●Change8

Migrating to Hermes Agent v2026.4.23

Version v2026.4.23 introduces 2 breaking changes. This guide details how to update your code.

Released: 4/23/2026

2
Breaking Changes
2
Migration Steps
15
Affected Symbols

⚠️ Check Your Code

If you use any of these symbols, you need to read this guide:

run_agent.pyagent/transports/tui_gatewayhermes --tuiAnthropicTransportChatCompletionsTransportResponsesApiTransportBedrockTransportregister_commanddispatch_toolpre_tool_calltransform_tool_resulttransform_terminal_outputhermes modelauto routing

Breaking Changes

●Issue #1

The transport layer has been refactored, extracting format conversion and HTTP transport into a pluggable architecture in `agent/transports/`. This may require updates to custom transport implementations.

●Issue #2

The default routing for auxiliary models has changed. Previously, aggregator users were silently routed to a cheap provider-side default. Now, `auto` routing defaults to the main model for side tasks across all users. This might affect performance or cost for specific auxiliary tasks if the main model is not optimized for them.

Migration Steps

  1. 1
    If you have custom transport implementations, review and adapt them to the new `agent/transports/` layer and the `Transport ABC`.
  2. 2
    Be aware that the default routing for auxiliary models has changed. If you relied on the previous default for specific auxiliary tasks, you may need to explicitly configure them.

Release Summary

Hermes Agent v0.11.0 introduces a complete rewrite of the interactive CLI to a React/Ink-based TUI, a pluggable transport architecture with native AWS Bedrock support, and five new inference paths. This release significantly expands the plugin surface and adds support for GPT-5.5 and QQBot.

Need More Details?

View the full release notes and all changes for Hermes Agent v2026.4.23.

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