> ## Documentation Index > Fetch the complete documentation index at: https://docs.arcuserp.com/llms.txt > Use this file to discover all available pages before exploring further. # List exchange rates (NOT IMPLEMENTED) > **NOTICE: Multi-currency support is NOT implemented in Arcus.** This endpoint accepts reads for forward-compatibility but exchange rate data has no business effect on any transaction. All GL posting paths operate in a single functional currency (USD). Storing exchange rates here does NOT cause Arcus to convert invoice amounts, revalue open AR/AP balances, or post FX gain/loss journal entries. Those mechanisms do not exist in Arcus today. This endpoint returns HTTP 501 Not Implemented unless `entities.settings.multi_currency_enabled` is true (which no entity has set, as of 2026-05-22). Returns all exchange rate records for the entity, sorted by effective date descending. Each record includes the source currency code, target currency code (the entity's functional currency), rate value, and effective date. Multiple rates for the same currency pair may exist with different effective dates; the most recent rate before a transaction date is used. Requires `settings:read` scope. ## OpenAPI ````yaml /openapi.yaml get /exchange-rates openapi: 3.1.0 info: title: Arcus ERP Public API version: 1.0.0 description: > Arcus ERP public REST API. Designed for external integrations and data migration. **Authentication.** Bearer token (API key) via the `Authorization` header. Format: `Authorization: Bearer ark_live_ent__` (or `ark_test_*` for sandbox). API keys are issued per-entity in **Settings > Developers > API Keys**. **Entity scoping.** The entity is encoded in the API key prefix; routes are flat (e.g. `/v1/accounts`, `/v1/orders`, `/v1/products`). A small set of platform endpoints (migration, reconciliation, events, webhook endpoints, API keys) use the `/v1/entities/{entity_id}/...` form -- those are noted in their tags. **Key capabilities.** - Related-resource hydration via `?expand[]=` (see `x-arcus-expand` on each resource). - Cursor-based pagination (`starting_after` / `ending_before` / `limit`). - Idempotency via the `Idempotency-Key` header. - Webhook events for asynchronous notification. - Conditional requests / ETag for cache validation. servers: - url: https://api.arcuserp.com/v1 description: Arcus ERP API (accepts both live `ark_live_*` and test `ark_test_*` keys) - url: https://dev-api.arcuserp.com/v1 description: >- Dev sandbox API (test-only data, accepts `ark_test_*` keys against dev RDS) security: [] paths: /exchange-rates: get: tags: - Masters summary: List exchange rates (NOT IMPLEMENTED) description: > **NOTICE: Multi-currency support is NOT implemented in Arcus.** This endpoint accepts reads for forward-compatibility but exchange rate data has no business effect on any transaction. All GL posting paths operate in a single functional currency (USD). Storing exchange rates here does NOT cause Arcus to convert invoice amounts, revalue open AR/AP balances, or post FX gain/loss journal entries. Those mechanisms do not exist in Arcus today. This endpoint returns HTTP 501 Not Implemented unless `entities.settings.multi_currency_enabled` is true (which no entity has set, as of 2026-05-22). Returns all exchange rate records for the entity, sorted by effective date descending. Each record includes the source currency code, target currency code (the entity's functional currency), rate value, and effective date. Multiple rates for the same currency pair may exist with different effective dates; the most recent rate before a transaction date is used. Requires `settings:read` scope. operationId: listExchangeRates parameters: - name: limit in: query schema: type: integer default: 50 - name: after in: query schema: type: string - name: from_currency in: query description: Filter by source currency. Accepts ISO-4217 code (e.g. USD) or UUID. schema: type: string - name: to_currency in: query description: Filter by target currency. Accepts ISO-4217 code (e.g. GBP) or UUID. schema: type: string - name: from_currency_id in: query description: >- Filter by source currency UUID (canonical form). Use from_currency for code-based lookup. schema: type: string format: uuid - name: to_currency_id in: query description: Filter by target currency UUID (canonical form). schema: type: string format: uuid - name: as_of_date_gte in: query schema: type: string format: date - name: as_of_date_lte in: query schema: type: string format: date responses: '200': description: List of exchange rates content: application/json: schema: type: object properties: object: type: string example: list data: type: array items: type: object has_more: type: boolean url: type: string example: /v1/exchange-rates '401': $ref: '#/components/responses/Error' '403': $ref: '#/components/responses/Error' security: - ApiKeyAuth: [] components: responses: Error: description: Error response (400/401/403/404/409/422/429/500) content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' schemas: ErrorEnvelope: type: object description: | Canonical error response envelope. All API errors use this shape. required: - error - code properties: error: type: string description: Machine-readable error key example: not_found code: type: string description: Machine-readable error code (often same as error) example: not_found type: type: string enum: - validation_error - permission_error - not_found - conflict - rate_limit - internal - expand_error - not_implemented example: not_found hint: type: string description: Human-readable one-sentence explanation (English) example: >- The requested order does not exist or does not belong to this entity. param: type: string description: The parameter that caused the error, if applicable example: expand[0] required: type: string description: The scope required (only on insufficient_scope errors) example: accounts:read request_id: type: string description: >- Unique request ID for support tracing (maps to CloudWatch log stream) example: req_abc123 securitySchemes: ApiKeyAuth: type: http scheme: bearer description: | API key issued per entity via Settings > Developers > API Keys. Each key carries scopes (e.g. orders:read, products:write). Bearer token format: Authorization: Bearer ark_live_ent__ Test keys use ark_test_ent__. Both are issued per entity via Settings > Developers > API Keys. ````