Replace model-router and model-mapper with Go implementation (#3317)

2026-06-09 20:57:32 +08:00 · 2026-01-13 20:14:29 +08:00
parent 032a69556f
commit e23ab3ca7c
14 changed files with 1418 additions and 0 deletions
--- a/plugins/wasm-go/extensions/model-router/Makefile
+++ b/plugins/wasm-go/extensions/model-router/Makefile
@@ -0,0 +1,2 @@
+build-go:
+	GOOS=wasip1 GOARCH=wasm go build -buildmode=c-shared -o main.wasm main.go
--- a/plugins/wasm-go/extensions/model-router/README.md
+++ b/plugins/wasm-go/extensions/model-router/README.md
@@ -0,0 +1,98 @@
+## 功能说明
+`model-router`插件实现了基于LLM协议中的model参数路由的功能
+
+## 配置字段
+
+| 名称                 | 数据类型        | 填写要求                | 默认值                   | 描述                                                  |
+| -----------          | --------------- | ----------------------- | ------                   | -------------------------------------------           |
+| `modelKey`           | string          | 选填                    | model                    | 请求body中model参数的位置                             |
+| `addProviderHeader`  | string          | 选填                    | -                        | 从model参数中解析出的provider名字放到哪个请求header中 |
+| `modelToHeader`      | string          | 选填                    | -                        | 直接将model参数放到哪个请求header中                   |
+| `enableOnPathSuffix` | array of string | 选填                    | ["/completions","/embeddings","/images/generations","/audio/speech","/fine_tuning/jobs","/moderations","/image-synthesis","/video-synthesis","/rerank","/messages"] | 只对这些特定路径后缀的请求生效，可以配置为 "*" 以匹配所有路径 |
+
+## 运行属性
+
+插件执行阶段：认证阶段
+插件执行优先级：900
+
+## 效果说明
+
+### 基于 model 参数进行路由
+
+需要做如下配置：
+
+```yaml
+modelToHeader: x-higress-llm-model
+```
+
+插件会将请求中 model 参数提取出来，设置到 x-higress-llm-model 这个请求 header 中，用于后续路由，举例来说，原生的 LLM 请求体是：
+
+```json
+{
+    "model": "qwen-long",
+    "frequency_penalty": 0,
+    "max_tokens": 800,
+    "stream": false,
+    "messages": [{
+        "role": "user",
+        "content": "higress项目主仓库的github地址是什么"
+    }],
+    "presence_penalty": 0,
+    "temperature": 0.7,
+    "top_p": 0.95
+}
+```
+
+经过这个插件后，将添加下面这个请求头(可以用于路由匹配)：
+
+x-higress-llm-model: qwen-long
+
+### 提取 model 参数中的 provider 字段用于路由
+
+> 注意这种模式需要客户端在 model 参数中通过`/`分隔的方式，来指定 provider
+
+需要做如下配置：
+
+```yaml
+addProviderHeader: x-higress-llm-provider
+```
+
+插件会将请求中 model 参数的 provider 部分（如果有）提取出来，设置到 x-higress-llm-provider 这个请求 header 中，用于后续路由，并将 model 参数重写为模型名称部分。举例来说，原生的 LLM 请求体是：
+
+```json
+{
+    "model": "dashscope/qwen-long",
+    "frequency_penalty": 0,
+    "max_tokens": 800,
+    "stream": false,
+    "messages": [{
+        "role": "user",
+        "content": "higress项目主仓库的github地址是什么"
+    }],
+    "presence_penalty": 0,
+    "temperature": 0.7,
+    "top_p": 0.95
+}
+```
+
+经过这个插件后，将添加下面这个请求头(可以用于路由匹配)：
+
+x-higress-llm-provider: dashscope
+
+原始的 LLM 请求体将被改成：
+
+```json
+{
+    "model": "qwen-long",
+    "frequency_penalty": 0,
+    "max_tokens": 800,
+    "stream": false,
+    "messages": [{
+        "role": "user",
+        "content": "higress项目主仓库的github地址是什么"
+    }],
+    "presence_penalty": 0,
+    "temperature": 0.7,
+    "top_p": 0.95
+}
+```
--- a/plugins/wasm-go/extensions/model-router/README_EN.md
+++ b/plugins/wasm-go/extensions/model-router/README_EN.md
@@ -0,0 +1,97 @@
+## 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 |
+
+## Runtime Properties
