{"version":"2.1.248","anchor":"unreleased-mythos-and-next-generation-model-ids-in-the-bundl","canonical_anchor":"unreleased-mythos-and-next-generation-model-ids-in-the-bundl","heading":"Unreleased Mythos and next-generation model ids in the bundled tables","tier":"soon","area":"Models","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.248\/e\/unreleased-mythos-and-next-generation-model-ids-in-the-bundl","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.248","markdown":"### Unreleased Mythos and next-generation model ids in the bundled tables\n\nModel tables carry ids for a Mythos preview and a 5-series family, not selectable.\n\n**What**\n\nThe model tables shipped in this build carry ids for models that are not part of the current lineup, including a Mythos preview and a family of 5-series entries. They are data in constants and mapping tables only, so nothing here makes the models selectable or reachable, and the build ships no setting, flag or menu entry that turns them on.\n\n**Details**\n\n- The model constants list ids for Fable 5, Mythos 5, Opus 5 and Sonnet 5, with `claude-opus-4-8` positioned as the previous Opus and `claude-sonnet-4-6` as the previous Sonnet.\n- Mythos has full provider id mappings across Bedrock, Vertex, Foundry, Mantle and the gateway, so the routing tables would resolve it if it were ever requested.\n- A model list constant includes `claude-mythos-preview` and `claude-opus-4-6` together, and a separate mapping names a further id.\n- The bundled Anthropic client's deprecation table now covers `claude-mythos-preview` with an end-of-life date of June 30th, 2026.\n- `claude-mythos-preview` and `claude-opus-4-6` are both in the set that prints a console warning when used with non-adaptive thinking enabled.\n\n**Evidence**\n\n`\"claude-mythos-5\"`, `\"claude-mythos-preview\": \"June 30th, 2026\"`, `[\"claude-mythos-preview\", \"claude-opus-4-6\"]`\n\n- Area: Models\n- Tier: Nothing to try yet\n- Useful: 2\/5\n- Signal: 5\/5\n- Present in the build but not switched on"}