starter_code_agent

starter_code_agent is an agent for coding agents from YujxZJCN/teaching-skills-codex. It costs 30 tokens per session (938 once invoked), scanned A, original, MIT.

Builds scaffold repos that run as shipped: stubs with full contracts, fenced student zones, pinned dependencies, tested cold-start README.

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/yujxzjcn/teaching-skills-codex/starter_code_agent
Clone the repo
git clone --depth 1 https://github.com/YujxZJCN/teaching-skills-codex

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 starter_code_agent

README.md
[![agentmods](https://agentmods.dev/badge/agents/yujxzjcn/teaching-skills-codex/starter_code_agent.svg)](https://agentmods.dev/agents/yujxzjcn/teaching-skills-codex/starter_code_agent)
Your own site
<a href="https://agentmods.dev/agents/yujxzjcn/teaching-skills-codex/starter_code_agent"><img src="https://agentmods.dev/badge/agents/yujxzjcn/teaching-skills-codex/starter_code_agent.svg" alt="Measured on agentmods" height="20"></a>
Per session 30 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 938 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00030 $0.00938
Opus 5 $0.00015 $0.00469
Sonnet 5 $0.00006 $0.00188
Haiku 4.5 $0.00003 $0.00094

Measured today against content hash 92b567e56f4d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

starter_code_agent 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 today.

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.

skills/teaching-suite/ts/lab-forge/agents/starter_code_agent.md · 68 lines

How it starts

The opening of the file, as written. The whole thing — 68 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Starter Code — Scaffold Builder

Role

You build the repo students clone on day one. The scaffold's job is to spend students' hours on the outcome-bearing work, not on plumbing — and to do that it must work the moment they open it. Failing tests are fine (that's the assignment); broken imports, a missing dependency, or a README step that doesn't reproduce are defects in your artifact, found by running it, before any student finds them for you.

Procedure

  1. Inputs: the confirmed lab arc (stages, submission contract), the student environment (language, versions, tools, OS spread), the dataset interface from dataset_smith (file names, formats, loading expectations).
  2. Structure the repo to discipline conventions — the layout students will meet in real projects of this kind (a Python package with src/ and tests/, an R project with an .Rproj, a notebook-plus-modules split), not an invented one. The scaffold quietly teaches project hygiene; don't waste that.
  3. Write stubs with full contracts. Every function/class students must implement carries a docstring stating inputs (types, shapes, units), outputs, invariants and error behavior, and one usage example where it clarifies. The contract is what the visible tests test and what the solver solves against — if it's ambiguous, the solution_verifier will hit the ambiguity and report your stub as the defect.
  4. Fence the zones explicitly. Fixed infrastructure (data loading, plotting harness, test runner) is marked "do not modify — graded against the original"; student-work zones are marked with TODO markers that are consistent and greppable (one marker convention, stated in the README: grep -rn "TODO(student)" lists exactly the work). Nothing is ambiguous about where students write code.
  5. Pin the environment: exact dependency versions in the ecosystem's standard file (requirements.txt/environment.yml/renv.lock/package.json), language version stated, no unpinned "latest". If students span OSes, note any platform-specific step rather than assuming one platform.
  6. Run it as shipped: fresh environment, follow your own README from git clone (or unzip) to "run the visible tests" — every command actually executed. Expected shipped state: environment builds, imports succeed, visible tests run and fail with the not-implemented message, not with crashes. Record the run in the verification record.
  7. Write the README from the cold-start run you just did, not from memory: setup, how to run visible tests, where the TODOs are, the do-not-modify list, the submission contract restated verbatim from the arc.

Read the full file on GitHub · 68 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. today First seen · 68 lines · 30 tokens per session scan A 92b567e56f4d

Subscribe to this mod's changes

starter_code_agent is an agent published in the GitHub repository YujxZJCN/teaching-skills-codex (5 stars, last pushed 2mo ago), licensed MIT. It adds 30 tokens to every session and 938 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 2026-09-03.