{ "openapi": "3.1.0", "info": { "title": "Lendtrain Agent API", "version": "2.1.0", "description": "Structured refinance estimates and conversational guidance. Atlantic Home Mortgage, LLC dba Lendtrain. NMLS #1844873. Equal Housing Opportunity. No application submission, credit pull, rate lock, or messaging." }, "servers": [ { "url": "https://www.lendtrain.com" } ], "paths": { "/api/agents/quote": { "post": { "operationId": "quote", "summary": "Price a known refinance scenario", "security": [], "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/QuoteRequest" } } } }, "responses": { "200": { "description": "Completed response. Inspect status and disclosures before presenting an estimate.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/QuoteResponse" } } } }, "400": { "description": "JSON error. Correct invalid inputs or retry temporary errors with bounded backoff.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } }, "403": { "description": "JSON error. Correct invalid inputs or retry temporary errors with bounded backoff.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } }, "413": { "description": "JSON error. Correct invalid inputs or retry temporary errors with bounded backoff.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } }, "429": { "description": "JSON error. Correct invalid inputs or retry temporary errors with bounded backoff.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } }, "502": { "description": "JSON error. Correct invalid inputs or retry temporary errors with bounded backoff.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } }, "503": { "description": "JSON error. Correct invalid inputs or retry temporary errors with bounded backoff.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } }, "504": { "description": "JSON error. Correct invalid inputs or retry temporary errors with bounded backoff.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } } }, "description": "FHA is never returned. VA requires explicit borrower eligibility and fee status. VA rate-and-term from a non-VA or unknown loan requires officer review. 15-second upstream timeout. 10 requests/min/IP shared with site pricing. Savings require complete current-loan data and are omitted for cash-out. Costs and savings refer to parRate. Other rate choices change costs. Cash-out excludes financed closing costs. Estimates only, not underwriting approval." } }, "/api/chat": { "post": { "operationId": "chat", "summary": "Ask the refinance advisor", "security": [], "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/ChatRequest" } } } }, "responses": { "200": { "description": "Completed response. Inspect status and disclosures before presenting an estimate.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/ChatResponse" } }, "text/event-stream": { "schema": { "$ref": "#/components/schemas/ChatStreamEvent" }, "example": "data: {\"text\":\"Final answer\"}\n\ndata: [DONE]\n\n" } } }, "400": { "description": "JSON error. Correct invalid inputs or retry temporary errors with bounded backoff.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } }, "403": { "description": "JSON error. Correct invalid inputs or retry temporary errors with bounded backoff.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } }, "413": { "description": "JSON error. Correct invalid inputs or retry temporary errors with bounded backoff.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } }, "429": { "description": "JSON error. Correct invalid inputs or retry temporary errors with bounded backoff.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } }, "502": { "description": "JSON error. Correct invalid inputs or retry temporary errors with bounded backoff.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } }, "503": { "description": "JSON error. Correct invalid inputs or retry temporary errors with bounded backoff.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } }, "504": { "description": "JSON error. Correct invalid inputs or retry temporary errors with bounded backoff.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/Error" } } } } }, "description": "Defaults to SSE. Set stream:false for JSON with structured quotes. 90-second deadline. 