Sending 40 Rows From Make to the Claude API Stops at Row 14 — Avoiding the 429 With One Subtraction
Why a no-code automation that sends spreadsheet rows to the Claude API one by one hits a 429 partway through, and how to fix it. Seven spacing strategies tested on a mock bucket, a formula for the Sleep delay, and settings that stop failed rows from vanishing.
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.
Before You Switch Models, Replay Your Own Call Shapes Against the Candidate for a Few Tokens
Change a model ID and the first production request is where a 400 shows up. Here is a small replay script that checks your own call shapes against a candidate model with max_tokens 16 before you switch.
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 Night Claude Returned 529, My Fallback Failed Too — Strip cache_control at the Provider Boundary
My Claude API fallback threw a TypeError because content blocks still carried cache_control when they reached another vendor. Here is the stripping function, the pre-send guard, and the weekly forced-fallback routine that finally made the fallback a real safety net.
I Send Images Twenty at a Time — The Day the 21st Image Changed the Rules for the Other 61
Sending 62 images in one request failed with invalid_request_error. The cause was the image count, not the payload size. Here is how I recounted visual tokens as 28px patches and built batches that respect count, dimensions, and payload at once.
The translation read perfectly and still crashed at runtime
When you translate app strings with the Claude API, the meaning can be right while the format specifiers quietly break. Here is a severity-aware acceptance check and a repair loop that only re-translates the broken lines.
The 400 that rejects a thinking block, and finding the edit that caused it
On Claude Fable 5.1, editing the system prompt, tools, or earlier messages before a thinking block makes the request fail with a 400. Here is how to check whether your own agent loop does that in a single request, and how to move a rebuilt system prompt and client-side trimming to patterns that leave the prefix untouched.
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.
The September Price Increase for Sonnet 5 Isn't Happening. Rebuilding a Forecast I Got Wrong in July
Sonnet 5's introductory $2/$10 pricing was supposed to rise to $3/$15 on September 1. It won't. Here's how to recompute your own effective cost from the usage numbers you already have, with working code.
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.