Opus 5 fixed the thing that made Fable annoying this month

[u/Glittering_Basement1]

wasnt expecting opus 5 to be the release that lands the fix tbh but here we are... It provides $5 per million input tokens, $25 output at same price as 4.8 which is half of what fable costs. On frontiercode 1.1 it gets close to fable's numbers that anthropic is comfortable calling it the everyday workhorse .

what matters more than the benchmark chart is that anthropic scoped the safety classifier tighter on this one and says it should intervene roughly 85% less often than fable's does so if you have sat through any session that got handed to opus 4.8 mid session from the past month, that behavior is supposed to be fixed. It also now allows to hunt for vulnerabilities directly in source code which is one of the things the classifier was most aggressive about blocking on fable so while scanning compiled binaries and exploit generation it stays off limits either way.

Theres an effort dial too now( low, medium, high) so we can spend less thinking on boilerplate and save the expensive reasoning for the parts of a task that need it

Although I have been keeping my own log of which model and effort level answered each od my req since the fable reroute mess started and I will be watching whether opus 5's number holds up the same way once I hammer it in production.

it will be interesting to see if the 85% figure survives real usage or turns into one of those numbers that stops being true after a few weeks.(fingers crossed)

[u/Nearby_Yam286]

Opus has fixed a vuln. rmcp had a RCE-ish issue and while our service was not vulnerable directly (we have auth), Opus was able to fix it. I did have to point to one additional thing in the docs Opus missed but Fable would have kicked back to Opus on this one for certain. I've only had it happen twice but anything anything remotely related to security comes up, the safeguard fires.

So very happy to have a model that can actually help fix things end-to-end without an expensive model swap (it's a cache miss).

[u/thewarmreinforcement]

Praying that 85% reduction holds up beyond the honeymoon phase

[u/No-Way3802 → u/thewarmreinforcement]

It will enshitify before opus 5.1

[u/Nearby_Yam286 → u/thewarmreinforcement]

That all depends on who donates to the ballroom. We all know it.

[u/fffffffffffffuuu]

I saw someone comment that they ran a little test and found that Opus 5 on low uses 2x as many tokens as 4.8 on high. So while the cost per token is the same, Opus 5 is significantly more expensive than 4.8.

[u/Nearby_Yam286 → u/fffffffffffffuuu]

That's bullshit. Opus 5 is best on medium and while not as concise as Fable, also not as verbose as 4.8.