Google AX is an open-source agent harness and execution orchestrator developed by Google. It provides runtime infrastructure and execution sandboxing designed to bridge terminal-based tool environments with Google's Antigravity agent architecture and Gemini/Vertex AI model backends. Day-to-day, AX operates as a command-line harness (`cmd/ax`) interfacing with a local sidecar service. The system manages conversational state across interactions, maintaining persistent execution directories (`AX_HARNESS_WORKDIR`) and routing tool executions such as shell commands, code generation, and repository edits. It communicates with language models primarily through Google Cloud Vertex AI and the Google GenAI SDK ecosystem. What distinguishes AX from conventional standalone CLI agents is its decoupled harness architecture. Instead of tightly coupling model calls with the user terminal, AX implements a client-sidecar model that enforces workspace boundaries, isolates execution environments (including support for sandboxed/gVisor environments), and cleanly serializes conversation turns to durable storage for session resumption. Google AX is open-source software distributed under an Apache 2.0 license. Model inference costs depend on your underlying Google Cloud Vertex AI or Google AI Studio billing configuration.
Tags: agent harness, AI, ai agent, cli, developer tools, OpenSource
AX_HARNESS_WORKDIR) so command executions and relative path resolutions do not drift into the ambient process directory. - Vertex AI native integration — Connects directly to Google's model infrastructure using standard environment variables (GOOGLE_GENAI_USE_VERTEXAI, GOOGLE_CLOUD_PROJECT, and GOOGLE_CLOUD_LOCATION). - Durable session persistence — Manages conversation turns in segmented state directories, enabling safe resumption and state retention across runs. - Built-in diagnostics — Includes an ax doctor command to inspect, validate, and troubleshoot local sidecar connections, runtime dependencies, and asset integrity.Google AX is built for systems engineers, AI tooling developers, and enterprise platform teams implementing sandboxed, repeatable agent execution workflows on top of Google Cloud Vertex AI. It is less suited for end users looking for a plug-and-play, single-binary interactive chat UI without infrastructure setup.
bash git clone https://github.com/google/ax.git cd ax go build -o ax ./cmd/ax Ensure Python and required runtime dependencies (google-antigravity) are installed in your environment.bash export GOOGLE_GENAI_USE_VERTEXAI=true export GOOGLE_CLOUD_PROJECT="your-gcp-project-id" export GOOGLE_CLOUD_LOCATION="us-central1" export AX_HARNESS_WORKDIR="$(pwd)" # Run the diagnostic tool to verify environment and sidecar health ./ax doctorbash ./ax run "Audit the repository for broken unit tests and apply necessary fixes"Part of CLI Coding Agents
Categories: AI Coding Agents, Chatbot Development, Developer Tools