What is Probe used for?

Probe is a Rust code search and context engine that uses AST-aware parsing and ranking, with CLI, Node.js SDK and MCP modes for AI coding assistants. It is a good fit for giving AI coding agents better code context and searching large codebases from the terminal.

Is Probe open source?

Yes. Probe is open source under the Apache-2.0 licence. Its source code is on GitHub at probelabs/probe and is written mainly in Rust.

Yes. Probe is open source, so the software itself is free to use. Paid plans are also available, starting at $40 per seat per month.

What is Probe an alternative to?

Probe is an open-source alternative to Sourcegraph.

Is Probe actively maintained?

Yes. The most recent commit to Probe was on 1 October 2026, and the latest release is v0.6.0-rc341, published on 1 October 2026. The project has 721 stars on GitHub.

Probe: open-source alternative to Sourcegraph

About Probe

Probe is a code and markdown context engine with a built-in agent, made to work on large codebases. It aims to give AI coding assistants and developers complete, relevant context by treating code as structured code rather than text, combining ripgrep-style speed with tree-sitter AST parsing.

Unlike plain text search tools, it returns whole functions or classes, and unlike embedding-based tools it needs no indexing step or embedding model. Searches use Elasticsearch-style boolean queries ranked with BM25. Probe can be used in several modes: as a Probe Agent exposed over MCP, as raw MCP tools, as a CLI agent, through direct CLI commands or from a Node.js SDK. An LLM scripting feature and a list of supported languages are covered in the documentation.

The project is written in Rust and licensed under Apache-2.0. The authors present it as useful for spec-driven development, code reviews and onboarding, where understanding code comes before writing it. It runs locally on your own machine, with LLM access configured through environment variables.

Key features

AST-aware code search with tree-sitter
Returns complete functions and classes
BM25-ranked boolean queries
No indexing or embedding setup
MCP tools and agent mode
CLI and Node.js SDK

Good fit for

→Giving AI coding agents better code context
→Searching large codebases from the terminal

Built with: Rust
Tags: code-search; mcp; tree-sitter; rust; ai-coding; semantic-search; cli; ripgrep

Probe: questions and answers

What is Probe used for?: Probe is a Rust code search and context engine that uses AST-aware parsing and ranking, with CLI, Node.js SDK and MCP modes for AI coding assistants. It is a good fit for giving AI coding agents better code context and searching large codebases from the terminal.
Is Probe open source?: Yes. Probe is open source under the Apache-2.0 licence. Its source code is on GitHub at probelabs/probe and is written mainly in Rust.
Is Probe free?: Yes. Probe is open source, so the software itself is free to use. Paid plans are also available, starting at $40 per seat per month.
What is Probe an alternative to?: Probe is an open-source alternative to Sourcegraph.
Is Probe actively maintained?: Yes. The most recent commit to Probe was on 1 October 2026, and the latest release is v0.6.0-rc341, published on 1 October 2026. The project has 721 stars on GitHub.