Getting Started
From zero to sub-millisecond search in under 5 minutes. No configuration files. No daemons to set up manually. Just build and go.
New in v1.10.0:
ig --top N "pattern"— BM25 ranking returns the N most relevant files instead of the first N found on disk. See CLI reference.ig --semantic "error"— PMI-learned query expansion (no ML model, synonyms learned from your repo during indexing). See CLI reference.- Auto-compact output when piped to an agent + dir-aggregate
ig smart <dir>andig files. See vs rtk bench: ig now beats rtk on total bytes and total wall time.
Prerequisites
- Rust toolchain (stable) —
rustup toolchain install stable - Cargo (comes with Rust)
- A terminal and a project to search through
Installation
The fastest way to install ig is via the one-line installer. It downloads the latest release binary and auto-configures your AI agents.
# Install latest release + auto-configure AI agents
curl -fsSL https://raw.githubusercontent.com/MakFly/instant-grep/main/install.sh | bashOr via Homebrew:
brew install MakFly/tap/igOr build from source:
# Clone and build
git clone https://github.com/MakFly/instant-grep
cd instant-grep
cargo build --release
# Copy to PATH
cp target/release/ig ~/.local/bin/ig
# Verify
ig --versionTip: Make sure ~/.local/bin is in your $PATH.
Add export PATH="$HOME/.local/bin:$PATH" to your shell config if needed.
Configure AI agents
If you used the one-line installer, agents are already configured. Otherwise run:
# Auto-configure Claude Code, Codex, Gemini CLI...
ig setup
# ig setup does the following:
# - Installs ig-rewrite.sh hook in ~/.claude/hooks/
# - Registers the hook in ~/.claude/settings.json
# - Adds Bash(ig *) permission for Claude Code
# - Adds search tools section to ~/.claude/CLAUDE.mdBuild your first index
Navigate to any project directory and run ig index.
This creates a .ig/ directory with binary index files
and auto-generated project artifacts.
$ ig index .
* Scanning directory tree
* Skipping 38 excluded directories (node_modules, target, .git, ...)
* Building sparse n-gram index: 1,552 files (SPIMI, 2 segments)
+ Index built in 450ms
lexicon: 31 MB (.ig/lexicon.bin)
postings: 7.1 MB (.ig/postings.bin)
metadata: 111 KB (.ig/metadata.bin)Your first search
Run ig with any regex pattern. If no index exists, it builds one automatically.
Shortcut: ig "pattern" is equivalent to ig search "pattern".
The search subcommand is optional.
# Basic search
ig "async fn" src/
# Case-insensitive search
ig -i "TODO" .
# With context lines
ig -C 3 "Result<T>" .
# JSON output for AI agents
ig --json "impl Trait" .
# Filter by file type
ig --type rs "pub fn" .How auto-build works
When you run ig search, it checks if a .ig/ index
exists in the target directory. If not, it automatically runs ig index first.
You can always just run search — no manual indexing required.
ig "pattern" .called- Check for
.ig/metadata.bin— if missing, build index first - Extract n-grams from regex, query posting lists, verify matches
- Results printed in ~0.9ms