❯ Rumor: Anthropic’s New Models Marshmallow and Melon Surface, Unconfirmed

RUMORDevelopers claim to have spotted two unreleased model codenames, Marshmallow and Melon, reportedly corresponding to an Opus update and a new Haiku. So far, the report comes from a single account only, Anthropic has not confirmed anything, and no second independent source has followed up.

CREDIBILITYThere is only so much to glean from the codenames themselves. Over the past year, Anthropic’s naming system has shifted from numeric sequences to word-based codenames like Fable and Mythos, so internal codenames do not necessarily map one-to-one to final product names. Previously, in March, the source code of the Claude Code command-line tool leaked a batch of unreleased features — code trails are indeed a common leak path at this company, but a trail is not a timeline.

STAKESThe timing is worth examining: Fable 5’s enterprise spend was just surpassed by its own Opus 5, giving Anthropic a clear motive to quickly fill the cheaper and faster tier. If the Haiku line does get an update, the most direct impact will be on pay-as-you-go agent-style applications, whose cost structures are most sensitive to small-model pricing.

▪ SIGNALA codename leak is only worth as much as whether it lands at a moment when a vendor is being forced to accelerate.