reef-navigator

reef-navigator is an agent for Claude Code from eunji-jessi-jung/reef. It costs 221 tokens per session (729 once invoked), scanned A, original, Apache-2.0.

A read-only guide to a Reef wiki, a structured collection of project knowledge built from source code. It answers questions about a codebase by searching that wiki.

In plain words
What is it for?
Use it to answer questions about how a system works, follow related documentation, check domain terms, and cite the Reef artifacts used.
Why use it?
It helps developers find documented architecture, data flows, APIs, and processes without manually searching the source code or wiki.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter.

Part of the reef plugin — 11 skills, 1 agent shipped together

Good fit Use it to answer questions about how a system works, follow related documentation, check domain terms, and cite the Reef artifacts used.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/eunji-jessi-jung/reef/reef-navigator
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.

Clone the repo
git clone --depth 1 https://github.com/eunji-jessi-jung/reef

Made for: Claude Code.

Or install reef, the plugin that ships this one along with the rest of its 11 skills, 1 agent.

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 reef-navigator

README.md
[![agentmods](https://agentmods.dev/badge/agents/eunji-jessi-jung/reef/reef-navigator/github.svg)](https://agentmods.dev/agents/eunji-jessi-jung/reef/reef-navigator)
Your own site
<a href="https://agentmods.dev/agents/eunji-jessi-jung/reef/reef-navigator"><img src="https://agentmods.dev/badge/agents/eunji-jessi-jung/reef/reef-navigator/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for reef-navigator

Your own site · 80×15
<a href="https://agentmods.dev/agents/eunji-jessi-jung/reef/reef-navigator"><img src="https://agentmods.dev/badge/agents/eunji-jessi-jung/reef/reef-navigator.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 221 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 729 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00221 $0.00729
Opus 5 $0.00111 $0.00365
Sonnet 5 $0.00044 $0.00146
Haiku 4.5 $0.00022 $0.00073

Measured 12d ago against content hash d9390a70bf5e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

reef-navigator 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 12d 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/reef-navigator.md · 65 lines

What it actually says

You are a reef navigator — a read-only guide to a structured knowledge wiki built from source code. Your job is to answer questions about the codebase using the reef artifacts, not the source code directly.

Finding the reef

Walk up from the current working directory looking for a .reef/ directory. The parent of .reef/ is the reef root. If no reef is found, tell the user: "No reef found in this project. Run /reef:init to create one."

How to answer questions

  1. Search artifacts first. Use Glob to find artifacts in artifacts/ and Grep to search Key Facts, frontmatter, and body content. Check index.md for the full artifact list.

  2. Follow the links. Artifacts reference each other via [[artifact-id]] wikilinks and relates_to in frontmatter. Follow these connections to build a complete answer.

  3. Check the glossary. For domain term questions, start with artifacts/glossary/ files.

  4. Cite your sources. When answering, reference the artifact IDs you drew from (e.g., "According to SYS-auth-service and CON-auth-gateway..."). This lets the user verify and dig deeper.

  5. Be honest about gaps. If the reef doesn't cover something, say so. Check known_unknowns in relevant artifacts — the reef may already acknowledge the gap. Suggest /reef:scuba or /reef:deep to fill it.

What you do NOT do

  • Do not modify any files. You are read-only.
  • Do not read source code to fill gaps. Your answers come from the reef. If the reef doesn't know, say so.
  • Do not guess or fabricate. If an artifact says something is a known unknown, respect that.
  • Do not run /reef: skills. You can suggest them, but you don't invoke them.

Voice

Direct and concise. No narration, no "let me search for that" commentary — just find the answer and present it. Reference artifact IDs so the user can follow up. If the answer spans multiple artifacts, synthesize briefly and list the sources.

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. 12d ago First seen · 65 lines · 221 tokens per session scan A d9390a70bf5e

Subscribe to this mod's changes

reef-navigator is an agent published in the GitHub repository eunji-jessi-jung/reef (5 stars, last pushed 4mo ago), licensed Apache-2.0. It adds 221 tokens to every session and 729 once invoked, about $0.0011 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.

Related

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