Opus 5.0
A flagship language model released by Anthropic, serving as the predecessor to Opus 5.5.
Timeline (last 90 days)
The posting user's tongue-in-cheek version evolution line is: Opus 3.0 was not very useful; Opus 4.7 could help with some basic tasks; Opus 5.0 was a good model; Opus 5.5 gave him the freedom to take time off.
The developer reported observing on Fable 5.0 that the writing style collapsed overnight from a Mythos-like style to one closer to Opus 5.0.
Versions Opus 4.7, 4.8, and 5.0 exhibited a decline in conversational quality, a heavier AI-like feel, and deteriorating task execution performance.
About a week before the release, Musk tweeted a prediction that Grok 4.7 should roughly match Opus 5.0, and had stated even earlier that it would surpass all current models.
On a three-sample math problem, DeepSeek V4.1 Flash scored 74 points, on par with Opus 5.0 and surpassing GLM's 67 points and V4 Pro's 62 points.
For most tasks, Fable called Opus 5.0, and only called itself for some tasks.
Out of cost considerations, the author chose to have Fable delegate most tasks to the relatively economical Opus 5.0 for execution.
All Facts (4)
The posting user's tongue-in-cheek version evolution line is: Opus 3.0 was not very useful; Opus 4.7 could help with some basic tasks; Opus 5.0 was a good model; Opus 5.5 gave him the freedom to take time off.
50%UnverifiedVersions Opus 4.7, 4.8, and 5.0 exhibited a decline in conversational quality, a heavier AI-like feel, and deteriorating task execution performance.
50%UnverifiedOn a three-sample math problem, DeepSeek V4.1 Flash scored 74 points, on par with Opus 5.0 and surpassing GLM's 67 points and V4 Pro's 62 points.
50%UnverifiedOut of cost considerations, the author chose to have Fable delegate most tasks to the relatively economical Opus 5.0 for execution.
50%