cicada-mcp 0.4.1

An Elixir module search MCP server

CICADA

Code Intelligence: Contextual Analysis, Discovery, and Attribution

Give your AI assistant structured access to your Elixir codebase.

Quick Install · Security · Developers · AI Assistants · Docs

---

Why CICADA?

Traditional AI assistants treat your repo like a pile of text. That leads to:

• Token waste: blind grep dumps that burn 3k+ tokens per question.
• Hallucinated edits: aliases/imports hide call sites, so refactors miss real usages.
• No historical context: design intent and PR trade-offs never make it into the prompt.

CICADA is an MCP server that gives assistants AST-level knowledge:

• Module + function definitions with signatures, specs, docs, owning files.
• Complete call-site tracking (aliases, imports, dynamic references).
• Semantic/keyword search so you can ask for "authentication" even if it's called verify_credentials/2.
• Git + PR attribution to surface why code exists.
• Dead-code detection and module dependency views for safe refactors.

Result: in our comparison, the same question dropped from 3,127 tokens / 52.8s to 550 tokens / 35s with correct answers.

---

Quick Install

# 1. Install uv (if needed)
# curl -LsSf https://astral.sh/uv/install.sh | sh
uv tool install cicada-mcp

# In your repo 
cicada claude   # or: cicada cursor, cicada vs, cicada gemini, cicada codex, cicada opencode

Try before installing permanently

uvx --from cicada-mcp cicada claude   # or cursor, vs

Runs CICADA on demand (worse indexing quality, but zero install).

Available commands after installation:

• cicada [claude|cursor|vs|gemini|codex|opencode] - One-command setup per project
• cicada-mcp - MCP server (auto-started by editor)
• cicada watch - Watch for file changes and automatically reindex
• cicada index - Re-index code with custom options (-f/--force + --fast/--regular/--max, --watch)
• cicada index-pr - Index pull requests for PR attribution
• cicada find-dead-code - Find potentially unused functions

Ask your assistant:

"Show me the functions in MyApp.User"
"Where is authenticate/2 called?"
"Find code related to API authentication"

---

Privacy & Security

• 100% local: parsing + indexing happen on your machine; no cloud uploads.
• No telemetry: CICADA doesn't collect usage or phone home.
• Read-only tools: MCP endpoints only read the index; they can't change your repo.
• Optional GitHub access: PR features rely on gh and your existing OAuth token.
• Data layout:

  ~/.cicada/projects/<repo_hash>/
  ├─ index.json      # modules, functions, call sites, metadata
  ├─ config.yaml     # indexing options + keyword tier
  ├─ hashes.json     # incremental indexing cache
  └─ pr_index.json   # optional PR metadata + reviews
  

  Your repo only gains an editor config (.mcp.json, .cursor/mcp.json, .vscode/settings.json, .gemini/mcp.json, .codex/mcp.json, or .opencode.json).

---

For Developers

Wire CICADA into your editor once, and every assistant session inherits the context.

Install & Configure

cd /path/to/project
cicada claude   # or cicada cursor / cicada vs / cicada gemini / cicada codex / cicada opencode

Enable PR Attribution (optional)

brew install gh    # or apt install gh
gh auth login
cicada index-pr .     # incremental
cicada index-pr . --clean   # full rebuild

Unlocks questions like "Which PR introduced line 42?" or "What did reviewers say about billing.ex?"

Automatic Re-indexing with Watch Mode

Enable automatic reindexing when files change by starting the MCP server with the --watch flag:

** .mcp.json**

{
  "mcpServers": {
    "cicada": {
      "command": "cicada-mcp",
      "args": ["--watch"],
      "env": {
        "CICADA_CONFIG_DIR": "/home/user/.cicada/projects/<hash>"
      }
    }
  }
}

When watch mode is enabled:

• A separate process monitors .ex and .exs files for changes
• Changes are automatically reindexed (incremental, fast)
• 2-second debounce prevents excessive reindexing during rapid edits
• The watch process stops automatically when the MCP server stops
• Excluded directories: deps, _build, node_modules, .git, assets, priv

CLI Cheat Sheet

Command	Purpose	Run When
cicada claude	Configure MCP + incremental re-index	First setup, after local changes
cicada watch	Monitor files and auto-reindex on changes	During active development
cicada index --force --regular .	Full rebuild w/ semantic keywords	After large refactors or enabling AI tier
cicada index-pr .	Sync PR metadata/reviews	After new PRs merge
cicada find-dead-code --min-confidence high	List unused public functions	Cleanup sprints

Troubleshooting

"Index file not found"

Run the indexer first:

cicada index /path/to/project

Ensure indexing completed successfully. Check for ~/.cicada/projects/<hash>/index.json.

"Module not found"

Use the exact module name as it appears in code (e.g., MyApp.User, not User).

If module was recently added, re-index:

cicada index .

