I think Anthropic silently edited the system card for Mythos 5 and Fable 5.
Left is the current version on their cdn, right is the one I saved on launch day.
Both say "June 9th" on the front page.
4:36 PM · Jun 12, 2026 · 50.1K Views
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Many users criticized Anthropic for making sneaky unversioned edits to the Claude Fable 5 and Mythos 5 system card, while some defended the company by noting the changelog and diffs provided.
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17.6%
Neg
82.4%
17 comments with sentiment.
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Theo - t3.gg@theo
Okay they did post a changelog, missed that my bad
Theo - t3.gg@theo
I think Anthropic silently edited the system card for Mythos 5 and Fable 5.
Left is the current version on their cdn, right is the one I saved on launch day.
Both say "June 9th" on the front page.
3hViews 9.2KLikes 107Bookmarks 6
Aight_Man@aight_cun
@theo Dude this guy is blind anthropic hater, *literally*, they have the whole ass changelog...
3hViews 1KLikes 4
devCansado@devcansado404
@theo classic ninja edits. u spend weeks tuning evals just for them to change shit under the hood. same date same version. then prod breaks and u think ur losing ur mind. pure gaslighting
2hViews 808
BenIt Pro@BennettBuhner
@theo Lmao Anthropic crosses every line I sswear
3hViews 193Likes 1
Conor Bronsdon@ConorBronsdon
@theo Maybe edit the original post to note that
3hViews 177Likes 1
Naloong@Naloong6369
@aight_cun @theo He's double butthurt because 1. They changed the SDK from sub usage to monthly credit system which killed his shitty wrapper 2. He can't afford it especially now with his stupid wrapper dead 3. His ego got killed because he realizes his "product" is useless and just a wrapper
2hViews 24Likes 2
Leathery@SolLeathery
@theo Do you think this? Or does a diff say that they're different?
3hViews 1.1KLikes 1
Nathan Clark@nathanclark_
@PaulTakisaki @theo
3hViews 16Likes 4
Neo@NeoAIForecast
@theo Sneaky.. classic anthropic move
3hViews 133Likes 1
Paweł Kula@pawel_plx
@theo yes, they said on the bottom of the card that it has been updated
3hViews 103Likes 1
Paul Takisaki@PaulTakisaki
@theo If the date stays the same, the changelog is the product. Model cards need versioning like APIs, not vibes with a PDF wrapper.
3hViews 239
Luis Catacora@lucatac0
@theo Claude can cite its sources, but apparently Anthropic can't version them correctly
3hViews 219
john@johnnysedh3lllo
@theo Anthropic when the one dev flips out:
3hViews 200
Shikhar@xikhar
@theo Common Misanthropic L
3hViews 188
Aryaman Shandilya@shandilyeah
@ConorBronsdon @theo and then post a changelog as well
3hViews 17Likes 2
sarz@sarzbuilds
@theo live on stream saw this lmao anthropic tryna be sneaky for no reason.
3hViews 163
Kingsley Onoh@kingsleyonoh_
@theo Live on stream 😄
3hViews 160
Yves@gas0linr
@theo Come one. Why are you hating so much against them?
3hViews 85
Uzi@uzairansar
@theo this is nuts
3hViews 67
rikk7@Henrik_92
@theo Crazy
3hViews 56
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