+
+Plugin execution phase: Authentication phase
+Plugin execution priority: 900
+
+## Effect Description
+
+### Routing Based on Model Parameter
+
+The following configuration is needed:
+
+```yaml
+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:
+
+```json
+{
+    "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:
+
+```yaml
+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:
+
+```json
+{
+    "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:
+
+```json
+{
+    "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
+}
--- a/plugins/wasm-go/extensions/model-router/go.mod
+++ b/plugins/wasm-go/extensions/model-router/go.mod
@@ -0,0 +1,24 @@
+module model-router
+
+go 1.24.1
+
+toolchain go1.24.7
+
+require (
+	github.com/higress-group/proxy-wasm-go-sdk v0.0.0-20251103120604-77e9cce339d2
+	github.com/higress-group/wasm-go v1.0.7-0.20251209122854-7e766df5675c
+	github.com/stretchr/testify v1.9.0
+	github.com/tidwall/gjson v1.18.0
+	github.com/tidwall/sjson v1.2.5
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/tetratelabs/wazero v1.7.2 // indirect
+	github.com/tidwall/match v1.1.1 // indirect
+	github.com/tidwall/pretty v1.2.1 // indirect
+	github.com/tidwall/resp v0.1.1 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
--- a/plugins/wasm-go/extensions/model-router/go.sum
+++ b/plugins/wasm-go/extensions/model-router/go.sum
@@ -0,0 +1,30 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/higress-group/proxy-wasm-go-sdk v0.0.0-20251103120604-77e9cce339d2 h1:NY33OrWCJJ+DFiLc+lsBY4Ywor2Ik61ssk6qkGF8Ypo=
+github.com/higress-group/proxy-wasm-go-sdk v0.0.0-20251103120604-77e9cce339d2/go.mod h1:tRI2LfMudSkKHhyv1uex3BWzcice2s/l8Ah8axporfA=
+github.com/higress-group/wasm-go v1.0.7-0.20251209122854-7e766df5675c h1:DdVPyaMHSYBqO5jwB9Wl3PqsBGIf4u29BHMI0uIVB1Y=
+github.com/higress-group/wasm-go v1.0.7-0.20251209122854-7e766df5675c/go.mod h1:uKVYICbRaxTlKqdm8E0dpjbysxM8uCPb9LV26hF3Km8=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/tetratelabs/wazero v1.7.2 h1:1+z5nXJNwMLPAWaTePFi49SSTL0IMx/i3Fg8Yc25GDc=
+github.com/tetratelabs/wazero v1.7.2/go.mod h1:ytl6Zuh20R/eROuyDaGPkp82O9C/DJfXAwJfQ3X6/7Y=
+github.com/tidwall/gjson v1.14.2/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
+github.com/tidwall/gjson v1.18.0 h1:FIDeeyB800efLX89e5a8Y0BNH+LOngJyGrIWxG2FKQY=
+github.com/tidwall/gjson v1.18.0/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
+github.com/tidwall/match v1.1.1 h1:+Ho715JplO36QYgwN9PGYNhgZvoUSc9X2c80KVTi+GA=
+github.com/tidwall/match v1.1.1/go.mod h1:eRSPERbgtNPcGhD8UCthc6PmLEQXEWd3PRB5JTxsfmM=
+github.com/tidwall/pretty v1.2.0/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
+github.com/tidwall/pretty v1.2.1 h1:qjsOFOWWQl+N3RsoF5/ssm1pHmJJwhjlSbZ51I6wMl4=
+github.com/tidwall/pretty v1.2.1/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
+github.com/tidwall/resp v0.1.1 h1:Ly20wkhqKTmDUPlyM1S7pWo5kk0tDu8OoC/vFArXmwE=
+github.com/tidwall/resp v0.1.1/go.mod h1:3/FrruOBAxPTPtundW0VXgmsQ4ZBA0Aw714lVYgwFa0=
+github.com/tidwall/sjson v1.2.5 h1:kLy8mja+1c9jlljvWTlSazM7cKDRfJuR/bOJhcY5NcY=
+github.com/tidwall/sjson v1.2.5/go.mod h1:Fvgq9kS/6ociJEDnK0Fk1cpYF4FIW6ZF7LAe+6jwd28=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
--- a/plugins/wasm-go/extensions/model-router/main.go
+++ b/plugins/wasm-go/extensions/model-router/main.go
@@ -0,0 +1,259 @@
+package main
