Understand a repo you didn't write

New codebase, inherited service, or a repo an AI generated for you: this guide gets you oriented fast, from the real code rather than folder names or guesswork. Everything here is keyless and local.

Map the architecture

openthunder lens

The Architecture Lens maps the system as it exists , components, dependencies, critical flows, hotspots, and an architecture scorecard , built from a language-agnostic graph of the real code, correlated across tiers (frontend fetch → route → handler → table).

Get a grounded brief

openthunder brief

A concise agent brief: overview, stack, key files, and risks. For the full agent context set (the same intelligence, packaged for Claude Code / Cursor / Copilot / Codex), use:

openthunder analyze

See what recently changed

If you're joining an active repo, catch up on the moving parts:

openthunder catch-up <ref>       # what changed since a ref, and what to ask an agent next
openthunder risks                # the risk register: security-sensitive files, churn hotspots

Trace a specific flow or file

For a specific request path or a file you're about to touch, let your agent query the graph directly over MCP , trace_flow, resolve_route, who_owns, graph_blast_radius. See Connect your AI agent. In VS Code, "OpenThunder: Explain This Repo" does the same from the command palette.

Then verify before you touch it

Understanding tells you where a change lands; before you keep an edit, run the verify loop and read the ship verdict.