lsp-understand

Requires the agent-lsp MCP server.

lsp-understand

Deep-dive exploration of unfamiliar code — given a symbol or file, synthesizes hover info, implementations, call hierarchy (bounded to 2 levels), all references, and source into a structured Code Map.

Read-only — does not modify any files.

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Differentiation from lsp-explore

/lsp-explore is a single-symbol pass: given one symbol name, it runs hover + implementations + call hierarchy + references and produces a per-symbol report. Use lsp-explore for quick "what is this one thing" questions.

/lsp-understand is broader in three ways:

1. Accepts a file path as input — explores all exported symbols in that file as a group (Mode B), rather than requiring a single symbol name.
2. Synthesizes cross-symbol relationships — produces a dependency map showing how entry points call each other, share callers, or implement the same interface, rather than isolated per-symbol reports.
3. Enforces a 2-level call hierarchy depth limit — prevents infinite recursion in deeply connected code.

Use lsp-understand for "how does this module work as a whole."

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Input — Two Modes

Mode A (symbol): User provides a symbol name in dot notation (e.g., "codec.Encode", "Handler.ServeHTTP").

Mode B (file): User provides an absolute file path. All exported symbols in the file become the entry points.

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Prerequisites

Call mcp__lsp__get_server_capabilities before Step 2 to determine which capabilities are available. Skip steps that require missing capabilities:

• go_to_implementation: skip Step 2b if implementationProvider: false
• find_callers: skip Steps 2c and 2d if callHierarchyProvider: false; note in the Code Map output that call hierarchy was unavailable

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Step 1 — Entry Point Resolution

Mode A: Single Symbol

Call mcp__lsp__go_to_symbol to locate the symbol definition:

mcp__lsp__go_to_symbol({
  "symbol_path": "<dot-notation name>",   // e.g. "codec.Encode"
  "workspace_root": "<root>"              // optional
})
→ returns: file_path, line, column (1-indexed)