SReverseby Simpa Labs

Android workflow reconstruction · Uploads

Android file upload API reverse engineering

We rebuild the APK’s complete file transfer API, including multipart fields, signed URLs, chunking, encryption, retries and the calls around each transfer.

The upload request is one step in a workflow

An Android upload can begin with a metadata call, continue through a signed storage URL, then finish with a confirmation call. Large files may be split into parts and joined by a final request. The app can also resize an image, encrypt a document, calculate a hash or request a fresh token before sending any bytes.

We trace the file from the Android picker or generated content into the network client. This shows the real filename, media type, form field, byte changes and headers. We also follow the response into the next app action so an uploaded object becomes usable instead of stopping at a successful transfer.

Recover multipart and direct-body uploads

For multipart/form-data, each part has its own headers and content. The boundary separates parts in the body. We recover text fields, file fields, filenames, media types and their exact order when signing depends on the encoded body. Direct uploads may send the raw file with PUT or POST to the API or object store.

  • Map create, upload, complete, status and delete calls.
  • Reproduce multipart bodies, raw uploads and signed URLs.
  • Handle chunk size, part numbers, checksums and resume state.
  • Copy required storage headers without leaking unrelated app headers.
  • Parse progress, processing status and final asset records.

Rebuild the bytes the server expects

The selected file may not be the uploaded file. Android code can rotate an image, remove metadata, transcode media, compress data or wrap it in encryption. We compare input bytes with the request body and trace each transform. Download flows get the same treatment, including range requests, manifests, decryption and integrity checks.

Signatures may cover the content hash, byte length, media type, path and expiry time. A small change can invalidate the upload. The finished clients build the body first, calculate every dependent value in the correct order, then send it with live authentication and retry rules.

The full delivery

You receive a callable API for the full APK in Python and JavaScript/TypeScript, plus a Postman collection. The clients cover every recovered endpoint and workflow. They create fresh signatures, encrypt requests, decrypt responses, keep authentication and session state, and follow the same request order as the app.

Each client includes clear input models, parsed outputs, refresh behavior, uploads, downloads, streaming events and useful errors where the app uses them. We test the delivery against the live service so it runs without copied requests or old tokens.

Reviewed 30 August 2026 · SReverse research desk

One full APK. One complete delivery.

Projects start at $120. Most are delivered in 24 to 72 hours.

Every format included

Python, JavaScript/TypeScript, Postman and complete API documentation cover the same full endpoint set. Your team runs the clients in its own server or system.

Ready in 24–72 hours

The delivery window starts after we receive the APK and any account access needed to run it. The fixed quote states the deadline. Most projects finish sooner.

Deployment checked before the quote

The package includes signing, encryption, decryption and session handling. We verify device-bound keys and server integrity checks during review and document runtime requirements before you commit.

30 days of fixes

Report a defect within 30 days of delivery. We fix any delivered call that does not match the tested APK at no extra cost.

Start your full APK reconstruction

Send the full APK

Projects start at $120. Choose WhatsApp or email, then attach the APK in the app that opens. We reply within one hour with the next step and send the fixed quote after review.

Want us to contact you?