Skip to content

Release Notes: v0.17.0

Release Date: 2026-06-15

Highlights

  • Claude Fable 5 & Mythos 5: Support for Anthropic's latest frontier models
  • Claude 4.6-4.8: Full model constant support across Claude API, Bedrock, and Vertex AI
  • Claude 4.5: Complete coverage for Opus 4.5, Sonnet 4.5, and Haiku 4.5

New Model Constants

Claude Fable 5 / Mythos 5 (Latest Frontier)

Constant Model ID Notes
ClaudeFable5 claude-fable-5 Most capable widely released model
ClaudeMythos5 claude-mythos-5 Project Glasswing (limited availability)

Claude 4.8 / 4.7 / 4.6 (Dateless Format)

Starting with Claude 4.6, model IDs use a dateless format (still pinned snapshots).

Constant Model ID Notes
ClaudeOpus4_8 claude-opus-4-8 Latest Opus-tier model
ClaudeOpus4_7 claude-opus-4-7 Legacy
ClaudeOpus4_6 claude-opus-4-6 Legacy
ClaudeSonnet4_6 claude-sonnet-4-6 Latest Sonnet-tier model

AWS Bedrock

Constant Bedrock Model ID
BedrockClaudeFable5 anthropic.claude-fable-5
BedrockClaudeOpus4_8 anthropic.claude-opus-4-8
BedrockClaudeOpus4_7 anthropic.claude-opus-4-7
BedrockClaudeOpus4_6 anthropic.claude-opus-4-6-v1
BedrockClaudeSonnet4_6 anthropic.claude-sonnet-4-6
BedrockClaudeOpus4_5 anthropic.claude-opus-4-5-20251101-v1:0
BedrockClaudeSonnet4_5 anthropic.claude-sonnet-4-5-20250929-v1:0
BedrockClaudeHaiku4_5 anthropic.claude-haiku-4-5-20251001-v1:0

Google Vertex AI

Constant Vertex Model ID
VertexClaudeFable5 claude-fable-5
VertexClaudeOpus4_8 claude-opus-4-8
VertexClaudeOpus4_7 claude-opus-4-7
VertexClaudeOpus4_6 claude-opus-4-6
VertexClaudeSonnet4_6 claude-sonnet-4-6
VertexClaudeOpus4_5 claude-opus-4-5@20251101
VertexClaudeSonnet4_5 claude-sonnet-4-5@20250929
VertexClaudeHaiku4_5 claude-haiku-4-5@20251001

Deprecations

The following models are marked as deprecated per Anthropic's timeline:

Model Retirement Date
Claude Opus 4.1 August 5, 2026
Claude Opus 4 June 15, 2026
Claude Sonnet 4 June 15, 2026

Migrate to Claude Opus 4.8 or Claude Sonnet 4.6 respectively.

Usage

import (
    "github.com/plexusone/omnillm-core"
    "github.com/plexusone/omnillm-core/models"
)

// Latest models
client.Model = omnillm.ModelClaudeFable5      // Frontier
client.Model = omnillm.ModelClaudeOpus4_8     // Latest Opus
client.Model = omnillm.ModelClaudeSonnet4_6   // Latest Sonnet

// Cloud providers
client.Model = models.BedrockClaudeOpus4_8
client.Model = models.VertexClaudeSonnet4_6

Installation

go get github.com/plexusone/omnillm-core@v0.17.0

Upgrade Notes

This is a backwards-compatible release. No breaking changes.