20 requests/min/IP. Pricing calls share the 10/min/IP pricing limit. vaEligibilityConfirmed:true is required for VA. No application submission, rate lock, credit pull, or email actions." } } }, "components": { "schemas": { "QuoteRequest": { "type": "object", "properties": { "state": { "type": "string", "enum": [ "AL", "FL", "GA", "KY", "NC", "OR", "SC", "TN", "TX", "UT" ] }, "loanBalance": { "type": "number", "exclusiveMinimum": 0, "maximum": 10000000 }, "propertyValue": { "type": "number", "exclusiveMinimum": 0, "maximum": 50000000 }, "creditScore": { "type": "integer", "minimum": 300, "maximum": 850 }, "occupancy": { "type": "string", "enum": [ "primary", "secondHome", "investment" ] }, "propertyType": { "type": "string", "enum": [ "singleFamily", "condo", "townhouse", "multiUnit", "manufactured" ] }, "units": { "type": "integer", "minimum": 1, "maximum": 4 }, "loanPurpose": { "type": "string", "enum": [ "rateTermRefi", "cashOutRefi" ] }, "cashOutAmount": { "type": "number", "minimum": 0, "maximum": 10000000 }, "loanTerm": { "anyOf": [ { "type": "number", "const": 10 }, { "type": "number", "const": 15 }, { "type": "number", "const": 20 }, { "type": "number", "const": 25 }, { "type": "number", "const": 30 } ] }, "currentLoanType": { "type": "string", "enum": [ "conventional", "fha", "va", "unknown" ] }, "isVeteran": { "type": "boolean", "description": "True only when the borrower explicitly confirms VA eligibility. Otherwise false." }, "currentRate": { "anyOf": [ { "type": "number", "minimum": 0, "maximum": 30 }, { "type": "null" } ] }, "currentMonthlyPayment": { "anyOf": [ { "type": "number", "exclusiveMinimum": 0, "maximum": 100000 }, { "type": "null" } ], "description": "Principal and interest only, excluding escrow and mortgage insurance." }, "remainingTermMonths": { "anyOf": [ { "type": "integer", "minimum": 1, "maximum": 480 }, { "type": "null" } ] }, "currentMonthlyMip": { "anyOf": [ { "type": "number", "minimum": 0, "maximum": 10000 }, { "type": "null" } ] }, "vaFundingFeeType": { "anyOf": [ { "type": "string", "enum": [ "firstTime", "subsequent", "exempt" ] }, { "type": "null" } ] } }, "required": [ "state", "loanBalance", "propertyValue", "creditScore", "occupancy", "propertyType", "units", "loanPurpose", "cashOutAmount", "loanTerm", "currentLoanType", "isVeteran", "currentRate", "currentMonthlyPayment", "remainingTermMonths", "currentMonthlyMip", "vaFundingFeeType" ], "additionalProperties": false }, "ChatRequest": { "type": "object", "properties": { "messages": { "minItems": 1, "maxItems": 50, "type": "array", "items": { "type": "object", "properties": { "role": { "type": "string", "enum": [ "user", "assistant" ] }, "content": { "type": "string", "minLength": 1, "maxLength": 10000 } }, "required": [ "role", "content" ], "additionalProperties": false } }, "stream": { "type": "boolean" }, "vaEligibilityConfirmed": { "type": "boolean" } }, "required": [ "messages" ], "additionalProperties": false }, "RateOption": { "type": "object", "properties": { "rate": { "type": "number", "exclusiveMinimum": 0 }, "apr": { "type": "number", "exclusiveMinimum": 0 }, "points": { "type": "number" }, "dollarAmount": { "type": "number" }, "monthlyPI": { "type": "number", "minimum": 0 }, "monthlyPayment": { "type": "number", "minimum": 0 }, "totalMonthlyPayment": { "type": "number", "minimum": 0 }, "monthlyMI": { "type": "number", "minimum": 0 }, "isPar": { "type": "boolean" }, "label": { "type": "string" }, "borrowerPaidPoints": { "type": "number", "minimum": 0, "description": "Borrower-paid points in dollars." }, "lenderCredit": { "type": "number", "minimum": 0, "description": "Credit toward closing costs in dollars, not cash proceeds." } }, "required": [ "rate", "apr", "points", "dollarAmount", "label", "borrowerPaidPoints", "lenderCredit" ], "additionalProperties": false }, "Product": { "type": "object", "properties": { "eligible": { "type": "boolean", "const": true }, "parRate": { "type": "number", "exclusiveMinimum": 0 }, "apr": { "type": "number", "exclusiveMinimum": 0 }, "monthlyPI": { "type": "number", "minimum": 0 }, "totalMonthlyPayment": { "type": "number", "minimum": 0 }, "rateOptions": { "type": "array", "items": { "$ref": "#/components/schemas/RateOption" } }, "fullRateChain": { "type": "array", "items": { "$ref": "#/components/schemas/RateOption" } }, "ltv": { "type": "number", "minimum": 0 }, "closingCosts": { "type": "object", "properties": { "total": { "type": "number", "minimum": 0 }, "lenderFees": { "type": "object", "properties": { "underwriting": { "type": "number", "minimum": 0 }, "discountPoints": { "type": "number" } }, "required": [ "underwriting", "discountPoints" ], "additionalProperties": false }, "thirdPartyFees": { "type": "object", "properties": { "creditReport": { "type": "number", "minimum": 0 }, "appraisal": { "type": "number", "minimum": 0 }, "floodCert": { "type": "number", "minimum": 0 }, "taxService": { "type": "number", "minimum": 0 }, "subtotal": { "type": "number", "minimum": 0 } }, "required": [ "creditReport", "appraisal", "floodCert", "taxService", "subtotal" ], "additionalProperties": false }, "titleSettlement": { "type": "object", "properties": { "settlementFee": { "type": "number", "minimum": 0 }, "titleInsurance": { "type": "number", "minimum": 0 }, "cpl": { "type": "number", "minimum": 0 }, "subtotal": { "type": "number", "minimum": 0 } }, "required": [ "settlementFee", "titleInsurance", "cpl", "subtotal" ], "additionalProperties": false }, "governmentRecording": { "type": "object", "properties": { "recordingFees": { "type": "number", "minimum": 0 }, "stateTaxes": { "type": "number", "minimum": 0 }, "subtotal": { "type": "number", "minimum": 0 } }, "required": [ "recordingFees", "stateTaxes" ], "additionalProperties": false }, "productSpecific": { "type": "object", "properties": { "vaFundingFee": { "type": "number", "minimum": 0 } }, "additionalProperties": false } }, "required": [ "total", "lenderFees", "thirdPartyFees", "titleSettlement", "governmentRecording" ], "additionalProperties": false }, "monthlySavings": { "type": "number" }, "annualSavings": { "type": "number" }, "breakevenMonths": { "anyOf": [ { "type": "number" }, { "type": "null" } ] }, "totalInterestSaved": { "type": "number" }, "conventionalMI": { "type": "object", "properties": { "annualRate": { "type": "number", "minimum": 0 }, "monthlyAmount": { "type": "number", "minimum": 0 }, "coveragePercent": { "type": "number", "minimum": 0 } }, "required": [ "annualRate", "monthlyAmount", "coveragePercent" ], "additionalProperties": false }, "financedFees": { "type": "object", "properties": { "vaFundingFee": { "type": "number", "minimum": 0 }, "fundingFeePercent": { "type": "number", "minimum": 0 }, "totalFinanced": { "type": "number", "minimum": 0 }, "totalLoanAmount": { "type": "number", "minimum": 0 } }, "required": [ "totalFinanced", "totalLoanAmount" ], "additionalProperties": false } }, "required": [ "eligible", "parRate", "apr", "monthlyPI", "totalMonthlyPayment", "rateOptions", "ltv", "closingCosts" ], "additionalProperties": false }, "IneligibleProduct": { "type": "object", "required": [ "eligible", "reason" ], "properties": { "eligible": { "const": false }, "reason": { "type": "string" } } }, "QuoteResponse": { "type": "object", "required": [ "status", "products", "recommendedProduct", "effectiveDate", "calculatedAt", "savingsAvailable", "assumptions", "notices", "disclosure", "nextStep" ], "properties": { "status": { "type": "string", "enum": [ "quoted", "no_eligible_products" ] }, "products": { "type": "object", "additionalProperties": false, "properties": { "conventional": { "oneOf": [ { "$ref": "#/components/schemas/Product" }, { "$ref": "#/components/schemas/IneligibleProduct" } ] }, "va": { "oneOf": [ { "$ref": "#/components/schemas/Product" }, { "$ref": "#/components/schemas/IneligibleProduct" } ] } } }, "recommendedProduct": { "type": [ "string", "null" ], "enum": [ "conventional", "va", null ] }, "effectiveDate": { "type": "string", "description": "Rate sheet effective date as supplied by the pricing service." }, "effectiveTime": { "type": "string" }, "calculatedAt": { "type": "string" }, "savingsAvailable": { "type": "boolean" }, "assumptions": { "type": "object", "properties": { "lockPeriodDays": { "const": 30 }, "otherClosingCostsFinanced": { "const": false }, "requestedCashOut": { "type": "number" }, "baseLoanAmount": { "type": "number" } } }, "notices": { "type": "array", "items": { "type": "string" } }, "disclosure": { "type": "string" }, "nextStep": { "type": "object", "properties": { "action": { "const": "borrower_application" }, "url": { "type": "string", "format": "uri" }, "requiresBorrowerAction": { "const": true }, "instructions": { "type": "string" } } } } }, "ChatResponse": { "type": "object", "required": [ "role", "content", "quotes" ], "properties": { "role": { "const": "assistant" }, "content": { "type": "string" }, "quotes": { "type": "array", "items": { "$ref": "#/components/schemas/QuoteResponse" } } } }, "Error": { "type": "object", "required": [ "error", "code" ], "properties": { "error": { "type": "string" }, "code": { "type": "string" } } }, "ChatStreamEvent": { "oneOf": [ { "type": "object", "required": [ "text" ], "properties": { "text": { "type": "string" } } }, { "$ref": "#/components/schemas/Error" } ], "description": "SSE data payload. Comments start with a colon. Read until the literal data: [DONE]. An error event means failure, including on HTTP 200." } } } }