> ## Documentation Index > Fetch the complete documentation index at: https://docs.lerian.studio/llms.txt > Use this file to discover all available pages before exploring further. # Preview amortisation schedule > Computes a deterministic declining-balance schedule for the supplied loan parameters without persisting any data. ## OpenAPI ````yaml en/openapi/v3-current/lender.yaml post /api/v1/loan-applications/preview-schedule openapi: 3.1.0 info: contact: email: contact@lerian.studio name: Lerian Studio url: https://lerian.studio description: Code-first OpenAPI 3.1 surface for the Lender service. license: name: Lerian Studio General License title: Lender API version: 1.0.0 servers: - url: https://lender.sandbox.lerian.net security: - BearerAuth: [] tags: - description: >- Ledger accounting operations: journal entries and accrual postings for loan accounts. name: Accounting - description: >- Loan application intake and lifecycle: submission, decisioning, and status. name: LoanApplications - description: >- Loan product catalog: definition, versioning, and activation of lending products. name: LoanProducts - description: >- Loan account servicing operations: balances, schedules, and account-level actions. name: Loan Accounts - description: >- Servicing read operations: repayment schedules and servicing state for loan accounts. name: Servicings - description: >- Portfolio dashboard read operations: aggregated portfolio and performance views. name: Dashboard - description: >- Jurisdiction registry: supported jurisdiction profiles and their capabilities. name: Jurisdictions - description: >- Jurisdiction-specific loan application operations (Brazil origination surface). name: Loan Applications - description: >- Tax computation operations for jurisdiction-specific lending (e.g. Brazil IOF). name: Tax - description: >- Brazil consignado privado operations: contract origination (contratação ativa) and lifecycle. name: Consignado paths: /api/v1/loan-applications/preview-schedule: post: tags: - LoanApplications summary: Preview amortisation schedule description: >- Computes a deterministic declining-balance schedule for the supplied loan parameters without persisting any data. operationId: previewLoanSchedule requestBody: content: application/json: schema: $ref: '#/components/schemas/SchedulePreviewHumaRequest' required: true responses: '200': content: application/json: schema: $ref: '#/components/schemas/SchedulePreviewHumaBody' description: OK default: content: application/problem+json: schema: $ref: '#/components/schemas/Detail' description: Error components: schemas: SchedulePreviewHumaRequest: additionalProperties: false properties: annualInterestRate: description: Annual interest rate as a decimal string (e.g. "0.12000000"). examples: - '0.12000000' type: string dayCountConvention: description: Day count convention identifier. examples: - ACT/365 type: string gracePeriodDays: description: Grace period in days. examples: - 30 format: int64 maximum: 365 minimum: 0 type: integer jurisdictionCode: description: ISO-2 jurisdiction code. examples: - BR maxLength: 2 minLength: 2 type: string principalAmount: description: Principal amount as a decimal string (e.g. "50000.00"). examples: - '50000.00' type: string startDate: description: Schedule start date (RFC3339 or YYYY-MM-DD). examples: - '2026-06-14T00:00:00Z' type: string termMonths: description: Number of months. examples: - 24 format: int64 maximum: 600 minimum: 1 type: integer required: - principalAmount - annualInterestRate - termMonths - dayCountConvention - jurisdictionCode - startDate type: object SchedulePreviewHumaBody: additionalProperties: false properties: calendarReference: description: Identifier of the business calendar used to resolve due dates. type: string dayCountConvention: description: Day count convention applied to interest accrual. examples: - ACT/365 type: string effectiveCostPreview: $ref: '#/components/schemas/SchedulePreviewHumaEffectiveCost' description: >- Effective-cost breakdown; present only when the jurisdiction profile computes one. installments: description: Ordered amortisation schedule, one entry per installment. items: $ref: '#/components/schemas/SchedulePreviewHumaInstallmentLine' type: - array - 'null' jurisdictionCode: description: ISO-2 jurisdiction code resolved for this preview. examples: - BR type: string jurisdictionExtensions: $ref: '#/components/schemas/SchedulePreviewHumaJurisdictionExtensions' description: >- Per-jurisdiction overlay payload; present only when the profile emits one. profileVersion: