CLAUDE API

Claude API version 2026-10-21 removes temperature, top_p and top_k, and new major SDKs (TypeScript 1.0, Python 2.0) send it by default. What breaks and how to migrate.

Which 429, 529 and 503 errors to retry across OpenAI, Claude, Gemini and Bedrock, how to read Retry-After, and a typed wrapper that skips quota errors.

Anthropic Python SDK 1.0 swaps httpx for httpx2, requires Python 3.10+, and drops temperature and Text Completions. Verified steps to upgrade safely.

The Claude API exports OpenTelemetry traces in beta. Set up SDK spans in TypeScript or Python, add a Console destination for API spans, and count tokens once.

Claude Files API and Skills API are GA: drop two beta headers, add file expiry up to 90 days, and switch to page cursors. Type-checked TS and Python steps.

Context engineering for agents, explained: caching, compaction, tool-result clearing, retrieval and subagents, with the exact Anthropic and OpenAI API knobs.

How tool calling works on the wire: JSON schema tools, parallel calls, tool_choice, strict mode and streaming deltas in Claude Messages vs OpenAI Responses.

Anthropic's own runs: a Fable 5.1 advisor added 1.7 points to Opus 5.5 for 2.1x the cost. When the Claude advisor tool pays, and when to raise effort instead.

Fable 5 prompt caching economics: cache-write vs cache-read pricing, 5-minute vs 1-hour TTL break-even math, and worked agent-loop examples.

Claude Fable 5 API production guide - adaptive thinking, rate limit strategy, streaming latency, fallback chains and a migration checklist from Opus 4.8.

How to ship Claude's Batch API in production. 50% cost savings, TypeScript SDK code, JSONL request format, and the async architecture gotchas that bite at 100k requests.

How to ship Claude's vision API in production. OCR, charts, UI audits, real cost numbers, TypeScript SDK code, and the gotchas that bite at 100k images a month.

A production guide to Claude's extended thinking mode. Real cost math, TypeScript SDK code, and the tasks where reasoning tokens are worth 3x the spend.

Cut Claude API spend by up to 90% with prompt caching. Real numbers, TypeScript SDK code, and the gotchas Anthropic's docs gloss over.

Master tool use in the Claude API. Schema design, retry logic, multi-step loops, and the failure modes that only show up at 10k calls a day.