> ## Documentation Index > Fetch the complete documentation index at: https://docs.ca.cryptoprocessing.com/llms.txt > Use this file to discover all available pages before exploring further. # Get a fixed exchange quote > Get a fixed exchange quote for a specific amount, to use with [/v2/exchange/fixed](/api-reference/endpoints/exchange-fixed). A quote is valid for `fix_period` seconds (until `ts_release`) and for one [/v2/exchange/fixed](https://docs.ca.cryptoprocessing.com/api-reference/endpoints/exchange-fixed.md) request. Getting a quote doesn't check or reserve your balance. For every error this endpoint returns and what it means, see [API errors: Get a fixed exchange quote](https://docs.ca.cryptoprocessing.com/api-reference/errors.md#get-a-fixed-exchange-quote). ## OpenAPI ````yaml POST /v2/exchange/calculate openapi: 3.1.0 info: title: Merchant Backend V2 version: '1.0' description: Documentation for merchant backend processing endpoints servers: - url: https://app.ca.cryptoprocessing.com/api security: - xProcessingKey: [] tags: - name: Status - name: Balance - name: Currencies - name: Deposit addresses - name: Withdrawal - name: Exchange - name: Invoices - name: Transactions paths: /v2/exchange/calculate: post: tags: - Exchange summary: Get an exchange quote description: >- Get a fixed exchange quote for a specific amount, to use with [/v2/exchange/fixed](/api-reference/endpoints/exchange-fixed). operationId: post-exchange-calculate parameters: - $ref: '#/components/parameters/XProcessingSignatureHeader' requestBody: content: application/json: schema: type: object properties: sender_currency: type: string description: >- Currency to exchange from. For a list of all available currencies, see [API currency codes](/api-reference/currency-codes). receiver_currency: type: string description: >- Currency to exchange to. For a list of all available currencies, see [API currency codes](/api-reference/currency-codes). sender_amount: oneOf: - type: string - type: number description: > The amount you want to exchange, in `sender_currency`, as a decimal string (for example, `"100"`) or a number. Include either this parameter or `receiver_amount`, not both. Up to 8 decimal places, or fewer for some currency pairs. The minimum is the `min_amount` of `sender_currency` in [/v2/currencies/rates](/api-reference/endpoints/currencies-rates). receiver_amount: oneOf: - type: string - type: number description: > The amount you want to receive, in `receiver_currency`, before the exchange fee, as a decimal string (for example, `"100"`) or a number. Include either this parameter or `sender_amount`, not both. Up to 8 decimal places, or fewer for some currency pairs. The minimum is the `min_amount` of `receiver_currency` in [/v2/currencies/rates](/api-reference/endpoints/currencies-rates), for the pair in the opposite direction. required: - sender_currency - receiver_currency examples: "Get a quote to convert 100\_USDC to USD": value: sender_currency: USDC receiver_currency: USD sender_amount: 100 "Get a quote to receive 100\_USD for USDC": value: sender_currency: USDC receiver_currency: USD receiver_amount: 100 "Get a quote to convert 0.01\_ETH to USDC": value: sender_currency: ETH receiver_currency: USDC sender_amount: '0.01' description: '' responses: '200': description: OK content: application/json: schema: type: object properties: data: type: object properties: sender_currency: type: string description: The currency being exchanged from. sender_amount: type: string description: >- The amount exchanged from `sender_currency`: the `sender_amount` from the request, or the amount calculated for the `receiver_amount` you sent. It doesn't include the exchange fee (see `fee_amount`). receiver_currency: type: string description: The currency being exchanged to. receiver_amount: type: string description: >- The amount the exchange gives in `receiver_currency`: the `receiver_amount` from the request, or the amount calculated for the `sender_amount` you sent. It's the amount before the exchange fee: if the fee is charged in `receiver_currency`, the amount added to your balance is `receiver_amount` − `fee_amount`. fee_currency: type: string description: >- The currency the exchange fee is charged in: `sender_currency` or `receiver_currency`. fee_amount: type: string description: >- The exchange fee. If it's charged in `sender_currency`, the amount taken from your balance is `sender_amount` + `fee_amount`; if it's charged in `receiver_currency`, the amount added to your balance is `receiver_amount` − `fee_amount`. `0.00000000` when no fee is charged, for example for an exchange between the same currency on different networks. price: type: string description: "The quoted exchange rate: units of `receiver_currency` for\_1\_unit of `sender_currency`, with\_8\_decimal places, so `sender_amount` × `price` can differ slightly from `receiver_amount`. Pass it to `/v2/exchange/fixed` exactly as returned." example: '0.99978134' ts_fixed: type: integer description: >- Unix timestamp, in seconds, when the quote rate was fixed. ts_release: type: integer description: Unix timestamp, in seconds, when the quote expires. fix_period: type: integer description: >- How long the fixed quote remains valid, in seconds. After this period, request a new quote. examples: "Get a quote to convert 100\_USDC to USD": value: data: sender_currency: USDC sender_amount: '100.00000000' receiver_currency: USD receiver_amount: '99.97813400' fee_currency: USD fee_amount: '0.99978134' price: '0.99978134' ts_fixed: 1782219422 ts_release: 1782219482 fix_period: 60 "Get a quote to receive 100\_USD for USDC": value: data: sender_currency: USDC sender_amount: '100.01959184' receiver_currency: USD receiver_amount: '100.00000000' fee_currency: USD fee_amount: '1.00000000' price: '0.99980412' ts_fixed: 1782219490 ts_release: 1782219550 fix_period: 60 "Get a quote to convert 0.01\_ETH to USDC": value: data: sender_currency: ETH sender_amount: '0.01000000' receiver_currency: USDC receiver_amount: '24.64107735' fee_currency: USDC fee_amount: '0.02464107' price: '2464.10773508' ts_fixed: 1782219560 