> ## Documentation Index > Fetch the complete documentation index at: https://docs.go.aiinsurance.io/llms.txt > Use this file to discover all available pages before exploring further. # Merge Payee > Repoints every non-deleted invoice linked to `{payeeId}` at `toPayeeId`, in ONE transaction — the merge composition. Per linked invoice: `payment_removed ×k → payee_changed → payment_recorded ×k` (invoices without live payments take just the middle step). Re-recorded marks copy amount / date / memo / line item / erode flag verbatim under NEW server-minted payment ids — EXCEPT payments whose removal composed a reserve unwind (reset-absorbed erosion), which re-record NON-eroding so reserves are not eroded twice. **Idempotent by convergence.** All member actions are server-derived (no client `actionId`s, no `If-Match`): a retry finds nothing linked to the merged payee and emits nothing (`journalIds: []`). **Selector vs target.** `{payeeId}` is a pure selector — an id with no linked invoices converges to an empty merge; `toPayeeId` must exist (`422 LINK_TARGET_MISSING`) and must differ from `{payeeId}` (a schema-level `400`). **Required permission:** `company.payment:update` ## OpenAPI ````yaml /openapi/generated-external-api.yaml post /api/v1/companies/{companyId}/financials/payees/{payeeId}/merge 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://go.aiinsurance.io description: Production security: - ApiKeyAuth: [] paths: /api/v1/companies/{companyId}/financials/payees/{payeeId}/merge: post: tags: - Financials summary: Merge Payee description: | Repoints every non-deleted invoice linked to `{payeeId}` at `toPayeeId`, in ONE transaction — the merge composition. Per linked invoice: `payment_removed ×k → payee_changed → payment_recorded ×k` (invoices without live payments take just the middle step). Re-recorded marks copy amount / date / memo / line item / erode flag verbatim under NEW server-minted payment ids — EXCEPT payments whose removal composed a reserve unwind (reset-absorbed erosion), which re-record NON-eroding so reserves are not eroded twice. **Idempotent by convergence.** All member actions are server-derived (no client `actionId`s, no `If-Match`): a retry finds nothing linked to the merged payee and emits nothing (`journalIds: []`). **Selector vs target.** `{payeeId}` is a pure selector — an id with no linked invoices converges to an empty merge; `toPayeeId` must exist (`422 LINK_TARGET_MISSING`) and must differ from `{payeeId}` (a schema-level `400`). **Required permission:** `company.payment:update` operationId: mergeFinancialsPayee parameters: - $ref: '#/components/parameters/companyId' - name: payeeId in: path required: true schema: type: string format: uuid description: >- The payee being merged AWAY — a pure selector; every invoice linked to it is repointed requestBody: required: true content: application/json: schema: type: object additionalProperties: false required: - toPayeeId properties: toPayeeId: type: string format: uuid description: >- The surviving payee every linked invoice is repointed to; must exist and differ from `{payeeId}` author: type: string minLength: 1 maxLength: 255 description: >- Optional display label for the source system's author (e.g. the integrator-side user). Stamped as the journal record's display attribution; the acting principal stays the External API service user, so a label can never impersonate an in-app user. Ignored on idempotent replays examples: merge: summary: Merge one payee into another value: toPayeeId: 550e8400-e29b-41d4-a716-446655440211 responses: '200': description: >- Every emitted journal id, in execution order — empty on a converged retry (nothing left linked to the merged payee) content: application/json: schema: type: object required: - journalIds properties: journalIds: type: array items: type: string format: uuid description: Every emitted journal id, in execution order examples: merged: summary: One paid invoice repointed (remove -> repoint -> re-record) value: journalIds: - 6d8e0f2a-4b5c-4d7e-9f1a-0b2c3d4e5f6a - 7e9f1a3b-5c6d-4e8f-0a2b-1c3d4e5f6a7b - 8f0a2b4c-6d7e-4f9a-1b3c-2d4e5f6a7b8c converged: summary: A retry converges to an empty merge value: journalIds: [] '400': description: >- Bad Request — a malformed payload or a self-merge (`toPayeeId` equal to the path payee) content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: selfMerge: summary: Self-merge rejected value: error: code: VALIDATION_ERROR message: 'toPayeeId: toPayeeId must differ from the merged payee' userMessages: - 'toPayeeId: toPayeeId must differ from the merged payee' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '404': description: >- Not Found — the company does not have this financials surface enabled (the endpoint behaves as if it does not exist). An unknown MERGED payee is not a 404: it converges to an empty merge content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: notFound: summary: Not found value: error: code: NotFoundError message: Not found userMessages: - Not found '422': $ref: '#/components/responses/FinancialsV2PreconditionFailed' '500': $ref: '#/components/responses/InternalServerError' components: parameters: companyId: name: companyId in: path required: true schema: type: string format: uuid description: Company identifier schemas: 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' userMessages: type: array description: >- Clean, verbatim-displayable messages — one entry per failure, free of error-code tags, field paths, and internal noise. Suitable for showing to end users as-is. items: type: string example: - Exposures of type 'company' require an address 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 FinancialsV2PreconditionError: type: object description: >- A failed write precondition (`422`): the request was well-formed but the books reject it. Preconditions fail closed — a rejected write leaves no journal record, no ledger change, and no read-state change. `error.code` is one of the STABLE financials error codes (single source: `FINANCIALS_V2_PRECONDITION_CODES` in the engine's error module, re-exported to this surface as `FINANCIALS_V2_API_ERROR_CODES`) — messages may be reworded, the codes will not. required: - error properties: error: type: object required: - code - message properties: code: type: string enum: - LIVE_PAYMENTS - AMOUNT_EXCEEDS_BALANCE_DUE - INVALID_AMOUNT - LINE_ITEMS_IMMUTABLE - INVOICE_DELETED - INVOICE_VOIDED - INVOICE_DRAFT - INVOICE_NOT_DRAFT - PAYMENT_NOT_FOUND - ERODE_RESERVES_MISMATCH - ERODE_REQUIRES_EVENT - DEPRECATED_CONFIG - NOT_RESERVED_CATEGORY - FUTURE_DATE - UNKNOWN_ID - LINK_TARGET_MISSING - UNAPPROVE_PAID - NOT_APPROVED - POLICY_INVOICE_BATCH_ONLY description: >- The stable precondition code — one per guard. `LIVE_PAYMENTS` (the action — re-link, payee change, or void — needs the invoice's live payments removed first); `AMOUNT_EXCEEDS_BALANCE_DUE` (a payment mark's magnitude overshoots its line item's remaining — per line, never a document scalar); `INVALID_AMOUNT` (a zero mark, or a mark whose sign opposes its line item's open remaining — a `payBalanceDue` against a document with nothing open included); `LINE_ITEMS_IMMUTABLE` (a posted invoice's line items — ids, types, amounts — and its category are fixed from the posting moment: any post-posting change is rejected, at any payment count; corrections are void-and-recreate, payments removed first; drafts edit freely until finalize); `INVOICE_DELETED` / `INVOICE_VOIDED` (lifecycle closures); `INVOICE_DRAFT` (drafts are unposted — money may not touch one: recording a payment on or voiding a draft is rejected; finalize it first); `INVOICE_NOT_DRAFT` (finalize targets exactly a draft); `PAYMENT_NOT_FOUND` (no live payment mark with that id on that invoice); `ERODE_RESERVES_MISMATCH` / `ERODE_REQUIRES_EVENT` (the erode flag missing on a reserved category or present on operating; eroding needs a linked event — there is no headroom bound: the remaining reserve is a signed balance and may cross zero); `DEPRECATED_CONFIG` / `NOT_RESERVED_CATEGORY` / `UNKNOWN_ID` (cited configuration guards); `FUTURE_DATE`; `LINK_TARGET_MISSING` (the named link target does not exist); `UNAPPROVE_PAID` (an approval cannot be revoked once payments have been recorded — remove them first); `NOT_APPROVED` (money cannot post against an unapproved invoice AND the calling key does not hold `company.payment:approve`, so it cannot approve it either — a key that holds the permission auto-approves instead of failing here); `POLICY_INVOICE_BATCH_ONLY` (the write touches a POLICY-LINKED invoice's document — creating one with `links.policy`, or updating, voiding, restoring, deleting, or re-linking one that is already policy-linked. A policy's invoices are issued as one set so that every price component of the policy's pricing contract stays netted to its own line item, so they are written only by the policy invoice batch: `POST /api/v1/companies/{companyId}/financials/policies/{policyId}/invoices/batch`. Change the policy or submit an explicit batch and the invoices are reissued. Payments, payee changes, and approvals on a policy invoice are unaffected) message: type: string description: Human-readable description of the failed precondition userMessages: type: array description: Clean, verbatim-displayable messages items: type: string 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: AuthenticationError message: API key authentication required userMessages: - API key authentication required invalidApiKey: summary: >- Invalid API key (e.g. unknown key, or a Bearer token used instead of an API key) value: error: code: AuthenticationError message: Invalid API key userMessages: - Invalid API key Forbidden: description: Forbidden - Insufficient permissions content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: insufficientPermissions: summary: Insufficient permissions value: error: code: AuthorizationError message: User is not authorized to perform the requested action userMessages: - User is not authorized to perform the requested action companyMismatch: summary: A valid API key naming another company in the URL value: error: code: AuthorizationError message: API key is not scoped to the requested company userMessages: - API key is not scoped to the requested company FinancialsV2PreconditionFailed: description: >- Unprocessable — a write precondition failed. Fails closed: no journal record, no ledger change, no read-state change. `error.code` is one of the stable financials error codes; each operation's description names its signature codes. content: application/json: schema: $ref: '#/components/schemas/FinancialsV2PreconditionError' examples: livePayments: summary: The action requires the invoice's live payments removed first value: error: code: LIVE_PAYMENTS message: >- The invoice has live payments; remove them before this action userMessages: - >- The invoice has live payments; remove them before this action unknownId: summary: >- A cited configuration id is unknown (or outside the cited category) value: error: code: UNKNOWN_ID message: lineItemTypeId does not belong to the cited category userMessages: - lineItemTypeId does not belong to the cited category policyInvoiceBatchOnly: summary: >- Policy-linked invoice documents are changed only as one policy batch value: error: code: POLICY_INVOICE_BATCH_ONLY message: >- Policy-linked invoice documents can only be changed through POST /api/v1/companies/{companyId}/financials/policies/{policyId}/invoices/batch userMessages: - >- Policy-linked invoice documents can only be changed through POST /api/v1/companies/{companyId}/financials/policies/{policyId}/invoices/batch 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: UncaughtActionError message: Uncaught error occurred in userMessages: - An unexpected error occurred. Please try again later. securitySchemes: ApiKeyAuth: type: apiKey in: header name: Authorization description: >- API key authentication. Send your raw API key as the `Authorization` header value with NO scheme prefix — `Authorization: YOUR-API-KEY`. Do NOT prefix it with `Bearer ` or `ApiKey `, and do not use an `X-API-Key` header; those are not accepted. ````