higress/plugins/wasm-go/extensions/model-router

Feature Description

The model-router plugin implements routing functionality based on the model parameter in LLM protocols.

Configuration Fields

Name	Data Type	Requirement	Default Value	Description
modelKey	string	Optional	model	Location of the model parameter in the request body
addProviderHeader	string	Optional	-	Which request header to add the provider name parsed from the model parameter
modelToHeader	string	Optional	-	Which request header to directly add the model parameter to
enableOnPathSuffix	array of string	Optional	["/completions","/embeddings","/images/generations","/audio/speech","/fine_tuning/jobs","/moderations","/image-synthesis","/video-synthesis","/rerank","/messages"]	Only effective for requests with these specific path suffixes, can be configured as "*" to match all paths
keepOriginalModelName	bool	Optional	false	Used with addProviderHeader. When set to true, the provider is still extracted into the header, but the model field in the request body is not rewritten

Runtime Properties

Plugin execution phase: Authentication phase Plugin execution priority: 900

Effect Description

Routing Based on Model Parameter

The following configuration is needed:

modelToHeader: x-higress-llm-model

The plugin extracts the model parameter from the request and sets it to the x-higress-llm-model request header for subsequent routing. For example, the original LLM request body is:

{
    "model": "qwen-long",
    "frequency_penalty": 0,
    "max_tokens": 800,
    "stream": false,
    "messages": [{
        "role": "user",
        "content": "What is the GitHub address of the Higress project's main repository?"
    }],
    "presence_penalty": 0,
    "temperature": 0.7,
    "top_p": 0.95
}

After processing by this plugin, the following request header will be added (can be used for route matching):

x-higress-llm-model: qwen-long

Extracting Provider Field from Model Parameter for Routing

Note that this mode requires the client to specify the provider in the model parameter using the / delimiter

The following configuration is needed:

addProviderHeader: x-higress-llm-provider

The plugin extracts the provider part (if any) from the model parameter in the request, sets it to the x-higress-llm-provider request header for subsequent routing, and rewrites the model parameter to only contain the model name part. For example, the original LLM request body is:

{
    "model": "dashscope/qwen-long",
    "frequency_penalty": 0,
    "max_tokens": 800,
    "stream": false,
    "messages": [{
        "role": "user",
        "content": "What is the GitHub address of the Higress project's main repository?"
    }],
    "presence_penalty": 0,
    "temperature": 0.7,
    "top_p": 0.95
}

After processing by this plugin, the following request header will be added (can be used for route matching):

x-higress-llm-provider: dashscope

The original LLM request body will be changed to:

{
    "model": "qwen-long",
    "frequency_penalty": 0,
    "max_tokens": 800,
    "stream": false,
    "messages": [{
        "role": "user",
        "content": "What is the GitHub address of the Higress project's main repository?"
    }],
    "presence_penalty": 0,
    "temperature": 0.7,
    "top_p": 0.95
}

Preserving Original Model Name (keepOriginalModelName)

When using AI model aggregation platforms (e.g. Bailian/DashScope) with third-party models, some model names inherently contain / (e.g. MiniMax/MiniMax-M2.7) and are not in provider/model format. In this case, using addProviderHeader would incorrectly rewrite the model field in the request body.

By setting keepOriginalModelName: true, you can keep the provider header extraction while preserving the original model field in the request body:

addProviderHeader: x-higress-llm-provider
keepOriginalModelName: true

For example, with model MiniMax/MiniMax-M2.7, after processing by the plugin:

• Request header x-higress-llm-provider is set to MiniMax
• The model field in the request body remains MiniMax/MiniMax-M2.7 (not rewritten)