Documentation

SCIP Precise Navigation Guide

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CodeLens supports SCIP (Source Code Intelligence Protocol) index files for type-aware definitions, references, hover docs, and diagnostics.

Why SCIP?

tree-sitter provides fast, zero-config symbol analysis but operates on syntax alone. SCIP adds type-aware precision:

Capability tree-sitter SCIP
Find definitions Name-based, same file bias Type-resolved, cross-package
Find references Text grep + scope heuristics All usages including re-exports
Hover docs None Full documentation
Diagnostics None Compiler-level diagnostics

Setup

1. Build with SCIP support

cargo build --release --features scip-backend

2. Generate a SCIP index for your project

Use the appropriate SCIP indexer for your language:

# Rust
cargo install scip-cli
scip-rust            # produces index.scip

# Go
go install github.com/sourcegraph/scip-go/cmd/scip-go@latest
scip-go              # produces index.scip

# TypeScript / JavaScript
npm install -g @anthropic-ai/scip-typescript
scip-typescript index # produces index.scip

# Java
# Use scip-java from Sourcegraph
scip-java index      # produces index.scip

# Python
pip install scip-python
scip-python index    # produces index.scip

3. Place the index file

CodeLens auto-detects SCIP index files in these locations (checked in order):

  1. index.scip (project root)
  2. .scip/index.scip
  3. .codelens/index.scip

4. Verify

codelens-mcp . --cmd get_capabilities --args '{}'

Look for "scip" in the intelligence_sources array.

How It Works

When SCIP is available, CodeLens uses it as a precision layer before falling back to tree-sitter:

find_referencing_symbols("MyStruct", "src/main.rs")
  1. Try oxc_semantic (JS/TS only)
  2. Try SCIP backend (if scip-backend feature + index exists)
  3. Fall back to tree-sitter text search

The SCIP backend returns results with backend: "scip" and confidence 0.98 (vs 0.85 for tree-sitter).

Keeping the Index Fresh

SCIP indexes are static snapshots. After significant code changes:

# Re-run the indexer
scip-rust  # or scip-go, scip-typescript, etc.

CodeLens does NOT auto-update the SCIP index. For CI/CD workflows, generate the index as a build step.

Limitations

  • SCIP index must be pre-generated (no on-demand indexing)
  • Index file can be large for big projects (10-100MB+)
  • Not all languages have mature SCIP indexers
  • Hover docs depend on the indexer including documentation in the output