description: Jurisdiction profile version used to compute the schedule. examples: - 1.0.0 type: string totalInterest: description: >- Sum of interest across all installments as a decimal string, minor-unit precision scale 2 (e.g. "4321.00"). examples: - '4321.00' type: string totalPrincipal: description: >- Sum of principal across all installments as a decimal string, minor-unit precision scale 2 (e.g. "50000.00"). examples: - '50000.00' type: string required: - installments - totalInterest - totalPrincipal - jurisdictionCode - profileVersion - dayCountConvention - calendarReference type: object Detail: additionalProperties: false properties: code: description: >- Stable, machine-readable domain error code scoped to the emitting service (format: -NNNN). examples: - ERR-0001 type: string detail: description: >- A human-readable explanation specific to this occurrence of the problem. examples: - Property foo is required but is missing. type: string errors: description: Optional list of individual error details items: $ref: '#/components/schemas/ErrorDetail' type: - array - 'null' instance: description: >- A URI reference that identifies the specific occurrence of the problem. examples: - https://example.com/error-log/abc123 format: uri type: string status: description: HTTP status code examples: - 400 format: int64 type: integer title: description: >- A short, human-readable summary of the problem type. This value should not change between occurrences of the error. examples: - Bad Request type: string type: default: about:blank description: A URI reference to human-readable documentation for the error. examples: - https://example.com/errors/example format: uri type: string type: object SchedulePreviewHumaEffectiveCost: additionalProperties: false properties: effectiveCostAnnualPct: description: >- Effective annual cost as a decimal-string percentage, scale 8 (e.g. "12.00000000"). examples: - '12.00000000' type: string effectiveCostMonthlyPct: description: >- Effective monthly cost as a decimal-string percentage, scale 8 (e.g. "0.94888100"). examples: - '0.94888100' type: string memoryOfCalculation: additionalProperties: {} description: >- Opaque step-by-step record of the effective-cost calculation (audit trail). type: object methodId: description: >- Identifier of the effective-cost calculation method applied by the jurisdiction profile. type: string rateTableSnapshot: additionalProperties: {} description: Opaque snapshot of the rate table inputs used in the calculation. type: object required: - methodId - effectiveCostAnnualPct - effectiveCostMonthlyPct - rateTableSnapshot - memoryOfCalculation type: object SchedulePreviewHumaInstallmentLine: additionalProperties: false properties: dueDate: description: Installment due date (date-only, YYYY-MM-DD). examples: - '2026-06-14' type: string interestAmount: description: >- Interest portion of the installment as a decimal string, minor-unit precision scale 2 (e.g. "234.56"). examples: - '234.56' type: string number: description: 1-based installment sequence number. examples: - 1 format: int64 type: integer principalAmount: description: >- Principal portion of the installment as a decimal string, minor-unit precision scale 2 (e.g. "1000.00"). examples: - '1000.00' type: string remainingBalance: description: >- Outstanding principal balance after this installment as a decimal string, minor-unit precision scale 2 (e.g. "49000.00"). examples: - '49000.00' type: string totalAmount: description: >- Total installment amount (principal + interest) as a decimal string, minor-unit precision scale 2 (e.g. "1234.56"). examples: - '1234.56' type: string required: - number - dueDate - totalAmount - principalAmount - interestAmount - remainingBalance type: object SchedulePreviewHumaJurisdictionExtensions: additionalProperties: false properties: body: additionalProperties: {} description: >- Opaque per-jurisdiction overlay payload decoded from the use-case result. type: object overlayKey: description: >- Identifier of the jurisdiction overlay that produced this extension payload. type: string required: - overlayKey - body type: object ErrorDetail: additionalProperties: false properties: location: description: >- Where the error occurred, e.g. 'body.items[3].tags' or 'path.thing-id' type: string message: description: Error message text type: string value: description: The value at the given location type: object securitySchemes: BearerAuth: bearerFormat: JWT description: JWT bearer token issued by the identity provider. scheme: bearer type: http ````