codebase-search
Semantic codebase search powered by MorphLLM — an RL-trained subagent that runs ~15-30 internal grep+read operations to answer natural language questions about code. Unlike simple grep, it understands intent and traces cross-file flows.
Requires MORPH_API_KEY environment variable.
When to Use
- Understanding how a feature works across multiple files (e.g., "how does the auth middleware validate tokens?")
- Tracing data flow end-to-end (e.g., "what happens when a user clicks checkout?")
- Exploring unfamiliar codebases where you don't know what to grep for
- Answering architectural questions (e.g., "how is the database layer organized?")
- Debugging cross-file interactions where the connection isn't obvious
When NOT to Use
- Simple keyword or symbol searches (e.g., finding all uses of
handleSubmit) — use Grep - Finding files by name or pattern — use Glob
- Looking up library documentation — use context7
- Questions unrelated to the current codebase
Decision Rule
Can you write the grep pattern yourself? Use Grep — it's faster. Can't write the pattern because the question is conceptual? Use codebase-search.
| Task | Tool |
|------|------|
| Find all imports of AuthService | Grep |
| How does AuthService validate tokens? | codebase-search |
| Find files named *.config.ts | Glob |
| How is the config system structured? | codebase-search |
| Find TODO comments | Grep |
| What's left unfinished in the payment flow? | codebase-search |
Workflow
DO NOT read script source code. Run scripts directly and use --help for usage.
Run a Semantic Search
python3 scripts/codebase-search.py search "<natural language query>" [repo_path]
query— a natural language question about the coderepo_path— path to the repo root (defaults to current directory)
# Search the current repo
python3 scripts/codebase-search.py search "how does the authentication flow work"
# Search a specific repo
python3 scripts/codebase-search.py search "how are database migrations handled" /path/to/repo
# Search including node_modules
python3 scripts/codebase-search.py search "how does the router resolve paths" --search-type node_modules
# Increase timeout for large codebases
python3 scripts/codebase-search.py search "trace the payment processing pipeline" --timeout 180
Run python3 scripts/codebase-search.py --help for full usage.
Example Output
Morph Fast Context subagent performed search on repository:
Relevant context found:
- plugins/ora/agents/ariadne.md:*
- plugins/ora/agents/clio.md:*
- plugins/ora/agents/metis.md:*
Here is the content of files:
<file path="plugins/ora/agents/ariadne.md">
1| ---
2| name: Ariadne
3| description: |
4| Use this agent to explore and understand codebases...
...
35| tools: ["Read", "Glob", "Grep", "LSP", "Bash"]
36| skills:
37| - codebase-search
38| ---
</file>
<file path="plugins/ora/agents/clio.md">
1| ---
2| name: Clio
...
</file>
The output lists relevant files found and their full content. Use these results directly — do not re-search the same files with Grep/Read.
Rules
- Write queries as natural language questions —
"How does the auth middleware validate JWT tokens?"works far better than"auth JWT", because codebase search is an RL-trained agent that plans its own search strategy based on your question. - Be specific about what you want to know —
"What happens when a user submits the settings form?"beats"settings form". The more context you give, the better it can target its internal searches. - Use for understanding, not for finding — If you already know the symbol or keyword, Grep is faster. codebase-search shines when you don't know what to look for.
- Default timeout is 120s — codebase search runs many internal operations. For large codebases, increase with
--timeout 180or higher.