MCP Server Won't Connect

Troubleshooting checklist:

1. Verify configuration file exists:

   # For Claude Code
   ls -la .mcp.json
   
   # For Cursor
   ls -la .cursor/mcp.json
   
   # For VS Code
   ls -la .vscode/settings.json
   

2. Check paths are absolute:

   cat .mcp.json
   # Should contain: /absolute/path/to/project
   # Not: ./project or ../project
   

3. Ensure index exists:

   ls -la ~/.cicada/projects/
   # Should show directory for your project
   

4. Restart editor completely (not just reload window)

5. Check editor MCP logs:

   • Claude Code: --debug
   • Cursor: Settings → MCP → View Logs
   • VS Code: Output panel → MCP

PR Features Not Working

Setup GitHub CLI:

# Install GitHub CLI
brew install gh  # macOS
sudo apt install gh  # Ubuntu
# or visit https://cli.github.com/

# Authenticate
gh auth login

# Index PRs
cicada index-pr

Common issues:

• "No PR index found" → Run cicada index-pr .
• "Not a GitHub repository" → Ensure repo has GitHub remote
• Slow indexing → First-time indexing fetches all PRs; subsequent runs are incremental
• Rate limiting → GitHub API has rate limits; wait and retry if you hit limits

Force rebuild:

cicada index-pr --clean

Keyword Search Not Working

Error: "Keyword search not available"

Cause: Index was built without keyword extraction.

Solution:

# Re-index with keyword extraction
cicada index .  # or --fast or --max

Verify:

cat ~/.cicada/projects/<hash>/config.yaml
# Should show keyword_extraction: enabled

More detail: docs/PR_INDEXING.md, docs/08-INCREMENTAL_INDEXING.md.

---

For AI Assistants

CICADA ships 7 focused MCP tools designed for efficient code exploration.

🧭 Which Tool Should You Use?

Need	Tool	Notes
Start exploring	query	🚀 START HERE - Smart discovery with keywords/patterns + filters (scope, recent, path)
View a module's complete API	search_module	Functions, signatures, specs, docs. Use what_calls_it/what_it_calls for bidirectional analysis
Find where a function is used	search_function	Definition + all call sites. Supports wildcards (*) and OR (|) patterns
Track git history	git_history	Unified tool: blame, commits, PRs, function evolution (replaces 4 legacy tools)
Find dead code	find_dead_code	Identify potentially unused functions with confidence levels
Drill down into results	expand_result	Auto-expands modules or functions from query results
Advanced index queries	query_jq	Custom jq queries for power users

Want to see these tools in action? Check out Complete Workflow Examples with pro tips and real-world scenarios.

Core Tools

query - Smart code discovery (your starting point)

• Automatically detects keywords vs patterns
• Filters: scope (public/private), recent (last 14 days), filter_type (modules/functions), match_source (docs/strings)
• Returns snippets with smart next-step suggestions
• Use path_pattern to filter by location

search_module - Deep module analysis

• View complete API: functions, signatures, specs, docs
• Bidirectional analysis:
  • what_calls_it=true → See who uses this module (impact analysis)
  • what_it_calls=true → See what this module depends on
• Supports wildcards (MyApp.*) and OR patterns (MyApp.User|MyApp.Post)
• Filter by visibility (public/private/all)

search_function - Function usage tracking

• Find definitions and all call sites
• what_calls_it=true (default) → See all callers
• what_it_calls=true → See all dependencies
• Include code examples with include_usage_examples=true
• Filter by usage_type: source, tests, or all

Git History (Unified Tool)

git_history - All git operations in one tool

• Single line: git_history("file.ex", start_line=42) → blame + PR
• Line range: git_history("file.ex", start_line=40, end_line=60) → grouped blame
• Function tracking: git_history("file.ex", function_name="create_user") → evolution
• File history: git_history("file.ex") → all PRs/commits
• Time filtering: recent=true (14d), recent=false (>14d), recent=null (all)
• Author filtering: author="john"
• Automatic PR index integration when available

Additional Tools

expand_result - Drill down from query results

• Auto-detects module vs function
• Shows complete details with usage examples
• Configure what to include: code, dependencies, callers
• Convenient wrapper around search_module and search_function

find_dead_code - Code cleanup analysis

• Three confidence levels (high, medium, low)
• Smart detection of callbacks and behaviors
• Recognition of dynamic call patterns
• Module-level grouping with line numbers
• Excludes test files and @impl functions

query_jq - Advanced index queries

• Direct jq queries against the index
• Schema discovery with | schema
• Compact (default) or pretty output
• Sample mode for large results

Detailed parameters + output formats: MCP_TOOLS_REFERENCE.md.

Token-Friendly Responses

All tools return structured Markdown/JSON snippets (signatures, call sites, PR metadata) instead of full files, keeping prompts lean.

---

---

Documentation

• docs/17-WORKFLOW_EXAMPLES.md
• docs/12-TOOL_DISCOVERABILITY_TASKS.md.
• CHANGELOG.md – release notes.
• docs/01-KEYWORD_EXTRACTION_ANALYSIS.md – semantic search internals.
• docs/09-PR_INDEXING.md – GitHub integration details.
• docs/16-MCP_TOOL_CALL_BENCHMARKING.md – token/time benchmarks.

---

Roadmap

PYTHON AND TYPESCRIPT!!!

---

Contributing

git clone https://github.com/wende/cicada.git
cd cicada
uv sync
pytest

Before submitting a PR:

• Run black cicada tests
• Ensure tests + coverage pass (pytest --cov=cicada --cov-report=term-missing)
• Update docs if behaviour changes

We welcome issues/PRs for:

• New language grammars
• Tool output improvements
• Better onboarding docs and tutorials

---

License

MIT – see LICENSE.

Stop letting your AI search blindly. Give it CICADA.

Get Started · Report Issues