Dobby

Compact Minecraft Bedrock developer client for macOS and Linux mcpelauncher.

It captures packet violations and raw decode evidence, displays entity/player hitboxes, outlines client-known chests and ores, and shows passive network, chunk, and packet-traffic metrics. It also includes an isolated, opt-in cape entitlement test.

In-game diagnostic

Mods > Dobby contains the developer overlay. It shows native PING, client-observed TPS~, loaded chunks and outstanding requests, plus client FPS and resident memory use.

The bottom-right packet overlay shows compact incoming/outgoing packet and byte rates plus cumulative traffic formatted in B, KB, MB, GB, or TB. It appears only while a client world is rendering. Packet traffic toggles it independently from the top-right network metrics.

Chest ESP outlines chests found in Bedrock's decoded client chunk storage. It does not request or modify world data, so concealed chests appear only if the server actually sent them.

Ore ESP incrementally scans client-decoded subchunk palettes for vanilla ores, ancient debris, and mineral storage blocks. Loaded chunks refresh nearest-first when enabled, while nearby chunks are rechecked for live block changes. It never requests or modifies chunk data.

Menu toggles are saved locally and restored on the next launch.

Local cape entitlement test

Put local * (persona).zip cape archives in the ignored capes/ directory. The verified install workflow validates every archive and PNG, decodes each bounded 64×32 RGBA texture, and writes only Dobby's private dobby-capes index and pixel files. It does not edit Bedrock's persona cache, catalog, resource-pack directories, or account data. Previous Dobby cape data is backed up before replacement. Cape assets remain local and are never staged by the publish workflow.

Enable Mods > Dobby > Cape entitlement test before opening the cape picker. For the exact supported build, Dobby validates the native persona manager and PersonaRepository layouts, adds local UUIDs to the manager's in-memory persona_capes vector, and resolves those UUIDs through validated piece-lookup hooks. Disabling the toggle removes the local IDs from that vector. Selecting a local UUID reuses the client's validated Pan Cape piece as a resource template. On equip, Dobby accepts only an exact local cape ID and an exact 64×32 RGBA SerializedSkinImpl layout, copies that cape's local pixels into the shared skin, and marks the outgoing PlayerSkinPacket premium, non-persona, and cape-on-classic. The toggle defaults to off; any target, ABI, ID, image, or vector mismatch leaves mutation disabled.

Target

• Minecraft Android 1.26.40.5
• Full native diagnostics: arm64-v8a, libminecraftpe.so build ID 5893edc8d56c93cbdb50e0f9436320236b78c89d
• Linux compatibility mode: x86_64, libminecraftpe.so build ID f6e1f0c7ee60774ac31d55742e833264e5c27bb4

The ARM64 build validates every target signature and refuses to patch incompatible builds. The Linux x86_64 build deliberately does not install native game hooks; it provides the Dobby launcher menu, saved preferences, FPS, and Linux resident-memory metrics while packet diagnostics, network/chunk hooks, ESP, and cape testing remain unavailable. This fail-closed mode is the base for a future independently verified x86_64 hook port.

Build

./build.sh

Build prerequisites are CMake 3.20+, a C++20 host compiler, make, file, and the Android NDK. Set ANDROID_NDK_HOME when the NDK is not installed in a standard Android SDK location. On Fedora, the host packages are:

sudo dnf install cmake gcc-c++ make file
ANDROID_NDK_HOME="$HOME/Android/Sdk/ndk/28.2.13676358" ./build.sh --local

The default workflow runs release and sanitizer tests, builds the host launcher ABI, audits public content, installs the verified artifact, commits and pushes changes, then starts Minecraft and confirms Dobby is ready. Linux x86_64 and ARM Linux/macOS arm64-v8a are detected automatically; use --abi arm64-v8a or --abi x86_64 to override detection. Use ./build.sh --local for a build-only iteration or ./build.sh --help for individual opt-outs.

The install workflow also enables Dobby in the selected launcher profile. Set DOBBY_LAUNCHER_PROFILE when the launcher has more than one profile. Reinstalling normalizes stale Dobby registrations to one launcher-managed entry.

On macOS, logs default to ~/Library/Application Support/mcpelauncher/. The Linux Flatpak writes them under ~/.var/app/io.mrarm.mcpelauncher/data/mcpelauncher/. Set DOBBY_OUTPUT_DIR to override the output directory. Set DOBBY_LAUNCHER_ROOT when building or installing for a nonstandard launcher data directory. Optional configuration:

• DOBBY_AUTO_POPUP=0 disables automatic violation popups.
• DOBBY_VERBOSE=1 enables verbose developer events.
• DOBBY_HISTORY_LIMIT=100 sets the bounded in-memory history size.
• DOBBY_RAW_CAPTURE_LIMIT=2048 sets the maximum captured packet-body bytes.

Raw captures and logs may contain server-provided data and remain excluded from Git.