选择 Claude 模型
Opus/Sonnet/Haiku 之间的权衡以及如何选择——无需靠猜。
Token、上下文与定价
正确计算 token、max_tokens 与上下文窗口的区别，以及如何估算成本。
你的第一次 API 调用
安装 SDK、完成鉴权，并用 Python、TypeScript 或 cURL 真实地调用 Claude。
API Version 2026-10-21 — The First Breaking Version in Three Years
Claude's anthropic-version header moved for the first time since 2023. What breaks, why your package manager decides when you adopt it, and the exact upgrade order.
流式输出与多轮对话
在无状态 API 上流式返回响应并自行管理对话历史。
工具使用 / 函数调用
定义工具、运行智能体循环并处理结果——包括会导致 400 的三条消息形态规则，以及为什么 tool_choice "any" 和 "tool" 现在在最新的 Claude 模型上会报错。
Code Execution Tool — Sandboxed Bash, Files, and Python
Anthropic's server-side sandbox lets Claude run Bash, edit files, and execute Python — with 5 GiB of RAM, 30-day container reuse, and a 1,550-hour monthly free tier. The three tool versions, what each adds, when it's free, and the file-capture gotcha nobody documents.
视觉、PDF 与文件输入
发送图片和文档，并通过 file_id 复用已上传的文件。
结构化输出
获得符合 schema、可依赖的 JSON——而不是靠提示词碰运气。
扩展思考与思考力度
自适应推理与思考力度控制——按工作负载选择深度。
effort 调优：5 个级别、各模型默认值与缓存陷阱
2026 年 7 月的 effort 参数有五个级别——low、medium、high、xhigh、max——并且位于 output_config 内部，而不是顶层。它影响工具调用（而不仅是思考），在对话中途更改会使提示缓存失效，并且每个模型的推荐起点各不相同。实用的调优指南。
The advisor tool: Sonnet does the work, Fable does the thinking
The advisor server-tool (beta advisor-tool-2026-03-01) lets a fast executor model consult a stronger model mid-turn. Full field reference, the token-accounting trap most integrators miss, the model pairing matrix, and the exact prompts Anthropic ships in production.
Task Budgets — Advisory Token Caps That Make Agents Finish Gracefully
The March 2026 Messages-API beta gives Claude a token budget for the whole agentic loop — thinking, tool calls, tool results, output — so long-running agents self-regulate and wrap up cleanly instead of running away. How the countdown works, why it's advisory not enforced, and how to size it so it doesn't cause refusal-like behavior.
提示缓存与成本优化
复用稳定的提示前缀以降低成本和延迟——以及那个会让它失效的陷阱。
Cache Diagnostics — Find Out Exactly Why Your Cache Missed
Stop guessing why cache_read_input_tokens is zero. The API will tell you which part of your prompt diverged, and by how many tokens.
Message Batches — Async Jobs at 50% Off
Cut cost in half and lift throughput by moving bulk work to the async Batches API — with the gotchas that trip people up.
Mid-Conversation System Messages
Steer a long agent session without blowing up the prompt cache — the new system role you can append after any user turn.
Mid-Conversation Tool Changes
Add and retire tools between turns without invalidating the prompt cache — the Opus 5 beta that fixes the biggest hidden tax on long agent sessions.
在 API 上构建智能体
单次调用 vs 工作流 vs 自定义智能体——决策测试与循环设计。
托管智能体
Anthropic 托管的智能体循环：agent 与 session 的区别、环境、记忆、保险库以及定时部署（cron）。
Managed Agents Memory Stores
The July 2026 beta — server-side persistent memory that mounts into a Managed Agents sandbox, with versioning, audit trail, and redaction.
Managed Agents Session Budgets
The August 2026 beta — hard dollar caps on a Managed Agents session, enforced at public list rates, with the budget_reached stop reason, the one-request overshoot, and the pause-and-resume model.
Managed Agents Domain Restrictions
The August 26, 2026 beta — allowed_domains, blocked_domains, max_content_tokens, and user_location on web_search and web_fetch inside Managed Agents. Format rules, multiagent semantics, mid-session updates, and the url_not_allowed error.
Cowork 与智能体团队
智能化的桌面工作空间，以及作为产品的多智能体协作。
MCP 与连接工具
在请求上声明 MCP 服务器，以及 MCP 与其他工具类型的定位对比。
MCP 2026-07-28: The Stateless Spec
The biggest MCP revision since launch: the session is gone, every request self-describes, and any server instance can answer any call. What actually changed on July 28, 2026, and how to migrate without breaking today's servers.
