> ## Documentation Index > Fetch the complete documentation index at: https://docs.aiinsurance.io/llms.txt > Use this file to discover all available pages before exploring further. # Endorse Policy Transaction > Applies an ENDORSE transaction to an existing policy. Endorsements modify policy state over specified date ranges using per-field deltas. Each delta targets a specific path within the policy data (e.g. `policy.annualPremium`, `policy.exposures`) and can Add, Remove, or Overwrite values. Deltas come in two flavors: - **`deltas`** — segmented deltas for per-segment fields. Each delta specifies a `startDate` / `endDate` within the policy term. - **`fullTermDeltas`** — deltas for cross-segment invariant fields (`fullTermPolicyBilling`, `fullTermPolicyInfo`, `fullTermPolicyRatingResponse`, `fullTermExposureRatingResponse`). These are applied uniformly across the entire policy term, so no dates are accepted — the server injects `policyStartDate` → `policyEndDate` automatically. Mixing the two is a validation error: `fullTerm*` paths in `deltas` are rejected, and non-`fullTerm*` paths in `fullTermDeltas` are rejected. At least one of the two arrays must be non-empty. The engine recomputes segments after applying all deltas — adjacent segments with identical data are automatically merged. The response includes the full set of resulting segments. **Required permission:** `company.policy:update` ## OpenAPI ````yaml /openapi/generated-external-api.yaml post /api/v1/external/companies/{companyId}/policies/{policyId}/transaction/endorse openapi: 3.0.3 info: title: AI Insurance External API description: External API for AI Insurance platform version: 1.0.0 contact: email: support@aiinsurance.io servers: - url: https://app.aiinsurance.io description: Production security: - ApiKeyAuth: [] paths: /api/v1/external/companies/{companyId}/policies/{policyId}/transaction/endorse: post: tags: - Field Model Policy Transactions summary: Endorse Policy Transaction description: > Applies an ENDORSE transaction to an existing policy. Endorsements modify policy state over specified date ranges using per-field deltas. Each delta targets a specific path within the policy data (e.g. `policy.annualPremium`, `policy.exposures`) and can Add, Remove, or Overwrite values. Deltas come in two flavors: - **`deltas`** — segmented deltas for per-segment fields. Each delta specifies a `startDate` / `endDate` within the policy term. - **`fullTermDeltas`** — deltas for cross-segment invariant fields (`fullTermPolicyBilling`, `fullTermPolicyInfo`, `fullTermPolicyRatingResponse`, `fullTermExposureRatingResponse`). These are applied uniformly across the entire policy term, so no dates are accepted — the server injects `policyStartDate` → `policyEndDate` automatically. Mixing the two is a validation error: `fullTerm*` paths in `deltas` are rejected, and non-`fullTerm*` paths in `fullTermDeltas` are rejected. At least one of the two arrays must be non-empty. The engine recomputes segments after applying all deltas — adjacent segments with identical data are automatically merged. The response includes the full set of resulting segments. **Required permission:** `company.policy:update` operationId: endorsePolicyTransaction parameters: - $ref: '#/components/parameters/companyId' - $ref: '#/components/parameters/policyIdPath' requestBody: required: true content: application/json: schema: type: object required: - effectiveDate properties: effectiveDate: type: string format: date description: | The effective date of the endorsement in ISO 8601 format. transactionTimestamp: type: string format: date-time description: > When the business decision was made. Defaults to the current time if omitted. Set explicitly for imports (e.g., aligning to a bordereau booking date). deltas: type: array description: > Per-segment deltas. Each delta specifies a date range (`startDate` / `endDate`) within the policy term, a path within the policy data, an action (Add, Remove, or Overwrite), and the new value. Paths targeting `fullTerm*` fields must be sent via `fullTermDeltas` instead. items: type: object required: - startDate - endDate - path - action - value properties: startDate: type: string format: date description: >- Start of the date range this delta applies to. Must be `<=` endDate. endDate: type: string format: date description: End of the date range this delta applies to. path: type: string description: > Dot-delimited path into the policy data (e.g. `policy.annualPremium`, `policy.exposures`, `policy.exposures[].bedCount`). Must not target a `fullTerm*` field — use `fullTermDeltas` for those. action: type: string enum: - Add - Remove - Overwrite description: > Delta action. `Overwrite` overwrites the value at the path. `Add` appends to an array with set semantics (e.g. adding an exposure; no-op if already present). `Remove` removes matching values from a collection — objects are matched by `id`, primitives by equality. If the value is not present, the delta is a no-op. value: description: >- The new