transports/v1.6.6

maximhq/bifrosttransports/v1.6.6Jul 24, 2026by akshaydeo

AI Summary

Transport release adding support for Anthropic's default fallback routing and mid-conversation tool changes, along with Opus 5 compatibility fixes.

Key Highlights

Support for Anthropic's `fallbacks: "default"` preset.
Support for `mid-conversation-tool-changes` beta header.
Opus 5 compatibility fix and surface inheritance.

New Features

Anthropic Default Fallback Routing
Mid-Conversation Tool Changes
Opus 5 support

Full Release Notes

## Bifrost HTTP Transport Release v1.6.6

# ✨ Features

- **Anthropic Default Fallback Routing** — Added support for Anthropic's `fallbacks: "default"` preset, preserving it through the Bifrost round-trip and injecting the `server-side-fallback-2026-07-01` beta header for default-routing requests.
- **Mid-Conversation Tool Changes** — Added support for the `mid-conversation-tool-changes-2026-07-01` beta header, enabled for Anthropic and Bedrock Mantle.

## 🐞 Fixed

- **Opus 5 Compatibility** — Added Opus 5 detection to the Anthropic provider so it inherits Opus 4.8's request surface: `budget_tokens`, `temperature`, `top_p`, and `top_k` are stripped, and native `effort`, fast mode, and mid-conversation system messages are enabled.

### Installation

#### Docker
```bash
docker run -p 8080:8080 maximhq/bifrost:v1.6.6
```

#### Binary Download
```bash
npx @maximhq/bifrost --transport-version v1.6.6
```

### Docker Images
- **`maximhq/bifrost:v1.6.6`** - This specific version
- **`maximhq/bifrost:latest`** - Latest version (updated with this release)

---
_This release was automatically created with dependencies: core `v1.7.4`, framework `v1.5.4`. All plugins have been validated and updated._