deep-reasoner

deep-reasoner is an agent for Claude Code from AndyShaman/senior-fable. It costs 66 tokens per session (291 once invoked), scanned A, original, MIT.

An agent for long, context-heavy investigations across code, logs, and background material.

In plain words
What is it for?
Use it for broad codebase exploration, multi-file debugging, log analysis, and research that needs more context than a quick lookup.
Why use it?
It keeps messy research out of the main conversation and returns a short conclusion with evidence, ruled-out possibilities, and open questions.

Agent for Claude Code

Written for Claude Code: effort in frontmatter. Also seen: model in frontmatter; names the NotebookEdit tool.

Part of the senior-fable plugin — 1 skill, 4 agents shipped together

Good fit Use it for broad codebase exploration, multi-file debugging, log analysis, and research that needs more context than a quick lookup.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/andyshaman/senior-fable/deep-reasoner
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/AndyShaman/senior-fable

Made for: Claude Code.

Or install senior-fable, the plugin that ships this one along with the rest of its 1 skill, 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 deep-reasoner

README.md
[![agentmods](https://agentmods.dev/badge/agents/andyshaman/senior-fable/deep-reasoner.svg)](https://agentmods.dev/agents/andyshaman/senior-fable/deep-reasoner)
Your own site
<a href="https://agentmods.dev/agents/andyshaman/senior-fable/deep-reasoner"><img src="https://agentmods.dev/badge/agents/andyshaman/senior-fable/deep-reasoner.svg" alt="Measured on agentmods" height="20"></a>
Per session 66 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 291 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 $0.00066 $0.00291
Opus 5 $0.00033 $0.00146
Sonnet 5 $0.00013 $0.00058
Haiku 4.5 $0.00007 $0.00029

Measured 4d ago against content hash 8d145eb5e3e6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

deep-reasoner 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 4d 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/deep-reasoner.md · 24 lines

What it actually says

You are a research engineer. You take on long, messy investigations so the orchestrating session doesn't have to hold the mess in its context.

Work exhaustively inside your own context: read as many files, logs and sources as the task needs. But your final message is the only thing that comes back — make it a distilled conclusion, not a dump.

Structure your final report as:

  • Answer — the conclusion in 1-3 sentences.
  • Evidence — key findings with file:line references.
  • Ruled out — what you checked that turned out irrelevant, so the work isn't redone.
  • Open questions — anything you could not resolve, stated explicitly.

If the spec is ambiguous, state the assumption you chose and proceed — do not silently guess without flagging it.

Do not modify files or external state, including through shell commands. Your job is understanding, not changing.

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. 4d ago Changed · +1 lines 8d145eb5e3e6
  2. 8d ago First seen · 23 lines · 66 tokens per session scan A c3e09a31a4be

Subscribe to this mod's changes

deep-reasoner is an agent published in the GitHub repository AndyShaman/senior-fable (26 stars, last pushed 6d ago), licensed MIT. It adds 66 tokens to every session and 291 once invoked, about $0.0003 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 2026-08-30.