> For clean Markdown of any page, append .md to the page URL. > For a complete documentation index, see https://docs.getsinbad.com/llms.txt. > For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.getsinbad.com/_mcp/server. # Upload payment proof POST https://us-central1-sinbad-staging-env.cloudfunctions.net/b2b-v1/v1/trades/{tradeId}/proof Content-Type: application/json Upload payment proof. **Credential:** Customer session **Before you call** - A customer session for the same partner, integration, customer, wallet and chain. - To change proof, the customer must be the fiat payer on a BUY, and the trade must be CREATED, PAID or DISPUTED. - Uploads accept PNG or JPEG files up to 3 MiB decoded. Authenticated reads return merchant originals unchanged. Customer BUY fiat payer only in CREATED, PAID or DISPUTED. One PNG or JPEG image up to 3 MiB. PDFs are rejected for new uploads. Identical POST retry is idempotent; use PATCH for replacement. Stored privately with a small blurred preview; a linked proof message is committed atomically. Does not mark paid. Storage unavailability can return 502 or 503 UPSTREAM_ERROR. Retry with backoff; contact Sinbad with requestId if it persists. > Confirm with Sinbad that this endpoint is enabled in your environment. **Errors** | Status | Code | What to do | | --- | --- | --- | | 400 | `VALIDATION_ERROR` | Correct the fields reported in details before retrying. | | 401 | `UNAUTHENTICATED` | Create a new customer session or use a valid server credential. | | 403 | `FORBIDDEN` | Check credential ownership, integration and the supplied Origin. | | 404 | `NOT_FOUND` | Check the resource ID. A resource that belongs to someone else also returns 404. | | 409 | `CONFLICT` | Read the current state again before you prepare or retry. | | 502 | `UPSTREAM_ERROR` | Retry with backoff and quote requestId if it persists. For transaction reports, retry the same hash without sending another transaction. | | 503 | `UPSTREAM_ERROR` | Retry with backoff; preserve the same idempotency key for a repeated mutation. | Reference: https://docs.getsinbad.com/api-reference/payment-proof/upload-partner-trade-proof ## Authentication - `Authorization` header (bearer token, required) — Bearer authentication of the form `Bearer `, where token is your auth token. ## Request ### Path parameters - `tradeId` (string, required) ### Body (application/json) This endpoint expects an object. - `contentType` (enum, required) - Allowed values: `image/png`, `image/jpeg` - `dataBase64` (string, required) — Base64 encoded file bytes without a data URL prefix. ## Response ### 201 Saved proof metadata, including identical retries. - `proofId` (string, required) - `contentType` (string, required) — Original content type; merchant files can use native image formats. - `size` (integer, required) - `uploadedByRole` (enum, required) - Allowed values: `customer`, `merchant` - `uploadedAt` (datetime, required, nullable) - `base64` (string, required) — Blurred preview, not original file bytes. - `width` (double, required) - `height` (double, required) ## Errors ### 400 Bad Request Error The request is invalid. - `error` (V1TradesTradeIdProofPostResponsesContentApplicationJsonSchemaError, required) ### 401 Unauthorized Error Authentication is required. - `error` (V1TradesTradeIdProofPostResponsesContentApplicationJsonSchemaError, required) ### 403 Forbidden Error You do not have permission to perform this action. - `error` (V1TradesTradeIdProofPostResponsesContentApplicationJsonSchemaError, required) ### 404 Not Found Error The requested resource was not found. - `error` (V1TradesTradeIdProofPostResponsesContentApplicationJsonSchemaError, required) ### 409 Conflict Error The request conflicts with the current state of the resource. - `error` (V1TradesTradeIdProofPostResponsesContentApplicationJsonSchemaError, required) ### 502 Bad Gateway Error A required service is unavailable. - `error` (V1TradesTradeIdProofPostResponsesContentApplicationJsonSchemaError, required) ### 503 Service Unavailable Error Service temporarily unavailable. - `error` (V1TradesTradeIdProofPostResponsesContentApplicationJsonSchemaError, required) ## Types ### V1TradesTradeIdProofPostResponsesContentApplicationJsonSchemaError - `code` (string, required) - `numericId` (integer, required) - `message` (string, required) - `requestId` (string, optional) - `details` (map from string to any, optional) ## Examples **Request** ```json { "contentType": "image/png", "dataBase64": "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO+/lS8AAAAASUVORK5CYII=" } ``` **Response** ```json { "proofId": "proof_demo", "contentType": "image/png", "size": 