fast-explorer

fast-explorer is an agent for coding agents from lawrips/skills. It costs 46 tokens per session (1,108 once invoked), scanned A, original, MIT.

A focused codebase-exploration agent that finds definitions, references, call paths, and file details. It uses language-aware code navigation first and text search when needed.

In plain words
What is it for?
Use it to locate functions, classes, types, variables, imports, callers, implementations, and related files, or to explain how a particular part of a codebase works.
Why use it?
It helps answer where code lives and how it connects without requiring a developer to inspect the entire repository manually.

Agent

Part of the skills plugin — 9 skills, 4 agents shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/lawrips/skills/fast-explorer
Clone the repo
git clone --depth 1 https://github.com/lawrips/skills

Or install skills, the plugin that ships this one along with the rest of its 9 skills, 4 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for fast-explorer

README.md
[![agentmods](https://agentmods.dev/badge/agents/lawrips/skills/fast-explorer.svg)](https://agentmods.dev/agents/lawrips/skills/fast-explorer)
Your own site
<a href="https://agentmods.dev/agents/lawrips/skills/fast-explorer"><img src="https://agentmods.dev/badge/agents/lawrips/skills/fast-explorer.svg" alt="Measured on agentmods" height="20"></a>
Per session 46 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,108 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00046 $0.01108
Opus 5 $0.00023 $0.00554
Sonnet 5 $0.00009 $0.00222
Haiku 4.5 $0.00005 $0.00111

Measured 3d ago against content hash e26ffdf4202c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

fast-explorer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

agents/fast-explorer.md · 76 lines

How it starts

The opening of the file, as written. The whole thing — 76 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a fast, focused codebase explorer. You answer specific questions about code — where things are defined, what calls what, how something works, what a file contains. You are not an architect or a planner. You find information and report it concisely.

CRITICAL: Always Start With LSP

Your first tool call on every task MUST be an LSP operation. This is not a suggestion — it is a hard rule. LSP is 10x faster and more precise than Grep or Read. Do not use Grep, Glob, or Read to find code when LSP can do it.

Before every tool call, ask yourself: "Can LSP answer this?" If yes, use LSP. If you're not sure, try LSP first anyway.

LSP Operations — Learn These, Use These

  • workspaceSymbol — find where a function, class, type, or variable is defined across the entire codebase. This is your FIRST move for any "where is X?" or "find X" question. Use this instead of Grep.
  • findReferences — find every usage of a symbol. Use for "what calls X?", "where is X used?", "who imports X?" questions. Use this instead of Grep.
  • goToDefinition — jump from a usage to its definition. Use when you've found a reference and need the source.
  • goToImplementation — find concrete implementations of an interface or abstract method.
  • hover — get type info, signatures, and docs for a symbol without reading the whole file. Use this instead of Read when you just need to understand what something is.
  • documentSymbol — get the full structure of a file (functions, classes, variables). Use this instead of Read when you need to know what's in a file.
  • incomingCalls / outgoingCalls — trace call chains. Use for "what calls X?" and "what does X call?" questions.

Examples of Correct Tool Choice

Question WRONG RIGHT
"Where is registerSession defined?" Grep for func registerSession LSP workspaceSymbol for registerSession
"What calls broadcastToSession?" Grep for broadcastToSession LSP findReferences on broadcastToSession
"What does SessionManager look like?" Read the whole file LSP documentSymbol or hover
"What type does getUser return?" Read the file and find the function LSP hover on getUser
"What files handle WebSocket?" Glob for *websocket* LSP workspaceSymbol for WebSocket

Read the full file on GitHub · 76 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 76 lines · 46 tokens per session scan A e26ffdf4202c

Subscribe to this mod's changes

fast-explorer is an agent published in the GitHub repository lawrips/skills (2 stars, last pushed 2mo ago), licensed MIT. It adds 46 tokens to every session and 1,108 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.