claude-agent-sdk

A development guide for the Claude Agent SDK, a toolkit for building applications that use conversational AI agents and tools.

In plain words
What is it for?
It is for developing Python or TypeScript agent applications, adding tools and external APIs, using sessions or streaming, and tracking usage.
Why use it?
It provides the patterns and API information needed to build, extend, troubleshoot, host, and monitor those applications.

Skill for Claude CodeCodex

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 skills/emdashcodes/claude-code-plugins/claude-agent-sdk
Any agent
npx skills add emdashcodes/claude-code-plugins --skill claude-agent-sdk
Clone the repo
git clone --depth 1 https://github.com/emdashcodes/claude-code-plugins

Made for: Claude Code, Codex.

Per session 52 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,155 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 $0.00052 $0.02155
Opus 5 $0.00026 $0.01077
Sonnet 5 $0.00010 $0.00431
Haiku 4.5 $0.00005 $0.00215

Measured 2d ago against content hash 12cb5a665f76, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

claude-agent-sdk 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.

plugins/claude-agent-sdk-dev/skills/claude-agent-sdk/SKILL.md · 345 lines

How it starts

The opening of the file, as written. The whole thing — 345 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Claude Agent SDK Development

Overview

This skill provides comprehensive documentation and development guidance for building applications with the Claude Agent SDK. Use this skill when working with Claude Agent SDK based applications, implementing SDK features, or answering questions about SDK capabilities in both Python and TypeScript.

The Claude Agent SDK enables building conversational AI agents with access to tools, multi-turn sessions, streaming, structured outputs, and extensibility through Skills, Plugins, Slash Commands, and Subagents.

When to Use This Skill

Activate this skill when:

  • Building new applications using the Claude Agent SDK
  • Implementing SDK features (sessions, permissions, streaming, structured outputs)
  • Adding extensibility (Skills, Plugins, Slash Commands, Subagents, MCP)
  • Integrating custom tools or external APIs
  • Troubleshooting SDK issues or migration from legacy implementations
  • Answering questions about SDK capabilities, APIs, or best practices
  • Setting up hosting and deployment for SDK applications
  • Implementing cost tracking and usage monitoring

Quick Start

API References

The SDK is available in both Python and TypeScript. For detailed API documentation, reference:

  • Python API: references/agent-sdk_python.md
  • TypeScript API: references/agent-sdk_typescript.md

Getting Started

For SDK overview and core concepts, reference:

  • Overview: references/agent-sdk_overview.md

Core Features

1. Session Management

Sessions enable multi-turn conversations with state persistence. To implement sessions:

Reference: references/agent-sdk_sessions.md

Key concepts:

  • Creating and managing sessions
  • Persisting conversation state
  • Resuming sessions across requests
  • Session lifecycle and cleanup

When to reference: When implementing multi-turn conversations, state persistence, or conversation continuity.

2. Permissions System

The SDK includes a permissions system for controlling tool access and user approval flows.

Read the full file on GitHub · 345 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 · 345 lines · 52 tokens per session scan A 12cb5a665f76

Subscribe to this mod's changes

claude-agent-sdk is a skill published in the GitHub repository emdashcodes/claude-code-plugins (13 stars, last pushed 1mo ago), licensed MIT. It adds 52 tokens to every session and 2,155 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.

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