value to set at the path. Type depends on the field. fullTermDeltas: type: array description: > Cross-segment invariant deltas. Each delta targets a `fullTerm*` path (`policy.fullTermPolicyBilling`, `policy.fullTermPolicyInfo`, `policy.fullTermPolicyRatingResponse`, `policy.fullTermExposureRatingResponse`). The server applies each delta across the entire policy term — no `startDate` / `endDate` is accepted. Paths not matching a `fullTerm*` prefix are rejected. items: type: object required: - path - action - value properties: path: type: string description: | Dot-delimited path into a `fullTerm*` field (e.g. `policy.fullTermPolicyBilling`, `policy.fullTermPolicyBilling.policyPremium`). action: type: string enum: - Add - Remove - Overwrite description: > Delta action. Same semantics as segmented deltas. `Overwrite` is the typical choice; `Add` / `Remove` work against list fields inside a `fullTerm*` object. value: description: The new value at the path. examples: midTermPremiumChange: summary: Mid-term premium adjustment value: effectiveDate: '2025-04-01' deltas: - startDate: '2025-04-01' endDate: '2025-12-31' path: policy.annualPremium action: Overwrite value: 102000 fullTermDeltas: - path: policy.fullTermPolicyBilling action: Overwrite value: policyPremium: 102000 policyTaxes: 0 policyFees: 500 policyGrandTotal: 102500 addExposure: summary: Add exposure mid-term value: effectiveDate: '2025-06-01' deltas: - startDate: '2025-06-01' endDate: '2025-12-31' path: policy.exposures action: Add value: id: 550e8400-e29b-41d4-a716-446655440020 exposureType: MedicalFacility bedCount: 80 fullTermDeltas: - path: policy.fullTermPolicyBilling action: Overwrite value: policyPremium: 120000 policyTaxes: 0 policyFees: 500 policyGrandTotal: 120500 withTimestamp: summary: Endorsement with explicit transaction timestamp value: effectiveDate: '2025-04-01' transactionTimestamp: '2025-03-28T14:30:00Z' deltas: - startDate: '2025-04-01' endDate: '2025-12-31' path: policy.customPolicyText action: Overwrite value: updated value fullTermOnly: summary: Billing-only endorsement (no per-segment changes) value: effectiveDate: '2025-04-01' fullTermDeltas: - path: policy.fullTermPolicyBilling.policyPremium action: Overwrite value: 98000 - path: policy.fullTermPolicyBilling.policyGrandTotal action: Overwrite value: 98500 responses: '201': description: Endorsement applied successfully content: application/json: schema: $ref: '#/components/schemas/PolicyTransactionVersionResponse' examples: success: summary: Endorsement transaction response value: policyId: 550e8400-e29b-41d4-a716-446655440001 policyVersion: 2 transactionId: 550e8400-e29b-41d4-a716-446655440030 startDate: '2025-01-01' endDate: '2025-12-31' createdAt: '2025-04-01T10:30:00.000Z' fullTermPolicyInfo: policyStatus: active policyStartDate: year: 2025 month: 1 day: 1 timezone: America/New_York policyEndDate: year: 2025 month: 12 day: 31 timezone: America/New_York primaryInsuredId: 550e8400-e29b-41d4-a716-446655440010 fullTermPolicyBilling: policyPremium: 102000 policyTaxes: 0 policyFees: 500 policyGrandTotal: 102500 segments: - startDate: '2025-01-01' endDate: '2025-03-31' fieldModelV1Data: policy: annualPremium: 85000 fullTermPolicyInfo: policyStatus: active policyStartDate: year: 2025 month: 1 day: 1 timezone: America/New_York policyEndDate: year: 2025 month: 12 day: 31 timezone: America/New_York primaryInsuredId: 550e8400-e29b-41d4-a716-446655440010 fullTermPolicyBilling: policyPremium: 102000 policyTaxes: 0 policyFees: 500 policyGrandTotal: 102500 - startDate: '2025-04-01' endDate: '2025-12-31' fieldModelV1Data: policy: annualPremium: 102000 fullTermPolicyInfo: policyStatus: active policyStartDate: year: 2025 month: 1 day: 1 timezone: America/New_York policyEndDate: year: 2025 month: 12 day: 31 timezone: America/New_York primaryInsuredId: 550e8400-e29b-41d4-a716-446655440010 fullTermPolicyBilling: policyPremium: 102000 policyTaxes: 0 policyFees: 500 policyGrandTotal: 102500 '400': description: Validation error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: emptyDeltas: summary: No deltas provided value: error: code: InvalidRequest message: At least one delta is required noExistingVersion: summary: Policy has no NEW_BUSINESS transaction value: error: code: InvalidRequest message: >- Policy has no existing version — NEW_BUSINESS must be created first deltaOutsidePolicyPeriod: summary: Delta date range outside policy term value: error: code: InvalidDelta message: >- Delta date range [2026-06-01, 2026-12-31] falls outside policy period [2025-01-01, 2025-12-31] deltaStartAfterEnd: summary: Delta startDate after endDate value: error: code: InvalidDelta message: >- Delta startDate (2025-12-31) must be <= endDate (2025-01-01) fullTermPathInDeltas: summary: fullTerm path sent via deltas value: error: code: InvalidDelta message: >- Invalid deltas path "policy.fullTermPolicyBilling.policyPremium" — fullTerm paths must be sent via fullTermDeltas, not deltas nonFullTermPathInFullTermDeltas: summary: Non-fullTerm path sent via