or making a guaranteed field optional, is breaking; new enum values, new nullability and new success codes are potentially breaking; additions are non-breaking.\n- Local $refs are resolved (cycles detected). Removed operations and changed security requirements are breaking.\n- Semver advice: any breaking change → major; additions only → minor; otherwise patch.", "tags": [ "devcloud" ], "x-mcp-tool": "openapi_diff_explorer", "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/OpenapiDiffExplorerInput" }, "examples": { "example1": { "summary": "Shop API v1 → v2", "value": { "oldSpec": "openapi: 3.0.3\ninfo:\n title: Shop API\n version: 1.0.0\npaths:\n /orders:\n get:\n operationId: listOrders\n parameters:\n - name: limit\n in: query\n schema: {type: integer, maximum: 100}\n responses:\n '200':\n description: ok\n content:\n application/json:\n schema:\n type: array\n items: {$ref: '#/components/schemas/Order'}\n post:\n operationId: createOrder\n requestBody:\n content:\n application/json:\n schema:\n type: object\n properties:\n sku: {type: string}\n note: {type: string}\n required: [sku]\n responses:\n '201': {description: created}\n /orders/{id}:\n delete:\n operationId: deleteOrder\n parameters:\n - {name: id, in: path, required: true, schema: {type: string}}\n responses:\n '204': {description: deleted}\ncomponents:\n schemas:\n Order:\n type: object\n required: [id, status]\n properties:\n id: {type: string}\n status: {type: string, enum: [open, shipped]}\n total: {type: number}\n", "newSpec": "openapi: 3.0.3\ninfo:\n title: Shop API\n version: 1.0.0\npaths:\n /orders:\n get:\n operationId: listOrders\n parameters:\n - name: limit\n in: query\n schema: {type: integer, maximum: 50}\n responses:\n '200':\n description: ok\n content:\n application/json:\n schema:\n type: array\n items: {$ref: '#/components/schemas/Order'}\n post:\n operationId: createOrder\n requestBody:\n content:\n application/json:\n schema:\n type: object\n properties:\n sku: {type: string}\n quantity: {type: integer}\n required: [sku, quantity]\n responses:\n '201': {description: created}\ncomponents:\n schemas:\n Order:\n type: object\n required: [id, status]\n properties:\n id: {type: string}\n status: {type: string, enum: [open, shipped, cancelled]}\n" } } } } } }, "responses": { "200": { "description": "Calculation result envelope.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/OpenapiDiffExplorerResult" } } } }, "400": { "description": "Malformed JSON body.", "content": { "application/problem+json": { "schema": { "$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" } } } } } }, "OpenapiDiffExplorerInput": { "type": "object", "additionalProperties": false, "properties": { "oldSpec": { "title": "Old spec (JSON or YAML)", "type": "string", "maxLength": 4000000 }, "newSpec": { "title": "New spec (JSON or YAML)", "type": "string", "maxLength": 4000000 }, "oldUrl": { "title": "Or: URL of the old spec", "type": "string", "format": "uri" }, "newUrl": { "title": "Or: URL of the new spec", "type": "string", "format": "uri" } }, "required": [] }, "OpenapiDiffExplorerResult": { "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": [ "old", "new", "counts", "changes", "semverAdvice" ], "properties": { "old": { "type": "object", "additionalProperties": false, "required": [ "title", "version", "operations" ], "properties": { "title": { "type": [ "string", "null" ] }, "version": { "type": [ "string", "null" ] }, "operations": { "type": "integer" } } }, "new": { "type": "object", "additionalProperties": false, "required": [ "title", "version", "operations" ], "properties": { "title": { "type": [ "string", "null" ] }, "version": { "type": [ "string", "null" ] }, "operations": { "type": "integer" } } }, "counts": { "type": "object", "additionalProperties": false, "required": [ "breaking", "potentiallyBreaking", "nonBreaking" ], "properties": { "breaking": { "type": "integer" }, "potentiallyBreaking": { "type": "integer" }, "nonBreaking": { "type": "integer" } } }, "semverAdvice": { "type": "string", "enum": [ "major", "minor", "patch" ] }, "changes": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "severity", "location", "change", "detail" ], "properties": { "severity": { "type": "string", "enum": [ "breaking", "potentially-breaking", "non-breaking" ] }, "location": { "type": "string" }, "change": { "type": "string" }, "detail": { "type": "string" } } } } } }, "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" } } } } } } } }