agentic-development

agentic-development is a skill for Claude Code from alinaqi/maggy. It costs 22 tokens per session (5,657 once invoked), scanned A, original, MIT.

A development guide for building AI agents in Python with Pydantic AI or in Node.js with the Claude Agent SDK. AI agents are programs that perform multi-step tasks using instructions and tools.

In plain words
What is it for?
Use it to build autonomous agents, define validated results, add tools, and choose an approach for Python, Node.js, or Next.js projects.
Why use it?
It helps choose a framework and set up agents that can use several models, tools, and structured results.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter. Also seen: mentions Claude Code.

Good fit Use it to build autonomous agents, define validated results, add tools, and choose an approach for Python, Node.js, or Next.js projects.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/alinaqi/maggy/agentic-development
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.

Any agent
npx skills add alinaqi/maggy --skill agentic-development
Clone the repo
git clone --depth 1 https://github.com/alinaqi/maggy

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.

agentmods badge for agentic-development

README.md
[![agentmods](https://agentmods.dev/badge/skills/alinaqi/maggy/agentic-development/github.svg)](https://agentmods.dev/skills/alinaqi/maggy/agentic-development)
Your own site
<a href="https://agentmods.dev/skills/alinaqi/maggy/agentic-development"><img src="https://agentmods.dev/badge/skills/alinaqi/maggy/agentic-development/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 agentic-development

Your own site · 80×15
<a href="https://agentmods.dev/skills/alinaqi/maggy/agentic-development"><img src="https://agentmods.dev/badge/skills/alinaqi/maggy/agentic-development.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 22 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,657 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. Third-party audits
  • Socket pass 14 Jul 2026
  • Snyk warn 14 Jul 2026
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 3 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Memory Poisoning · line 108
    Skill manipulates agent memory, state, or stored context. Memory corruption can alter personality, override safety rules, or cause unpredictable behavior.
    Fix: Protect agent memory and state from modification by untrusted content. Use read-only memory for critical instructions and validate all state changes.
  • medium Data Exfiltration · line 638
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium Excessive Agency · line 817
    Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.
    Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
How audits are shown
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 $0.00022 $0.05657
Opus 5.5 $0.00009 $0.02263
Sonnet 5.5 $0.00004 $0.01131
Haiku 4.5 $0.00002 $0.00566

Measured 1mo ago against content hash 04c0b8b91c12, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

agentic-development 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.

skills/agentic-development/SKILL.md · 856 lines

How it starts

The opening of the file, as written. The whole thing — 856 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agentic Development Skill

For building autonomous AI agents that perform multi-step tasks with tools.

Sources: Claude Agent SDK | Anthropic Claude Code Best Practices | Pydantic AI | Google Gemini Agent Development | OpenAI Building Agents


Framework Selection by Language

Language/Framework Default Why
Python Pydantic AI Type-safe, Pydantic validation, multi-model, production-ready
Node.js / Next.js Claude Agent SDK Official Anthropic SDK, tools, multi-agent, native streaming

Python: Pydantic AI (Default)

from pydantic_ai import Agent
from pydantic import BaseModel

class SearchResult(BaseModel):
    title: str
    url: str
    summary: str

agent = Agent(
    'claude-sonnet-4-6',
    result_type=list[SearchResult],
    system_prompt='You are a research assistant.',
)

# Type-safe result
result = await agent.run('Find articles about AI agents')
for item in result.data:
    print(f"{item.title}: {item.url}")

Node.js / Next.js: Claude Agent SDK (Default)

import Anthropic from "@anthropic-ai/sdk";

const client = new Anthropic();

// Define tools
const tools: Anthropic.Tool[] = [
  {
    name: "web_search",
    description: "Search the web for information",
    input_schema: {
      type: "object",
      properties: {
        query: { type: "string", description: "Search query" },
      },
      required: ["query"],
    },
  },
];

// Agentic loop
async function runAgent(prompt: string) {
  const messages: Anthropic.MessageParam[] = [
    { role: "user", content: prompt },
  ];

  while (true) {
    const response = await client.messages.create({
      model: "claude-sonnet-4-6",
      max_tokens: 4096,
      tools,
      messages,
    });

    // Check for tool use
    if (response.stop_reason === "tool_use") {
      const toolUse = response.content.find((b) => b.type === "tool_use");
      if (toolUse) {
        const result = await executeTool(toolUse.name, toolUse.input);
        messages.push({ role: "assistant", content: response.content });
        messages.push({
          role: "user",
          content: [{ type: "tool_result", tool_use_id: toolUse.id, content: result }],
        });
        continue;
      }
    }

    // Done - return final response
    return response.content.find((b) => b.type === "text")?.text;
  }
}

Read the full file on GitHub · 856 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. 1mo ago Changed 04c0b8b91c12
  2. 1mo ago First seen · 856 lines · 22 tokens per session scan A a2e10dd2aabb

Subscribe to this mod's changes

agentic-development is a skill published in the GitHub repository alinaqi/maggy (710 stars, last pushed 7d ago), licensed MIT. It adds 22 tokens to every session and 5,657 once invoked, about $0.0001 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 2026-08-30.

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