Opus 4.8

Amp released Opus 4.8, a new AI coding agent that powers its 'smart' mode, replacing Opus 4.7. The model solves 62% of tasks in internal evaluations, up from 52% for its predecessor, by making more focused changes and verifying its own work more thoroughly. Opus 4.8 also offers a faster mode at 2.5× speed and 3× cheaper token costs.

Opus 4.8 now powers Amp's smart mode, replacing Opus 4.7. It is a better coding agent than Opus 4.7: more faithful to the prompt, tighter in the changes it makes, and better at checking its own work. In our internal evals it solved 62% of tasks, up from 4.7's 52% . Opus 4.7 was already strong on hard, multi-file work, and Opus 4.8 keeps that. What changes is how it gets there: with fewer wasted steps and more self-checking. The clearest difference is restraint and verification. Opus 4.7 can sometimes over-engineer, reaching for a more elaborate solution than the task needs. It also verifies its own work less, occasionally moving on even when a command's output is already warning that something is off. Opus 4.8 makes a more focused change that solves the specific intended task, then checks itself. It leans on a tighter write→test loop, often spinning up a quick script, test, or skill to confirm the change works before proceeding. In our evals it ran tests and code 15% more per task than 4.7. That restraint is easiest to see on hard tasks. On everyday work the two make a similar number of tool calls. The harder a task gets, the tighter 4.8 stays, just where 4.7 tends to run long and fail more often. Opus 4.8 is noticeably better at using its tools and sub-agents without being told to. When a task needs outside context, it actually calls librarian instead of inferring a library's behavior from the local code. Across our eval it reached for it 14 times, versus once for Opus 4.7. It also reaches for a repo's skills more often to verify its work, for example by driving the browser or the CLI, rather than just assuming the change worked. When it edits, it leans on edit file for surgical, in-place changes rather than rewriting whole files with create file . In our evals 79% of its file edits go through edit file , up from 63% on Opus 4.7. We dropped the Read tool from smart . Opus 4.8 is good enough at reading files straight from the shell with cat , rg , sed , and nl . It parallelizes those reads when it needs several files at once. Opus 4.8 has a fast mode at roughly 2.5× the speed. It now costs 2× base tokens, down from 6× on 4.7—3× cheaper. Toggle fast mode for a thread from the CLI command palette Ctrl+O → speed: use fast . Opus 4.8 stays close to what you ask, changes less to get there, and checks its own work. A few habits make it shine: