> ## Documentation Index > Fetch the complete documentation index at: https://docs.tilt.now/llms.txt > Use this file to discover all available pages before exploring further. # Create Account Backtest > Start a new backtest job for a client ## OpenAPI ````yaml POST /api/v1/custom/org/{organization_uuid}/clients/{client_uuid}/accounts/{account_uuid}/backtests/ openapi: 3.0.3 info: title: TILT version: 0.0.1 servers: [] security: [] paths: /api/v1/custom/org/{organization_uuid}/clients/{client_uuid}/accounts/{account_uuid}/backtests/: post: tags: - api description: Start a new backtest job for a client operationId: api_v1_custom_org_clients_accounts_backtests_create parameters: - in: path name: account_uuid schema: type: string format: uuid required: true - in: path name: client_uuid schema: type: string format: uuid required: true - in: path name: organization_uuid schema: type: string format: uuid required: true requestBody: content: application/json: schema: $ref: '#/components/schemas/StartBacktestRequest' application/x-www-form-urlencoded: schema: $ref: '#/components/schemas/StartBacktestRequest' multipart/form-data: schema: $ref: '#/components/schemas/StartBacktestRequest' responses: '202': content: application/json: schema: $ref: '#/components/schemas/CustomizationBacktestJob' description: '' security: - ProAPIToken: [] components: schemas: StartBacktestRequest: type: object properties: start_date: type: string format: date end_date: type: string format: date rebalance_period: allOf: - $ref: '#/components/schemas/StartBacktestRequestRebalancePeriodEnum' default: MONTHLY tax_gamma: type: number format: double maximum: 100 minimum: 0 tax_loss_threshold_bps: type: number format: double maximum: 5000 minimum: 0 starting_nav: type: number format: double maximum: 1000000000 minimum: 100 ls_tlh_factor: $ref: '#/components/schemas/LsTlhFactorEnum' CustomizationBacktestJob: type: object properties: id: type: string format: uuid readOnly: true status: allOf: - $ref: '#/components/schemas/ScenarioAnalysisJobStatusEnum' readOnly: true params: allOf: - $ref: '#/components/schemas/StartBacktestRequest' readOnly: true nullable: true resolved_params: allOf: - $ref: '#/components/schemas/BacktestResolvedParams' nullable: true readOnly: true progress: allOf: - $ref: '#/components/schemas/BacktestProgress' nullable: true readOnly: true result: type: object additionalProperties: $ref: '#/components/schemas/BacktestCaseResult' description: Dictionary mapping case names to case results readOnly: true error_message: type: string nullable: true readOnly: true created_at: type: string format: date-time readOnly: true started_at: type: string format: date-time readOnly: true nullable: true finished_at: type: string format: date-time readOnly: true nullable: true required: - created_at - error_message - finished_at - id - params - progress - resolved_params - result - started_at - status StartBacktestRequestRebalancePeriodEnum: enum: - MONTHLY type: string description: '* `MONTHLY` - MONTHLY' LsTlhFactorEnum: enum: - quality - value - growth type: string description: |- * `quality` - quality * `value` - value * `growth` - growth ScenarioAnalysisJobStatusEnum: enum: - PENDING - RUNNING - SUCCESS - FAILURE type: string description: |- * `PENDING` - PENDING * `RUNNING` - RUNNING * `SUCCESS` - SUCCESS * `FAILURE` - FAILURE BacktestResolvedParams: type: object properties: start_date: type: string format: date end_date: type: string format: date rebalance_period: $ref: '#/components/schemas/BacktestResolvedParamsRebalancePeriodEnum' starting_nav: type: number format: double tax_gamma: type: number format: double nullable: true tax_loss_threshold_bps: type: number format: double nullable: true required: - end_date - rebalance_period - start_date - starting_nav - tax_gamma - tax_loss_threshold_bps BacktestProgress: type: object properties: planned_periods: type: integer completed_periods: type: integer last_completed_period: type: string format: date nullable: true last_progress_at: type: string format: date-time nullable: true required: - completed_periods - last_completed_period - last_progress_at - planned_periods BacktestCaseResult: type: object description: Serializer for a single case's backtest results. properties: run_evidence: type: object additionalProperties: {} description: >- Recorded run: schema (1), build (release, engine_version), initialization (kind, starting_nav), window (requested_start, requested_end, first_solve_date, last_solve_date, last_nav_date), periods (date, risk_model_snapshot, effective_tax_gamma, effective_tax_loss_threshold_bps, tax_budget_selected_gamma), tax_gamma (requested, differing_dates, not_captured_dates). Uncaptured values are null. complete: type: boolean backtest_dispositions: type: array items: type: object additionalProperties: {} input_provenance: type: array items: type: object additionalProperties: {} recovery_receipts: type: array items: type: object additionalProperties: {} summaries: type: object additionalProperties: type: object additionalProperties: type: number format: double nullable: true description: Dictionary mapping quantity names to date-to-value mappings tax_summaries: type: object additionalProperties: type: object additionalProperties: type: number format: double nullable: true description: Dictionary mapping quantity names to date-to-value mappings assets: type: array items: $ref: '#/components/schemas/BacktestAsset' nullable: true comparison_index_returns: type: object additionalProperties: type: string format: decimal pattern: ^-?\d{0,5}(?:\.\d{0,10})?$ nullable: true description: >- Dictionary mapping dates (yyyy-mm-dd) to the return values of a reference index. BacktestResolvedParamsRebalancePeriodEnum: enum: - MONTHLY - WEEKLY type: string description: |- * `MONTHLY` - MONTHLY * `WEEKLY` - WEEKLY BacktestAsset: type: object description: Serializer for individual asset entries in backtest results. properties: symbol: type: string TILT_ASSET_ID: type: string nullable: true optimized_weight: type: object additionalProperties: type: number format: double nullable: true benchmark_weight: type: object additionalProperties: type: number format: double nullable: true unrealized_pnl_gain: type: object additionalProperties: type: number format: double nullable: true unrealized_pnl_loss: type: object additionalProperties: type: number format: double nullable: true wash_sale_aware_loss: type: object additionalProperties: type: number format: double nullable: true required: - symbol securitySchemes: ProAPIToken: type: apiKey in: header name: X-Api-Key ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.