ts_release: 1782219620 fix_period: 60 '400': description: Bad Request. content: application/json: schema: $ref: '#/components/schemas/ValidationOrMalformedJson' examples: Missing sender currency: value: errors: sender_currency: The sender currency field is required. Missing fields: value: errors: receiver_currency: The receiver currency field is required. receiver_amount: >- The receiver amount field is required when the sender amount field is not presented. Same currency on both sides: value: errors: receiver_currency: >- The receiver currency and sender currency must be different. Sender currency doesn't exist: value: errors: sender_currency: The selected sender currency is invalid. Receiver currency doesn't exist: value: errors: receiver_currency: The selected receiver currency is invalid. Both amounts sent: value: errors: receiver_amount: >- The receiver amount field can not be used when the sender amount field is presented. Sender amount not a number: value: errors: sender_amount: The sender amount must be a number. Receiver amount not a number: value: errors: receiver_amount: The receiver amount must be a number. Sender currency not a string: value: errors: sender_currency: The sender currency must be a string. Receiver currency not a string: value: errors: receiver_currency: The receiver currency must be a string. Sender amount zero or negative: value: errors: sender_amount: The sender amount must be greater than 0. Receiver amount zero or negative: value: errors: receiver_amount: The receiver amount must be greater than 0. Sender amount below the minimum: value: errors: sender_amount: The sender_amount must be at least Receiver amount below the minimum: value: errors: receiver_amount: The receiver_amount must be at least Sender amount above the maximum: value: errors: sender_amount: >- The sender_amount may not be greater than Receiver amount above the maximum: value: errors: receiver_amount: >- The receiver_amount may not be greater than Sender amount with too many decimal places: value: errors: sender_amount: We can process only decimal places Receiver amount with too many decimal places: value: errors: receiver_amount: We can process only decimal places Pair not supported or currency not enabled: value: errors: sender_amount: Exchange is unavailable for given currencies Exchange unavailable for the amount: value: errors: sender_amount: >- Unable to exchange the requested amount at the moment. Specify a smaller amount or try again later. Exchange unavailable for the amount to receive: value: errors: receiver_amount: >- Unable to exchange the requested amount at the moment. Specify a smaller amount or try again later. Malformed JSON: value: error: Bad content format code: bad_content_format '403': $ref: '#/components/responses/HeaderAuthorization' '422': $ref: '#/components/responses/InternalError' '429': $ref: '#/components/responses/TooManyRequests' components: parameters: XProcessingSignatureHeader: name: X-Processing-Signature in: header required: true description: >- Hex-encoded HMAC-SHA512 signature of the request body, [generated using your secret key](/api-reference/authentication). schema: type: string schemas: ValidationOrMalformedJson: oneOf: - type: object title: ValidationError description: One or more request parameters failed validation. properties: errors: type: object description: > A map of request field names to a human-readable validation error message for that field. The exact set of possible keys and messages is endpoint-specific — see [API errors](/api-reference/errors#errors-by-endpoint) for the full reference. additionalProperties: type: string description: Human-readable validation error message for this field. - type: object title: MalformedJson description: >- The request body is not valid JSON or the Content-Type header is not set to `application/json`. properties: error: type: string code: type: string responses: HeaderAuthorization: description: | Forbidden content: application/json: schema: type: object properties: error: type: string description: Human-readable error message. code: type: string description: Error code. description: >- Invalid or missing headers, or the API key does not have access to the endpoint. Refer to [Errors](/api-reference/errors#general-errors) for troubleshooting steps. examples: Bad signature header: value: error: Bad signature header code: bad_header_signature API key does not have the required ability: value: error: The API key does not have access to this endpoint. code: api_key_ability_required No signature header: value: error: No signature header code: required_header_signature No key header: value: error: No key header code: required_header_key InternalError: description: > Unprocessable entity. An internal error occurred during processing. The request was understood but could not be completed. The `errors` field is an array of error messages. The `error_code` is always the string `"internal_error"`. content: application/json: schema: type: object required: - errors - error_code properties: errors: type: array description: Array of error messages items: type: string error_code: type: string description: Error code identifier examples: Internal error: value: errors: - Internal error error_code: internal_error Something went wrong: value: errors: - Something went wrong. Please try later. error_code: internal_error Unhandled exception: value: errors: - Something went wrong. error_code: internal_error TooManyRequests: description: > Too Many Requests You sent too many requests in a short time. The limit is counted per API key, so requests from all your servers that use the same key count together. Wait before you send the request again, increasing the delay if you get `429` again, and handle this error by its status code, not by a particular response body. See [Too many requests](/api-reference/errors#too-many-requests-429-too-many-requests). securitySchemes: xProcessingKey: type: apiKey description: Your [API key](/merchant-administration/generate-and-activate-api-keys). in: header name: X-Processing-Key ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.