fullTermDeltas value: error: code: InvalidDelta message: >- Invalid fullTermDeltas path "policy.customPolicyText" — must target one of: policy.fullTermPolicyBilling, policy.fullTermPolicyInfo, policy.fullTermPolicyRatingResponse, policy.fullTermExposureRatingResponse '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '404': description: Policy not found content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: policyNotFound: summary: Policy does not exist value: error: code: NOT_FOUND message: Policy 550e8400-e29b-41d4-a716-446655440099 not found '500': $ref: '#/components/responses/InternalServerError' components: parameters: companyId: name: companyId in: path required: true schema: type: string format: uuid description: Company identifier policyIdPath: name: policyId in: path required: true schema: type: string format: uuid description: Policy identifier schemas: PolicyTransactionVersionResponse: type: object description: > Response returned by policy transaction endpoints. Contains the policy version produced by the transaction, including all derived segments. required: - policyId - policyVersion - transactionId - startDate - endDate - createdAt - segments properties: policyId: type: string format: uuid description: Policy identifier policyVersion: type: integer description: Sequential version number produced by this transaction transactionId: type: string format: uuid description: Identifier of the transaction that produced this version startDate: type: string format: date description: Policy term start date (ISO 8601) endDate: type: string format: date description: Policy term end date (ISO 8601) createdAt: type: string format: date-time description: When the transaction was created (ISO 8601) fullTermPolicyInfo: type: object nullable: true description: > Full-term policy information. Contains policy status, term dates, and primary insured reference. additionalProperties: true fullTermPolicyBilling: type: object nullable: true description: > Full-term billing aggregates. Contains premium, taxes, fees, and grand total for the full policy term. additionalProperties: true segments: type: array description: > Derived segments for this policy version. Each segment represents a maximal contiguous date range where policy state is identical. Adjacent segments with identical data are automatically merged. items: $ref: '#/components/schemas/PolicyTransactionSegmentResponse' ErrorResponse: type: object description: Standard error response for all external API endpoints required: - error properties: error: type: object required: - code - message properties: code: type: string description: Machine-readable error code example: VALIDATION_ERROR message: type: string description: Human-readable error message example: 'submissionId: Required field is missing' details: type: array description: Additional details for validation errors (field-level errors) items: type: object properties: field: type: string description: The field that caused the error example: submissionId message: type: string description: Description of the field error example: Required field is missing PolicyTransactionSegmentResponse: type: object description: > A derived policy segment representing a date range where policy state is identical. Contains the full policy data (policy-level fields and nested exposures) for this period. required: - startDate - endDate - fieldModelV1Data properties: startDate: type: string format: date description: Segment start date (ISO 8601) endDate: type: string format: date description: Segment end date (ISO 8601) fieldModelV1Data: type: object description: > Policy state for this segment. Contains a `policy` key with policy-level fields and a nested `exposures` array. properties: policy: type: object description: Policy-level fields and nested exposures for this segment. additionalProperties: true additionalProperties: true responses: Unauthorized: description: Unauthorized - Invalid or missing API key content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: missingApiKey: summary: Missing API key value: error: code: UNAUTHORIZED message: Authorization header is required bearerTokenNotAllowed: summary: Bearer token used instead of API key value: error: code: UNAUTHORIZED message: External API endpoints require API key authentication Forbidden: description: Forbidden - Insufficient permissions content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: insufficientPermissions: summary: Insufficient permissions value: error: code: FORBIDDEN message: Insufficient permissions to perform this action InternalServerError: description: Internal Server Error - Unexpected error occurred content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: internalError: summary: Unexpected server error value: error: code: INTERNAL_ERROR message: An unexpected error occurred. Please try again later. securitySchemes: ApiKeyAuth: type: apiKey in: header name: Authorization description: >- API key authentication. Include your API key in the Authorization header. ````