> ## Documentation Index > Fetch the complete documentation index at: https://docs.fincept.in/llms.txt > Use this file to discover all available pages before exploring further. # Binomial Tree Barrier Option > Price barrier options using binomial trees. Barrier options activate (knock-in) or terminate (knock-out) when the underlying crosses a barrier level. **Barrier Types:** - **Down-and-Out**: Terminates if S drops below barrier (is_down=true, is_knock_in=false) - **Down-and-In**: Activates if S drops below barrier (is_down=true, is_knock_in=true) - **Up-and-Out**: Terminates if S rises above barrier (is_down=false, is_knock_in=false) - **Up-and-In**: Activates if S rises above barrier (is_down=false, is_knock_in=true) **Rebate:** Fixed payment if knock-out occurs. **Use Cases:** - Price structured products with barriers - Reduce option premium with knock-out features - Create path-dependent payoffs - Manage risk with barrier structures **Tier:** Standard (2 credits/request) [Tier: PRO, Credits: 5] ## OpenAPI ````yaml api-specs/pricing.json post /quantlib/pricing/binomial/barrier openapi: 3.1.0 info: title: FinceptQuantLib API - Pricing Module description: >- Advanced options pricing models including Black-Scholes, Black76, Bachelier, Kirk spread options, and binomial trees. Standard Tier access required (2 credits per request). version: 3.0.0 contact: name: Fincept API Support url: https://fincept.in servers: - url: https://api.fincept.in description: Fincept API Production Server security: - APIKeyHeader: [] tags: - name: quantlib-pricing description: Advanced options pricing models and Greeks calculation x-displayName: Pricing paths: /quantlib/pricing/binomial/barrier: post: tags: - quantlib-pricing summary: Binomial Tree Barrier Option description: >- Price barrier options using binomial trees. Barrier options activate (knock-in) or terminate (knock-out) when the underlying crosses a barrier level. **Barrier Types:** - **Down-and-Out**: Terminates if S drops below barrier (is_down=true, is_knock_in=false) - **Down-and-In**: Activates if S drops below barrier (is_down=true, is_knock_in=true) - **Up-and-Out**: Terminates if S rises above barrier (is_down=false, is_knock_in=false) - **Up-and-In**: Activates if S rises above barrier (is_down=false, is_knock_in=true) **Rebate:** Fixed payment if knock-out occurs. **Use Cases:** - Price structured products with barriers - Reduce option premium with knock-out features - Create path-dependent payoffs - Manage risk with barrier structures **Tier:** Standard (2 credits/request) [Tier: PRO, Credits: 5] operationId: binomial_barrier requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/BinomialBarrierRequest' example: spot: 100 strike: 105 risk_free_rate: 0.05 dividend_yield: 0.02 volatility: 0.25 time_to_maturity: 1 n_steps: 100 option_type: call barrier: 95 is_knock_in: false is_down: true rebate: 2 method: CRR responses: '200': description: Successful calculation content: application/json: schema: type: object properties: success: type: boolean example: true data: type: object properties: price: type: number description: Barrier option price example: 6.234 barrier: type: number description: Barrier level example: 95 is_knock_in: type: boolean description: True for knock-in, false for knock-out example: false is_down: type: boolean description: True for down barrier, false for up barrier example: true '401': $ref: '#/components/responses/UnauthorizedError' '402': $ref: '#/components/responses/InsufficientCreditsError' '422': $ref: '#/components/responses/ValidationError' components: schemas: BinomialBarrierRequest: type: object required: - spot - strike - risk_free_rate - volatility - time_to_maturity - barrier - is_knock_in - is_down properties: spot: type: number description: Current price of the underlying asset example: 100 strike: type: number description: Strike price of the option example: 105 risk_free_rate: type: number description: Risk-free interest rate (annualized, decimal format) example: 0.05 dividend_yield: type: number description: Continuous dividend yield (annualized, decimal format) example: 0.02 default: 0 volatility: type: number description: Annualized volatility (decimal format) example: 0.25 time_to_maturity: type: number description: Time to expiration in years example: 1 n_steps: type: integer description: Number of time steps in the binomial tree example: 100 default: 100 option_type: type: string enum: - call - put description: Type of option example: call default: call barrier: type: number description: Barrier level that triggers knock-in or knock-out example: 95 is_knock_in: type: boolean description: True for knock-in barrier, false for knock-out barrier is_down: type: boolean description: True for down barrier, false for up barrier rebate: type: number description: Rebate paid if barrier option is knocked out example: 0 default: 0 method: type: string enum: - CRR - JR - LR - TIAN description: Binomial tree method example: CRR default: CRR responses: UnauthorizedError: description: Authentication information is missing or invalid content: application/json: schema: type: object properties: detail: type: string example: Invalid API key InsufficientCreditsError: description: Insufficient API credits for this request content: application/json: schema: type: object properties: detail: type: string example: >- Insufficient credits. This endpoint costs 2 credits per request. ValidationError: description: Request validation failed content: application/json: schema: type: object properties: detail: type: array items: type: object properties: loc: type: array items: type: string msg: type: string type: type: string securitySchemes: APIKeyHeader: type: apiKey in: header name: X-API-Key description: >- API key for authentication. Get your key at https://api.fincept.in/auth/register ````