# APKTool MCP — Render-hosted

Hosted FastMCP adapter for [zinja-coder/apktool-mcp-server](https://github.com/zinja-coder/apktool-mcp-server).

## Active deployment

Render free web service: [apktool-mcp-giraffe](https://dashboard.render.com/web/srv-dbiggaek1f9s73d4fbrg). The live service URL is `https://apktool-mcp-giraffe.onrender.com`.

The remote MCP endpoint is `https://apktool-mcp-giraffe.onrender.com/private/<MCP_PATH_TOKEN>/mcp`. The private token is stored in the Render environment and must not be committed to this public repository. ChatGPT plugin authentication is set to No authentication because access is controlled by the private URL path.

### Direct ChatGPT attachment support

1. Attach an APK file in a ChatGPT conversation that has this custom MCP plugin enabled.
2. Ask ChatGPT to call `import_apk_attachment` with the attachment. The tool uses OpenAI `_meta["openai/fileParams"]` and a temporary signed file URL.
3. Pass the returned `apk_path` to `decode_apk`; inspect and modify as needed, then call `build_apk`.
4. Pass the rebuilt output path to `get_apk_download_link`. The server returns a short-lived HTTPS download URL.

ChatGPT attachment imports and temporary artifact downloads are limited to **512 MB** (matching ChatGPT's documented per-file limit). The server streams files to disk to avoid holding the entire APK in RAM; large decodes can still run out of memory on the free Render instance (512 MB RAM). Uploaded files are validated as APK archives. All workspaces and URLs for built APK downloads are ephemeral. Render free services sleep after approximately **15 minutes of inactivity**, destroying temporary files. To wake, visit `https://apktool-mcp-giraffe.onrender.com/health` and re-import the APK if needed.

**Connection note:** Existing ChatGPT custom plugin installations might need a tool refresh or reconnect to discover the newly added attachment and download tools. A successful MCP tool-list response verifies the backend, not ChatGPT's client-side attachment forwarding.

### Backblaze B2 persistent storage (optional)

The Render MCP still works without B2. With B2 configured, attachment imports automatically save originals to a **private B2 bucket**, and `get_apk_download_link` saves output files and provides a one-hour private pre-signed download URL. B2 tools also allow saved files and edited project snapshots to be listed and restored after Render sleeps. A snapshot is explicit: after modifying smali/resources, call `b2_save_project_snapshot(project_dir)` before Render sleeps. Restore with `b2_restore_project_snapshot(object_key)`. Use `b2_delete_saved_object(object_key)` to permanently remove an artifact and its stored versions when you no longer need it.

Create a **read/write application key restricted to the intended bucket** at Backblaze B2 → Application Keys. Store these environment variables **only in Render → Environment**, never in chat or GitHub:

| Variable | Value |
| --- | --- |
| `B2_BUCKET` | Exact private bucket name |
| `B2_S3_ENDPOINT` | S3 endpoint shown by Backblaze, e.g. `https://s3.us-west-004.backblazeb2.com` |
| `B2_KEY_ID` | Restricted application **Key ID** |
| `B2_APPLICATION_KEY` | Restricted application **Application Key** (secret) |

The account's **master key is not S3-compatible**. Set all four fields together and choose **Save, rebuild and deploy** in Render; no MCP URL change is required. Verify with `b2_storage_status` (must report `configured: true`).

The adapter has an **application-side 9 GB soft ceiling** for *current objects stored under* `apktool/` and uses unique keys to avoid normal overwrite-version growth. This is **not an account-wide Backblaze spending cap**, does not count previous object versions or other bucket contents, and cannot guarantee no charges. Configure independent Backblaze Caps & Alerts, keep the bucket private, and set lifecycle rules if needed. A free Render instance has limited RAM/disk and can be suspended for heavy service-originated traffic; persistent B2 storage does not increase processing capacity.

### Run on Render

The deployed Python start command is `uvicorn server:app --host 0.0.0.0 --port ${PORT:-10000}`.
Runtime dependencies are in `requirements.txt`. Render environment variables include `MCP_PATH_TOKEN` (a random secret) and `PUBLIC_BASE_URL` (the HTTPS origin). Do not upload private APKs to a public GitHub repository.

### Credits

Fork-derived adaptation of [zinja-coder/apktool-mcp-server](https://github.com/zinja-coder/apktool-mcp-server), Apache 2.0. The original license is retained in `LICENSE`. Use only for APKs you own or are authorized to analyze.

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## Historical notes (MCPHosting.io)

# APKTool MCP — hosted adapter

A hosting-ready adaptation of [zinja-coder/apktool-mcp-server](https://github.com/zinja-coder/apktool-mcp-server) for deployment on [MCPHosting.io](https://app.mcphosting.io/) and connection to ChatGPT.

**Status:** GitHub source prepared; cloud deployment and end-to-end operation **not yet verified**.

## MCPHosting project setup

Sign in at https://app.mcphosting.io/ and select **Projects → New project**.

| Field | Enter |
| --- | --- |
| Project name | `apktool-mcp` |
| Source | GitHub |
| Public GitHub URL | `https://github.com/stupidgiraffe/apktool-mcp-hosted` |
| Branch/tag | `main` |

Click **Deploy**. The hosted entrypoint now exposes only the FastMCP `mcp` object and lets the provider manage the HTTP listener; it must not start a second process on port 3000. If `EADDRINUSE` persists after this commit, check provider logs or contact their support. If successful, use the dashboard's actual HTTPS `/mcp` endpoint to connect ChatGPT.

Use the single auto-discovery entrypoint `server.py`, which exports `mcp` (FastMCP). MCPHosting must start the HTTP listener itself. For local standalone development use `fastmcp run server.py --transport http --port 8000`. Running `python server.py` intentionally does not start a listener.

## Runtime

- The original `apktool_mcp_server.py` code is retained with an argument-parser adjustment to support imports.
- `requirements.txt` installs FastMCP and a portable Java 21 runtime via `jdk4py`.
- On startup, a local `apktool` command shim is installed into temporary storage. On its first invocation, it downloads official Apktool 3.0.3 and verifies the publisher's SHA-256.
- Decoded APK projects are kept in temporary storage, which might disappear across requests or restarts.

## Limitations and security

The host's dependency installation, outbound download access, runtime limits, and MCP tool behavior still need testing. The original MCP tools accept **paths on the host**, not automatically APKs on your phone or attached in ChatGPT. Convenient remote APK import/export needs a separate mechanism.

Before enabling the connection, ensure your hosted MCP endpoint is protected by authentication. It exposes file inspection and modification capabilities; do not make it openly callable.

## Credits

[zinja-coder/apktool-mcp-server](https://github.com/zinja-coder/apktool-mcp-server) — Apache 2.0 license retained in `LICENSE`. [Apktool](https://apktool.org/) is separately maintained. Use only on APKs you are authorized to analyze or modify.