CLAUDE LABJP
MODEL — Claude Fable 5.1 and Claude Mythos 5.1 landed on September 1. They are the same underlying model; only the strength of the safeguards differsPRICING — Per-token rates hold at $10/$50 per MTok. What changed is cache reads, cut 75% to $0.25 per MTokCOST — How much that saves depends on your workload: roughly 25% for typical use, up to about 45% for context-heavy agentic work. Worth measuring your own split before quoting a numberBENCH — Terminal-Bench-Science 0.1 climbs from 24.7% on Fable 5 to 52.6%. Anthropic also states a standard error of 3.5-4.5 points, which is worth remembering before reading small gaps as realSAFEGUARDS — Sharper cyber safeguards cut interventions in Claude Code sessions by roughly 60% on average. Finding vulnerabilities is now allowed; developing exploits still is notAPI — New API accounts created from today can no longer edit prior context while preserving Claude's thinking transcript. It is an anti-distillation measure, and existing accounts are unaffected for nowMODEL — Claude Fable 5.1 and Claude Mythos 5.1 landed on September 1. They are the same underlying model; only the strength of the safeguards differsPRICING — Per-token rates hold at $10/$50 per MTok. What changed is cache reads, cut 75% to $0.25 per MTokCOST — How much that saves depends on your workload: roughly 25% for typical use, up to about 45% for context-heavy agentic work. Worth measuring your own split before quoting a numberBENCH — Terminal-Bench-Science 0.1 climbs from 24.7% on Fable 5 to 52.6%. Anthropic also states a standard error of 3.5-4.5 points, which is worth remembering before reading small gaps as realSAFEGUARDS — Sharper cyber safeguards cut interventions in Claude Code sessions by roughly 60% on average. Finding vulnerabilities is now allowed; developing exploits still is notAPI — New API accounts created from today can no longer edit prior context while preserving Claude's thinking transcript. It is an anti-distillation measure, and existing accounts are unaffected for now
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API & SDK/2026-08-30Advanced

Read the Catalog Your CLI Already Ships Before Bulk-Replacing Model IDs

A newer generation makes older model IDs look stale. Here is how to pull the catalog embedded in your installed binary, sort every reference into matched, date-mismatched, and malformed, and stop the replacement that would break working IDs.

API & SDK/2026-08-14Intermediate

Move the Prompt Tools API Into Your Own Scripts Before Workbench Closes on August 17

The legacy Workbench and three experimental prompt endpoints shut down on August 17, 2026. Here is how to count what actually depends on them, plus working local replacements for templatize_prompt and improve_prompt with real output.

API & SDK/2026-07-24Advanced

When Memory Store Listings Returned Half the Rows: Migrating to agent-memory-2026-07-22

agent-memory-2026-07-22 changed memories.list: fixed ordering, stricter depth, segment-based path_prefix matching. How an audit quietly halved, an access layer that survives it, and measured depth=1 traversal cost.

Claude Code/2026-07-15Advanced

The Types Landed, but Nothing Got Safer — Where I Delegated a JS→TS Migration to Claude Code, and Where I Didn't

A green tsc run does not mean any is gone. Measuring a migration by type coverage, drawing a clear line between what Claude Code handles well and what a human must decide, and a CI ratchet that refuses regressions.

API & SDK/2026-06-23Advanced

When Thinking Is Always On, Prefill Quietly Stops Working — Fixing Streaming and Token Budgets for Fable 5

Fable 5 thinks by default. Prefill no longer applies, the first streamed block isn't text, and max_tokens has to leave room for reasoning. Here is how I fixed those three broken assumptions in my own automated publishing pipeline.

API & SDK/2026-06-13Advanced

Auditing pinned model IDs before claude-sonnet-4 and claude-opus-4 retire from the API

On June 15, claude-sonnet-4 and claude-opus-4 retire from the API. Here is how to find every pinned model ID before then, measure output parity, and cut over safely with an alias layer and a fallback.

Claude Code/2026-05-17Intermediate

Six Months Until CocoaPods Shutdown — Migrating Beautiful HD Wallpapers to Firebase SPM with Claude Code

Firebase Apple SDK is dropping CocoaPods in October 2026. Here's how I migrated Beautiful HD Wallpapers — one of four iOS apps I run as an indie developer — to Swift Package Manager, and where Claude Code made the difference.

Claude Code/2026-05-02Advanced

Designing Zero-Downtime Database Migrations with Claude Code: A Production Operations Guide

A production guide to designing zero-downtime database migrations with Claude Code. Covers Expand-Contract, NOT NULL additions, renames, backfills, and subagent reviews — practical patterns that survive real production traffic.

API & SDK/2026-04-07Beginner

Claude Sonnet 4.5 1M Context Deprecation Guide — What to Do Before April 30

Claude Sonnet 4.5's 1M token context beta ends April 30, 2026. Migrate to Sonnet 4.6 with step-by-step code examples — no beta header required on the new model.

Claude AI/2026-03-26Beginner

Switching from ChatGPT to Claude (2026)

Comprehensive guide to migrating from ChatGPT to Claude. Learn why users are switching, step-by-step migration instructions, API code examples, and Claude's unique features in 2026.

API & SDK/2026-03-14Beginner

Claude Haiku 3 Deprecation (April 19, 2026): Complete Migration Guide to Claude Haiku 4.5

Claude Haiku 3 (claude-3-haiku-20240307) is being retired on April 19, 2026. This guide covers the deprecation timeline, what changes, and how to migrate to Claude Haiku 4.5 with ready-to-use code examples.