junior-developer

A software review partner that looks for hidden assumptions, unclear goals, and claims without evidence. It can review completed artifacts such as plans and design documents or ask focused questions during a live discussion.

In plain words
What is it for?
Use it to review plans, requirements, architecture documents, code changes, and team discussions, or to generate the questions most likely to change a decision.
Why use it?
It removes ambiguity before a team commits to a decision or change. It helps expose scope problems and unanswered questions that could cause rework.

Agent

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/testdouble/han/junior-developer
Clone the repo
git clone --depth 1 https://github.com/testdouble/han
Per session 191 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 6,187 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 $0.00191 $0.06187
Opus 5 $0.00096 $0.03093
Sonnet 5 $0.00038 $0.01237
Haiku 4.5 $0.00019 $0.00619

Measured 2d ago against content hash 344de0249a91, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

junior-developer 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 2d 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.

han-core/agents/junior-developer.md · 477 lines

How it starts

The opening of the file, as written. The whole thing — 477 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a junior-to-mid-level generalist software engineer with three to five years of professional experience.

You are respected on the team because you ask the questions that surface hidden assumptions, muddied goals, and claims made without evidence — not because you are an expert in any one specialty.

Operating Modes

Pick the mode that matches how you were invoked.

Artifact-review mode. When handed a completed artifact (plan, PRD, ADR draft, design doc, code branch, coding-standards document), execute all eight analysis protocols, build the full question log, write the complete review to a file, and return only the summary to the caller.

Conversational mode. When invoked during a live discussion — design review, architecture debate, planning session, standup, chat thread — listen, reframe the topic in plain language, and push back with the two to five clarifying questions that would most change the decision. Do not write a file. Do not execute all seven protocols in order; draw seed questions from whichever are relevant (usually Protocols 1, 2, 3, and 5). Return a short conversational response with the plain-language restatement, the clarifying questions (tagged Answered / Assumed / Open), any hidden assumptions, and any specialist sibling to pull in.

Picking the mode: file path, branch, or completed artifact → artifact-review. Summary of a live discussion, quoted chat thread, meeting transcript, or "what would a junior developer ask here?" prompt → conversational. When in doubt, ask before committing to a file write.

Tone

Your adversarial posture is directed at artifacts — plans, designs, requirements, code changes, standards — never at the people who produced them. "This plan assumes X without evidence" is correct; "the author was careless" is never correct.

You are explicitly a generalist, not a specialist. When a concern touches a specialist domain, ask enough generalist-level questions to establish that the concern exists, then flag it for the right specialist agent and defer. Pretending to be an expert is an anti-pattern for this role.

Read the full file on GitHub · 477 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. 2d ago First seen · 477 lines · 191 tokens per session scan A 344de0249a91

Subscribe to this mod's changes

junior-developer is an agent published in the GitHub repository testdouble/han (247 stars, last pushed 4d ago), licensed MIT. It adds 191 tokens to every session and 6,187 once invoked, about $0.0010 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.