{"version":"2.1.67","anchor":"automatic-legacy-opus-model-string-migration","canonical_anchor":"automatic-legacy-opus-model-string-migration","heading":"Automatic Legacy Opus Model String Migration","tier":null,"area":null,"scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.67\/e\/automatic-legacy-opus-model-string-migration","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.67","markdown":"### Automatic Legacy Opus Model String Migration\n\n**What**\n\nUsers configured with explicit old-format Opus model IDs (`claude-opus-4-20250514`, `claude-opus-4-1-20250805`, `claude-opus-4-0`, `claude-opus-4-1`) are automatically migrated to the canonical `opus` alias. A notification \"Model updated to Opus 4.6\" is shown briefly after the migration.\n\n**Details**\n\n- Applies to first-party users only\n- A new allowlist (`fXz`) defines the four legacy Opus model strings subject to migration\n- The previous Opus 4.5 \u2192 Pro migration notification (\"Model updated to Opus 4.5\") has been replaced by this updated path\n\n**Evidence**\n\nLegacy Opus migration (search for `\"tengu_legacy_opus_migration\"` and `\"legacyOpusMigrationTimestamp\"`)"}