# Sonnet 5

The standard engineering tier: focused edits, test writing, single-file authoring, most verification panels.

## What it is
The workhorse tier: focused code edits, single-file authoring, test writing, source-grounded summarization, and most verification panels. Fast enough to run several in parallel, capable enough that the top tier only reviews.

## Why
Most engineering work is bounded: a focused edit, a test, a well-specified port. The middle tier does it indistinguishably from the top tier at a fraction of the cost — so that's where the typing happens.

## How Andrew uses it
Delegated implementation legs land here by default when they're too judgment-bearing for the local model but don't need top-tier reasoning. Verify panels usually run a tier below the stage that authored the work.

## How to get it
Available via the Claude API and coding CLIs as the mid-tier model. Route your standard engineering here and reserve the top tier for review.

_Distilled from: method/models/sonnet-5.md_
