Haiku 5.5 is cheaper per token, but your bill jumps fivefold past about 77k Haiku 4.5 tokens
On the price sheet, Haiku 5.5 costs roughly a tenth of Haiku 4.5. But the same text becomes about 30% more tokens, and a prompt over 100k tokens is billed at five times the rate. Here is the boundary in Haiku 4.5 terms, a script I actually ran, and the changes that return a 400.
Before Sonnet 4.5 retires, one script to find the arguments that will return a 400
claude-sonnet-4-5 retires on November 30. Swapping the model ID is not enough: budget_tokens, prefill, and tool_choice will fail. Here is a scanner built from the official migration guide, its real output, and the order I would fix things in.
claude-sonnet-4-5 stops on November 30 — I checked the bill before calling its replacement cheaper
claude-sonnet-4-5-20250929 retires on November 30, 2026. The recommended claude-sonnet-5-5 has lower list prices, but a new tokenizer and a 400 on temperature change the math. After reading, you can audit your own calls and plan the switch in order.
The morning a deprecation notice appeared, I checked versions before editing config
Claude Desktop and Cowork stop accepting older managed-configuration spellings on October 7. Here is how I sorted mine into what to fix now, what to fix after upgrading, and what changes meaning on its own.
inferenceGatewayHeaders still works today. At noon on October 7 it falls back to a default
I read the deprecation notice that started appearing on September 10 as a spelling cleanup. After the cut-off, the old names are not ignored — they fall back to a fail-closed value or a default. Here is the old-to-new map and a script that audits your config in one pass.
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.
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.
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, finding every call site with ast, and measured depth=1 traversal cost.
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.
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.
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.
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.