Claude Agent SDK
Claude Agent SDK (formerly Claude Code SDK) is Anthropic’s official SDK to “build production AI agents with Claude Code as a library” — “the same tools, agent loop, and context management that power Claude Code, programmable in Python and TypeScript.” It is the clearest artifact of the model-provider → agent-platform shift this wiki tracks: the harness itself, shipped as a building block. Source: official docs.
What it provides
The Claude Code harness, unbundled: built-in tools (Read/Write/Edit/Bash/Glob/Grep/WebSearch/WebFetch),
hooks (PreToolUse/PostToolUse/SessionStart… — the agent-guardrails insertion points),
subagents (agent-orchestration as a first-class option), MCP (model-context-protocol)
integration, sessions (resume/fork — durable-agents), and permissions. It even loads
.claude/ config — Skills, slash commands, CLAUDE.md memory, plugins — so this
wiki’s threads (skills, orchestration, durability, guardrails) are literally SDK features.
Where it sits
Anthropic now offers a three-rung ladder: the Client SDK (you implement the tool loop) → the Agent SDK (Claude runs the loop in your process) → Managed Agents (Anthropic runs the loop + sandbox). The Agent SDK is the harness-as-library middle rung — strong evidence for the spoke’s “the value moved to everything wrapped around the model, and the model vendor is now selling that wrapper too” thesis. (Note: from 2026-06-15 it draws on a separate Agent-SDK credit on subscription plans.)
Related
agentic-coding-harness · agent-orchestration · durable-agents · agent-guardrails · agent-skills · model-context-protocol · claude-managed-agents · anthropic · adk · agents-md