68, "uploadedByRole": "customer", "uploadedAt": "2026-10-23T10:00:00.000Z", "base64": "/9j/2wBDABQODxIPDRQSEBIXFRQYHjIhHhwcHj0sLiQySUBMS0dARkVQWnNiUFVtVkVGZIhlbXd7gYKBTmCNl4x9lnN+gXz/2wBDARUXFx4aHjshITt8U0ZTfHx8fHx8fHx8fHx8fHx8fHx8fHx8fHx8fHx8fHx8fHx8fHx8fHx8fHx8fHx8fHx8fHz/wAARCABAAEADASIAAhEBAxEB/8QAFQABAQAAAAAAAAAAAAAAAAAAAAb/xAAUEAEAAAAAAAAAAAAAAAAAAAAA/8QAFAEBAAAAAAAAAAAAAAAAAAAAAP/EABQRAQAAAAAAAAAAAAAAAAAAAAD/2gAMAwEAAhEDEQA/ALMAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAH/2Q==", "width": 1, "height": 1 } ``` **SDK Code** ```python Default import requests url = "https://us-central1-sinbad-staging-env.cloudfunctions.net/b2b-v1/v1/trades/trade_demo/proof" payload = { "contentType": "image/png", "dataBase64": "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO+/lS8AAAAASUVORK5CYII=" } headers = { "Authorization": "Bearer ", "Content-Type": "application/json" } response = requests.post(url, json=payload, headers=headers) print(response.json()) ``` ```javascript Default const url = 'https://us-central1-sinbad-staging-env.cloudfunctions.net/b2b-v1/v1/trades/trade_demo/proof'; const options = { method: 'POST', headers: {Authorization: 'Bearer ', 'Content-Type': 'application/json'}, body: '{"contentType":"image/png","dataBase64":"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO+/lS8AAAAASUVORK5CYII="}' }; try { const response = await fetch(url, options); const data = await response.json(); console.log(data); } catch (error) { console.error(error); } ``` ```go Default package main import ( "fmt" "strings" "net/http" "io" ) func main() { url := "https://us-central1-sinbad-staging-env.cloudfunctions.net/b2b-v1/v1/trades/trade_demo/proof" payload := strings.NewReader("{\n \"contentType\": \"image/png\",\n \"dataBase64\": \"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO+/lS8AAAAASUVORK5CYII=\"\n}") req, _ := http.NewRequest("POST", url, payload) req.Header.Add("Authorization", "Bearer ") req.Header.Add("Content-Type", "application/json") res, _ := http.DefaultClient.Do(req) defer res.Body.Close() body, _ := io.ReadAll(res.Body) fmt.Println(res) fmt.Println(string(body)) } ``` ```ruby Default require 'uri' require 'net/http' url = URI("https://us-central1-sinbad-staging-env.cloudfunctions.net/b2b-v1/v1/trades/trade_demo/proof") http = Net::HTTP.new(url.host, url.port) http.use_ssl = true request = Net::HTTP::Post.new(url) request["Authorization"] = 'Bearer ' request["Content-Type"] = 'application/json' request.body = "{\n \"contentType\": \"image/png\",\n \"dataBase64\": \"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO+/lS8AAAAASUVORK5CYII=\"\n}" response = http.request(request) puts response.read_body ``` ```java Default import com.mashape.unirest.http.HttpResponse; import com.mashape.unirest.http.Unirest; HttpResponse response = Unirest.post("https://us-central1-sinbad-staging-env.cloudfunctions.net/b2b-v1/v1/trades/trade_demo/proof") .header("Authorization", "Bearer ") .header("Content-Type", "application/json") .body("{\n \"contentType\": \"image/png\",\n \"dataBase64\": \"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO+/lS8AAAAASUVORK5CYII=\"\n}") .asString(); ``` ```php Default request('POST', 'https://us-central1-sinbad-staging-env.cloudfunctions.net/b2b-v1/v1/trades/trade_demo/proof', [ 'body' => '{ "contentType": "image/png", "dataBase64": "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO+/lS8AAAAASUVORK5CYII=" }', 'headers' => [ 'Authorization' => 'Bearer ', 'Content-Type' => 'application/json', ], ]); echo $response->getBody(); ``` ```csharp Default using RestSharp; var client = new RestClient("https://us-central1-sinbad-staging-env.cloudfunctions.net/b2b-v1/v1/trades/trade_demo/proof"); var request = new RestRequest(Method.POST); request.AddHeader("Authorization", "Bearer "); request.AddHeader("Content-Type", "application/json"); request.AddParameter("application/json", "{\n \"contentType\": \"image/png\",\n \"dataBase64\": \"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO+/lS8AAAAASUVORK5CYII=\"\n}", ParameterType.RequestBody); IRestResponse response = client.Execute(request); ``` ```swift Default import Foundation let headers = [ "Authorization": "Bearer ", "Content-Type": "application/json" ] let parameters = [ "contentType": "image/png", "dataBase64": "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO+/lS8AAAAASUVORK5CYII=" ] as [String : Any] let postData = JSONSerialization.data(withJSONObject: parameters, options: []) let request = NSMutableURLRequest(url: NSURL(string: "https://us-central1-sinbad-staging-env.cloudfunctions.net/b2b-v1/v1/trades/trade_demo/proof")! as URL, cachePolicy: .useProtocolCachePolicy, timeoutInterval: 10.0) request.httpMethod = "POST" request.allHTTPHeaderFields = headers request.httpBody = postData as Data let session = URLSession.shared let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in if (error != nil) { print(error as Any) } else { let httpResponse = response as? HTTPURLResponse print(httpResponse) } }) dataTask.resume() ```