Weaver

A semantics-aware command-line tool for AI coding agents.

Weaver is your AI agent's best friend when it comes to understanding and modifying code. We believe the shell should speak the language of semantics—not just bytes and lines—so we've built a tool that brings deep code intelligence to your terminal.

What is Weaver?

Weaver is a Rust-based CLI tool that provides semantic operations on codebases through a simple, composable interface. It follows the UNIX philosophy: small, focused tools that communicate via JSON Lines (JSONL) and play nicely with your existing shell utilities like jq, xargs, and find.

Under the bonnet, Weaver runs a daemon (weaverd) that orchestrates language servers, syntax analysers, and specialised plugins—all sandboxed for safety—while the lightweight CLI (weaver) lets you issue commands and stream results. Whether you're an AI agent planning a refactor or a human debugging a tricky rename, Weaver gives you the semantic primitives you need.

Status

Weaver is in active early development (v0.1.0). We've completed the core foundation—the CLI/daemon architecture, LSP integration for Rust, Python, and TypeScript, and the security sandbox—but there's more to come. Check out our roadmap to see what we're working on next.

Note: The "Double-Lock" safety harness for write operations is still under development. We recommend caution when using act commands until this is complete.

Key features

• Semantic operations as shell verbs — Commands like observe get-definition and act rename-symbol bring IDE-level intelligence to your terminal.
• JSONL-native protocol — Every request and response is a JSON object, making integration with other tools trivial.
• Multi-layer fusion — Combines Language Server Protocol (LSP), Tree-sitter parsing, and call graph analysis for comprehensive code understanding.
• Zero-trust sandboxing — External tools run in isolated environments using Linux namespaces and seccomp-bpf filters.
• Graceful degradation — When a capability isn't available, Weaver tells you what's missing and suggests alternatives.

Components

Weaver is organised as a Cargo workspace with five crates:

Crate	Description
weaver-cli	Thin CLI client that serialises commands into JSONL
weaverd	Daemon broker that orchestrates backends and verifies operations
weaver-config	Shared configuration management via ortho-config
weaver-lsp-host	Language Server Protocol host with capability detection
weaver-sandbox	Security sandbox wrapper around birdcage

Getting started

Here's the quickest path to your first Weaver command:

# Start the daemon
weaver daemon start

# Query a symbol definition
weaver observe get-definition --uri file:///path/to/main.rs --position 42:17

# Check daemon status
weaver daemon status

# Stop the daemon when you're done
weaver daemon stop

For full installation, configuration, and usage instructions, please see the User's Guide. It covers daemon lifecycle management, configuration layering, and the complete command reference.

Building from source

Weaver requires the pinned Nightly Rust toolchain nightly-2026-03-26 for local builds. The workspace .cargo/config.toml uses options that require the Nightly toolchain, so stable Rust is not sufficient for local Cargo builds in this checkout. To build:

cargo +nightly-2026-03-26 build --release

To run the test suite:

cargo +nightly-2026-03-26 test --workspace

Toolchain prerequisites

The workspace .cargo/config.toml enables Nightly-only build settings for the Cranelift codegen backend in development builds. Install the pinned toolchain and component with:

rustup toolchain install nightly-2026-03-26
rustup component add rustc-codegen-cranelift --toolchain nightly-2026-03-26

Set a local override so Cargo uses that pinned Nightly automatically in this checkout:

rustup override set nightly-2026-03-26

If any of these prerequisites are missing, the failure mode is often opaque: Cargo may report unstable -Z option errors or missing rustc-codegen-cranelift. When that happens, verify the pinned Nightly toolchain and the Cranelift component first.

If local builds fail, verify the pinned Nightly override first, then confirm the Cranelift component is installed before investigating the workspace itself.

Documentation

• User's Guide — Configuration, daemon lifecycle, and command reference
• Design Document — Architecture, philosophy, and technical deep-dive
• Roadmap — Development phases and upcoming features

Licence

Weaver is released under the ISC License.