diff --git a/Blueye.Protocol.Protobuf.csproj b/Blueye.Protocol.Protobuf.csproj
index 4fd72837..fc49fb7d 100644
--- a/Blueye.Protocol.Protobuf.csproj
+++ b/Blueye.Protocol.Protobuf.csproj
@@ -13,8 +13,8 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Google.Protobuf" Version="3.33.4" />
-    <PackageReference Include="Google.Protobuf.Tools" Version="3.33.4">
+    <PackageReference Include="Google.Protobuf" Version="3.33.5" />
+    <PackageReference Include="Google.Protobuf.Tools" Version="3.33.5">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
diff --git a/CLAUDE.md b/CLAUDE.md
new file mode 100644
index 00000000..3f3ae27d
--- /dev/null
+++ b/CLAUDE.md
@@ -0,0 +1,75 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+Protocol definition repository for Blueye Robotics underwater drones. The core definitions live in `protobuf_definitions/*.proto` (proto3 syntax) and are compiled into language-specific libraries for C++, Python, TypeScript, and C#/.NET.
+
+Published packages:
+- **npm**: `@blueyerobotics/protocol-definitions`
+- **NuGet**: `Blueye.Protocol.Protobuf` (GitHub Packages)
+- **Python**: `blueye.protocol` (PyPI, via separate repo triggered by CI)
+
+## Build Commands
+
+### C++ (CMake)
+```
+cmake -B build && cmake --build build
+cmake --install build --prefix /usr/local
+```
+
+### TypeScript
+```
+pnpm install
+# Generate TypeScript from proto files:
+mkdir -p ./out/ && protoc protobuf_definitions/*.proto \
+  --plugin=./node_modules/.bin/protoc-gen-ts_proto \
+  --proto_path=protobuf_definitions \
+  --ts_proto_out=./out \
+  --ts_proto_opt=outputIndex=true \
+  --ts_proto_opt=globalThisPolyfill=true \
+  --ts_proto_opt=useExactTypes=false
+# Compile TypeScript:
+pnpm run build
+```
+
+### C#/.NET
+```
+dotnet pack Blueye.Protocol.Protobuf.csproj -c Release -o out
+```
+
+### Linting
+```
+# Via Docker:
+./protolint.sh
+```
+Protolint runs on every push/PR in CI. Configuration in `.protolint.yaml` (max line length: 120 chars).
+
+### Documentation Generation
+```
+./protoc-gen-doc.sh
+```
+
+## Proto File Structure
+
+All proto definitions are in `protobuf_definitions/`:
+- **message_formats.proto** — Main message types, enums, and parameter definitions (largest file)
+- **telemetry.proto** — Telemetry message definitions
+- **control.proto** — Control command messages
+- **req_rep.proto** — Request/response message patterns
+- **mission_planning.proto** — Mission planning messages
+- **aquatroll.proto** — AquaTroll sensor-specific messages
+
+## CI/CD Pipeline
+
+- **ci-build.yaml** — Protolint validation (all pushes and PRs)
+- **ci-typescript.yaml** — Generate TS, compile, publish to npm (master only)
+- **ci-dotnet.yaml** — Build and publish NuGet package (all pushes)
+- **ci-python.yaml** — Triggers `blueye.protocol` repo update via repository dispatch (master, when proto files change)
+- **gen-docs.yaml** — Generate HTML docs, upload to Azure (master only)
+
+## Code Style
+
+- 2-space indentation, trim trailing whitespace (`.editorconfig`)
+- Proto files: max 120 character line length (`.protolint.yaml`)
diff --git a/protobuf_definitions/message_formats.proto b/protobuf_definitions/message_formats.proto
index 213c26ed..837ace0b 100644
--- a/protobuf_definitions/message_formats.proto
+++ b/protobuf_definitions/message_formats.proto
@@ -1313,3 +1313,29 @@ message SurfaceUnitBatteryInfo {
 message SurfaceUnitVersionInfo {
   string version = 1; // Surface Unit firmware version (x.y.z).
 }
+
+// Bounding box for object detection.
+//
+// Coordinates are in pixels relative to the camera image,
+// where (x, y) is the top-left corner of the bounding box.
+message BoundingBox {
+  uint32 x = 1; // Horizontal offset of the top-left corner (px).
+  uint32 y = 2; // Vertical offset of the top-left corner (px).
+  uint32 width = 3; // Width of the bounding box (px).
+  uint32 height = 4; // Height of the bounding box (px).
+}
+
+// A single object detection from a computer vision model.
+message ObjectDetection {
+  BoundingBox bounding_box = 1; // Bounding box of the detected object.
+  float confidence = 2; // Detection confidence score (0..1).
+  uint32 class_id = 3; // Numeric class identifier from the model.
+  string class_name = 4; // Human-readable class name.
+  uint32 tracking_id = 5; // Unique ID for tracking the same object across frames.
+}
+
+// A list of object detections from a single video frame.
+message ObjectDetections {
+  repeated ObjectDetection detections = 1; // List of detections in the frame.
+  Camera camera = 2; // Which camera the detections are from.
+}
diff --git a/protobuf_definitions/telemetry.proto b/protobuf_definitions/telemetry.proto
index 724784a4..bdc75558 100644
--- a/protobuf_definitions/telemetry.proto
+++ b/protobuf_definitions/telemetry.proto
@@ -313,3 +313,8 @@ message LogEntryTel {
     KernelLogEntry kernel = 2; // Kernel log entry.
   }
 }
+
+// Object detections from a computer vision model.
+message ObjectDetectionsTel {
+  ObjectDetections object_detections = 1; // List of object detections from a video frame.
+}