DeepSeek V4 Pro Real Cost: 120x Cache Gap Behind Sticker

V4 Pro lists at $0.435/M input — cache misses cost 120x more than hits, and thinking inflates output. Benchmarked vs GPT-5.5 and Sonnet 4.6 with raw data.

deepseekcost-optimization

Claude Code /cd: Switch Directories, Preserve Prompt Cache, 3 Edge Cases (2026)

Claude Code /cd added in v2.1.169 (2026-06-08): switch directories mid-session, keep prompt cache hot (90% input discount via 0.1x reads, 1.25x writes for 5-min TTL). 3 edge cases break it — different CLAUDE.md, MCP config drift, /add-dir conflicts. Worked example via ofox.ai.

claude-codeclaude

Claude Code Nested Sub-Agents: 5 Levels Deep, Token Math, 3 Pitfalls (2026)

Claude Code v2.1.172 (June 10) lets sub-agents spawn sub-agents up to 5 levels deep. Token costs compound per branch, each level gets its own context window. 3 anti-patterns: runaway nesting, Opus-everywhere, fake Agent() allowlists. Configure cheap delegation via ofox.

claude-codesubagents

Claude Code Safe Mode: 5 Things Disabled + When to Use Over /clear (2026)

Claude Code v2.1.169 --safe-mode: 1 flag disables 5 layers (CLAUDE.md, plugins, skills, hooks, MCP). Differs from /clear (1-turn wipe). Enable in 10s on Mac/Windows. 3-step triage, 8 errors mapped.

claude-codetutorial

Claude Fable 5 vs Opus 4.8 vs GPT-5.5: SWE-Bench, Pricing, When to Switch

Fable 5 hits 95.0% SWE-bench Verified and 80.3% SWE-bench Pro — 11 points over Opus 4.8, 21.7 over GPT-5.5. At $10/$50 it costs 2x Opus. When the upgrade pays.

claudegpt

Codex AGENTS.md Not Loading in Symlinked Workspaces: v0.138 Fix (2026)

Codex CLI v0.138 (Jun 8, 2026) finally loads AGENTS.md in symlinked + remote workspaces—PRs #26205, #26465. 3 verification steps, 7 error patterns, 32 KiB instruction cap, monorepo parent-dir fix. When to upgrade vs switch to GPT-5.3-Codex via ofox.

codexagents-md

Anthropic vs OpenAI Prompt Caching 2026: Cost Math + 3 Cache-Miss Fixes

Anthropic Claude cache reads: 0.1× input (90% off). OpenAI GPT-5.5 also 0.1× ($0.50/M vs $5/M). 5-min TTL, 1024 min tokens, 1.25× Anthropic writes vs free OpenAI writes. 3 cache-miss patterns + cost math on 10M tok/day workloads. A/B both via ofox.

claudeopenai

Apple's Third-Generation Foundation Models: A Developer's Read on WWDC 2026

Apple's AFM 3 lineup at WWDC 2026 — five models, a 20B sparse on-device LLM built on Instruction-Following Pruning, and a Private Cloud Compute extension to NVIDIA GPUs in Google Cloud. What's verified, what's spin, and what it changes for developers.

applefoundation-models

Claude API Error 529: 8 Fixes & Failover Guide (2026)

Claude 529 hit 4x in 2026 (3h+ outage Mar 18). 8 tier-ranked fixes: exponential backoff + sub-200ms failover to GPT-5 or Qwen-3.7-Max. Python & Node included.

claudeanthropic

CC Switch: One App for Claude Code, Codex + 5 AI CLIs (2026)

CC Switch v3.16.1 controls 7 AI CLIs — Claude Code, Codex, Gemini CLI, OpenCode, OpenClaw, Hermes Agent, Claude Desktop — via system tray. 50+ provider presets, 10-min install on macOS/Windows/Linux.

cc-switchclaude-code