MCP Apps: Interactive UIs Inside a Tool Call
MCP Apps (SEP-1865) lets an MCP server ship an HTML UI that the client renders inside a sandboxed iframe — with every action still routed through the standard JSON-RPC audit path. What the spec actually says, what to build with it, and what to refuse to build.
MCP Tasks: Long-Running Work Without the Session
The 2026-07-28 stateless MCP spec killed the session — so how do you model a 20-minute CI job, a batch import, or a human approval gate? With the official Tasks extension (SEP-2663). Full lifecycle, wire protocol, migration from the old experimental Tasks API, and the polling/notification patterns that actually work in production.
Playwright MCP: The Deep Practical Guide (2026)
Microsoft's Playwright MCP is now the #1 MCP server in the world — ahead of GitHub and Figma. The bit almost nobody teaches: the default accessibility-snapshot mode is not just faster than vision, it's a completely different automation paradigm. Profiles, opt-in caps, browser-extension mode that attaches to your real Chrome, the token-cost fight against Playwright-as-a-Skill, and the security line you must not cross.
安全、拒答与降级
优雅地处理拒答，并将其与分类器拦截区分开来。
Server-Side Fallbacks & Fallback Credit
The Opus 5 beta that turns a Fable 5 / Opus 5 refusal into a normal answer inside one API call — plus the credit token that stops you from paying the prompt cache twice on the retry.
错误、速率限制与可靠性
错误对照表、带退避的重试、速率限制层级，以及模型迁移。
记忆与上下文编辑
为智能体提供持久化记忆和自动修剪的上下文 —— 客户端实现的 memory tool，配合在长时间运行中清除陈旧工具结果的上下文编辑。
Conversation Compaction — Summarize History Server-Side and Keep Going
The Messages API can summarize a conversation into one signed block you send back in place of the messages it replaces. The four flavors (on-demand, keep-tail, background, threshold), the swap rules, the two mistakes that fail silently with HTTP 200, and what a summary can never carry.
Tool Search & Deferred Loading
Scale to thousands of tools without context bloat: how defer_loading and the tool search tool actually work, the five 400s they produce, and why your request body does not get smaller.
Message Threads — Send Only the New Turn
The Messages API can keep your conversation on the server and let each turn send only the new messages. What it actually saves (bytes and latency, not tokens), the replay path you must build before you ship, the three field groups, and the 4-breakpoint cache limit.
Programmatic Tool Calling
Let Claude call your tools from Python inside the code-execution sandbox — cutting round-trips and keeping intermediate results out of context.
The Admin API: automate your Claude org
The operator's guide to Anthropic's Admin API — list members, invite users, run RBAC groups, offboard cleanly. Console + Claude Enterprise, with the seat-pool and SSO gotchas that trip real teams.
Agent Observability: Tracing an Agent You Can't Reproduce
An agent run is a non-deterministic distributed trace, so you cannot debug it by re-running it — you have to have recorded it. This page covers what to record: the OpenTelemetry GenAI span shapes (and why every gen_ai.* attribute is still 'Development'), Claude Code's exact metric and event names, the request-id that links your trace to Anthropic support, and the three privacy traps in agent telemetry.
First-Party OpenTelemetry Tracing: Two Paths, One Trace
Since October 2026 the Claude API and the Claude SDK emit OpenTelemetry spans themselves — no hand-rolled instrumentation. But the two paths overlap, and summing both will double your token numbers. This page covers the setup for each, the one rule that keeps token counts honest, the traceparent flag that silently deletes your traces, and the delivery rules that disable a destination after 24 hours.
The Usage & Cost Analytics API: Attribute Every Dollar
The practical guide to Claude's Usage and Cost Analytics API — the beta that replaced the legacy usage_report and cost_report endpoints. Row shape, the five-dimension limit, actor semantics, the 100x cents footgun, data-freshness rules that break naive dashboards, and the legacy migration table.
Inference Hooks: inline DLP for Claude Enterprise
The operator's guide to Claude Enterprise Inference Hooks — the HTTPS webhook that lets your DLP server allow or deny every prompt across chat, Claude Code, and Cowork, before the model sees it. Full spec, verdict schema, signing, rollout playbook.
User Profiles & Enforcement: Don't Let One Customer Ban Your Whole Org
The operator's guide to Claude API user profiles — attribute every request to an end customer so a safety restriction or ban lands on one profile instead of your entire organization. Full field reference, the four enforcement_status values, the enac_ action schema, organization webhooks, and the polling loop you need because event delivery isn't live yet.