find_similar
Search code by natural-language concept when no identifier is known; matches terms like 'payment processing' to relevant symbols via a semantic vector index.
Instructions
Semantic-only search by natural-language description (e.g. 'payment processing' → ChargeUseCase, BillingService). Uses the HNSW vector index built by vex index --semantic (~7-15ms). Prefer over search when you do not know any concrete identifier and want concept-level matching; prefer search when you have a partial name (search fuses semantic + lexical channels for better recall on identifier-shaped queries).
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| query | Yes | Natural-language description of the concept (not an identifier; use find_symbol for those). | |
| exclude | No | Blacklist results by path glob; wins over include (repeatable) | |
| include | No | Whitelist results by path glob, gitignore syntax (repeatable) | |
| auto_update | No | Auto-update the index if stale, or bootstrap it if missing, before running (default: true) | |
| async_update | No | With auto_update, refresh a stale index in the background instead of waiting for it: results come from the index already on disk and _meta.vex.dev/stale says so (default: false) | |
| project_root | No | Absolute path to the project root (defaults to the MCP working directory) | |
| exclude_tests | No | Drop test files from the results (tests/ dirs, *_test.*, test_*.py, *.spec.ts, __tests__/, tests.rs, ...; same set as tests_for). Composes with include/exclude. Path-based only: Rust unit tests inside a `#[cfg(test)] mod tests` block of a non-test file are not excluded. | |
| no_stale_check | No | Skip the staleness check that runs before each call; assumes the index is fresh. Redundant when `auto_update` is true. |