> ## Documentation Index > Fetch the complete documentation index at: https://docs.flextell.ai/llms.txt > Use this file to discover all available pages before exploring further. # Preview the expected value derived from treatments > Returns what creating a lead with these treatments and no `expected_value` would store, or what changing an existing lead's treatments to this set would store, without saving anything. One shared currency is kept with today's TCMB rate; mixed currencies are converted into the clinic's base currency. A treatment whose currency has no recorded rate is left out and listed in `skipped_treatment_ids`. Re-saving a lead with its unchanged treatments keeps its stored value and rate instead. Reading treatment prices here needs only the lead form permissions, not `View:Treatment`. ## OpenAPI ````yaml post /v1/leads/expected-value/preview openapi: 3.1.0 info: title: Flextell API version: 0.0.1 description: >- Flextell REST API referansı. Kimlik doğrulama, scope ve istek kuralları için API sekmesindeki rehberlere bakın. servers: - url: https://app.flextell.ai/api description: Üretim security: - oauth2: [] - bearer: [] paths: /v1/leads/expected-value/preview: post: tags: - Lead summary: Preview the expected value derived from treatments description: >- Returns what creating a lead with these treatments and no `expected_value` would store, or what changing an existing lead's treatments to this set would store, without saving anything. One shared currency is kept with today's TCMB rate; mixed currencies are converted into the clinic's base currency. A treatment whose currency has no recorded rate is left out and listed in `skipped_treatment_ids`. Re-saving a lead with its unchanged treatments keeps its stored value and rate instead. Reading treatment prices here needs only the lead form permissions, not `View:Treatment`. operationId: lead.previewExpectedValue parameters: - name: X-Tenant in: header required: true description: >- Tenant identifier. Send the Tenant ID in the `X-Tenant` header to scope API requests to a specific tenant. schema: type: number requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/LeadExpectedValuePreviewRequest' responses: '200': description: '' content: application/json: schema: type: object properties: success: type: string data: $ref: '#/components/schemas/LeadExpectedValuePreviewResource' required: - success - data '401': $ref: '#/components/responses/AuthenticationException' '403': $ref: '#/components/responses/AuthorizationException' '422': $ref: '#/components/responses/ValidationException' '428': description: >- Mandatory setup is incomplete. Finish the setup wizard first; `data.next_step` names the step to continue with. content: application/json: schema: type: object properties: success: type: boolean examples: - false error_code: type: string enum: - SETUP_REQUIRED examples: - SETUP_REQUIRED message: type: string examples: - Complete the required setup steps to continue. data: type: object properties: next_step: type: - string - 'null' examples: - clinic_info required: - next_step required: - success - error_code - message - data components: schemas: LeadExpectedValuePreviewRequest: type: object properties: treatment_ids: type: array description: >- The active treatment identifiers the lead form has selected. An empty array previews a lead without treatments. items: type: integer description: An active treatment identifier belonging to the tenant. maxItems: 200 required: - treatment_ids title: LeadExpectedValuePreviewRequest LeadExpectedValuePreviewResource: type: object properties: expected_value: type: string description: >- The expected value a lead with these treatments would store, in `currency_code`, formatted like the lead's own `expected_value`. currency_code: type: string description: >- The code of the currency the lead would store: the treatments' shared currency, or the clinic's base currency when they are priced in several. exchange_rate: type: string description: >- The rate of `currency_code` against the clinic's base currency that the lead would freeze, formatted like the lead's own `exchange_rate`. base_currency_expected_value: type: number description: >- The expected value in the clinic's base currency (`expected_value` × `exchange_rate`). rate_date: type: - string - 'null' description: >- The day of the TCMB rate used to convert a treatment price (`Y-m-d`); null when no price needed converting. skipped_treatment_ids: type: array description: >- Treatments left out of the total because their currency has no recorded rate. items: type: integer required: - expected_value - currency_code - exchange_rate - base_currency_expected_value - rate_date - skipped_treatment_ids title: LeadExpectedValuePreviewResource responses: AuthenticationException: description: Unauthenticated content: application/json: schema: type: object properties: message: type: string description: Error overview. required: - message AuthorizationException: description: Authorization error content: application/json: schema: type: object properties: message: type: string description: Error overview. required: - message ValidationException: description: Validation error content: application/json: schema: type: object properties: message: type: string description: Errors overview. errors: type: object description: A detailed description of each field that failed validation. additionalProperties: type: array items: type: string required: - message - errors securitySchemes: oauth2: type: oauth2 flows: authorizationCode: authorizationUrl: https://app.flextell.ai/oauth/authorize tokenUrl: https://app.flextell.ai/oauth/token scopes: '*': all bearer: type: http scheme: bearer ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.