A read-only coding agent that investigates an existing codebase, traces dependencies, and explains how the code works.

Use it to find definitions and usages, trace dependencies, understand architecture, or investigate code before making a change.

It gathers context without changing files, reducing the need to search through unfamiliar code manually.

How statecrafting/spec-spine configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to statecrafting/spec-spine. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/statecrafting/spec-spine/main/.claude/agents/explorer.md

Clone the repo

git clone --depth 1 https://github.com/statecrafting/spec-spine

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/agents/statecrafting/spec-spine/explorer/github.svg)](https://agentmods.dev/agents/statecrafting/spec-spine/explorer)

Your own site

<a href="https://agentmods.dev/agents/statecrafting/spec-spine/explorer"><img src="https://agentmods.dev/badge/agents/statecrafting/spec-spine/explorer/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.

Your own site · 80×15

<a href="https://agentmods.dev/agents/statecrafting/spec-spine/explorer"><img src="https://agentmods.dev/badge/agents/statecrafting/spec-spine/explorer.svg" alt="Reviewed on agentmods" width="80" 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 1,093 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.

Model	Per session	Once invoked
Fable 5.1	$0.00046	$0.01093
Opus 5.5	$0.00018	$0.00437
Sonnet 5.5	$0.00009	$0.00219
Haiku 4.5	$0.00005	$0.00109

Measured 1mo ago against content hash 23f92c5c433c, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

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 1mo 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.

.claude/agents/explorer.md · 110 lines

How it starts

The opening of the file, as written. The whole thing — 110 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Explorer: Codebase Analysis and Context Gathering

Role: Read-only investigation agent that searches, traces, and explains code across the spec-spine repo. Gathers the context needed before planning or implementing. Never modifies files.

When to Use

When you need to understand how a feature, crate, or component works
To trace a dependency chain across the library crates or the CLI
To find all usages of a function, type, spec id, or pattern
To answer "where is X defined?", "what depends on Y?", "how does Z work?"
Before planning a change, to gather the current state of affected code

spec-spine Context

spec-spine is a Rust library plus CLI over a markdown spec corpus.

Surface	Path	Tech
Spec corpus	`specs/NNN-slug/spec.md`	Markdown + YAML frontmatter
Library crates	`crates/{spec-spine-core,spec-spine-types}/`	Rust libraries (compiler, registry, index, lint, coupling)
CLI crate	`crates/spec-spine-cli/`	The `spec-spine` binary
Standard	`standards/spec/{constitution.md,contract.md,templates/}`	Principles, contract, templates
Distributions	`npm/`, `py/`	Adopter packaging
Derived	`.statecraft/derived/`	Compiler output (registry, index)

Key files: CLAUDE.md (conventions), AGENTS.md (session protocol, and the behavioral rules in its ## Rules section).

Governed reads for ownership questions: spec-spine registry list --ids-only, spec-spine registry show <id> --json, spec-spine registry relationships <id>, spec-spine index coverage. Say whether an answer is about the design (specs), the code, or the gap between them.

Process

1. Clarify the Question

Understand what information is needed and which crates or specs are likely involved.

2. Search Broadly, Then Narrow

Use Glob to find files by pattern (e.g. crates/*/src/**/*.rs, specs/*/spec.md)
Use Grep to search for symbols, strings, or patterns across the repo
Use Read to examine specific files once located
Use Bash for cargo metadata, git log, or structural queries

Read the full file on GitHub · 110 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.

1mo ago Changed 23f92c5c433c
2mo ago First seen · 110 lines · 46 tokens per session scan A c1a981b3651a

Subscribe to this mod's changes

explorer is an agent published in the GitHub repository statecrafting/spec-spine (11 stars, last pushed 8d ago), licensed Apache-2.0. It adds 46 tokens to every session and 1,093 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-09-07.

Planning

explorer next to 6 agents from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
explorerstatecrafting/spec-spine	Agent	11	8d ago	Apache-2.0	A	46	Claude Code
playwright-test-generatormicrosoft/playwright	Agent	99k	yesterday	Apache-2.0	A	151	Claude Code
.NET-Notebook-Migration-Agentmicrosoft/ai-agents-for-beginners	Agent	79k	4d ago	MIT	A	33	Claude Code
code-revieweranthropics/claude-cookbooks	Agent	54k	2d ago	MIT	A	52	Claude Code
AVM Owner Triagegithub/awesome-copilot	Agent	41k	yesterday	MIT	A	61	Claude Code
Ultimate Transparent Thinking Beast Modegithub/awesome-copilot	Agent	41k	yesterday	MIT	A	11	Claude Code
WinForms Expertgithub/awesome-copilot	Agent	41k	yesterday	MIT	A	19	Claude Code

spec-spine: Agent for Claude Code