+
+import (
+	"bytes"
+	"io"
+	"mime"
+	"mime/multipart"
+	"net/http"
+	"net/textproto"
+	"strings"
+
+	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm"
+	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm/types"
+	"github.com/higress-group/wasm-go/pkg/log"
+	"github.com/higress-group/wasm-go/pkg/wrapper"
+	"github.com/tidwall/gjson"
+	"github.com/tidwall/sjson"
+)
+
+const (
+	DefaultMaxBodyBytes = 100 * 1024 * 1024 // 100MB
+)
+
+func main() {}
+
+func init() {
+	wrapper.SetCtx(
+		"model-router",
+		wrapper.ParseConfig(parseConfig),
+		wrapper.ProcessRequestHeaders(onHttpRequestHeaders),
+		wrapper.ProcessRequestBody(onHttpRequestBody),
+		wrapper.WithRebuildAfterRequests[ModelRouterConfig](1000),
+		wrapper.WithRebuildMaxMemBytes[ModelRouterConfig](200*1024*1024),
+	)
+}
+
+type ModelRouterConfig struct {
+	modelKey           string
+	addProviderHeader  string
+	modelToHeader      string
+	enableOnPathSuffix []string
+}
+
+func parseConfig(json gjson.Result, config *ModelRouterConfig) error {
+	config.modelKey = json.Get("modelKey").String()
+	if config.modelKey == "" {
+		config.modelKey = "model"
+	}
+	config.addProviderHeader = json.Get("addProviderHeader").String()
+	config.modelToHeader = json.Get("modelToHeader").String()
+
+	enableOnPathSuffix := json.Get("enableOnPathSuffix")
+	if enableOnPathSuffix.Exists() && enableOnPathSuffix.IsArray() {
+		for _, item := range enableOnPathSuffix.Array() {
+			config.enableOnPathSuffix = append(config.enableOnPathSuffix, item.String())
+		}
+	} else {
+		// Default suffixes if not provided
+		config.enableOnPathSuffix = []string{
+			"/completions",
+			"/embeddings",
+			"/images/generations",
+			"/audio/speech",
+			"/fine_tuning/jobs",
+			"/moderations",
+			"/image-synthesis",
+			"/video-synthesis",
+			"/rerank",
+			"/messages",
+		}
+	}
+	return nil
+}
+
+func onHttpRequestHeaders(ctx wrapper.HttpContext, config ModelRouterConfig) types.Action {
+	path, err := proxywasm.GetHttpRequestHeader(":path")
+	if err != nil {
+		return types.ActionContinue
+	}
+
+	// Remove query parameters for suffix check
+	if idx := strings.Index(path, "?"); idx != -1 {
+		path = path[:idx]
+	}
+
+	enable := false
+	for _, suffix := range config.enableOnPathSuffix {
+		if suffix == "*" || strings.HasSuffix(path, suffix) {
+			enable = true
+			break
+		}
+	}
+
+	if !enable {
+		ctx.DontReadRequestBody()
+		return types.ActionContinue
+	}
+
+	if !ctx.HasRequestBody() {
+		return types.ActionContinue
+	}
+
+	// Prepare for body processing
+	proxywasm.RemoveHttpRequestHeader("content-length")
+	// 100MB buffer limit
+	ctx.SetRequestBodyBufferLimit(DefaultMaxBodyBytes)
+
+	return types.HeaderStopIteration
+}
+
+func onHttpRequestBody(ctx wrapper.HttpContext, config ModelRouterConfig, body []byte) types.Action {
+	contentType, err := proxywasm.GetHttpRequestHeader("content-type")
+	if err != nil {
+		return types.ActionContinue
+	}
+
+	if strings.Contains(contentType, "application/json") {
+		return handleJsonBody(ctx, config, body)
+	} else if strings.Contains(contentType, "multipart/form-data") {
+		return handleMultipartBody(ctx, config, body, contentType)
+	}
+
+	return types.ActionContinue
+}
+
+func handleJsonBody(ctx wrapper.HttpContext, config ModelRouterConfig, body []byte) types.Action {
+
+	modelValue := gjson.GetBytes(body, config.modelKey).String()
+	if modelValue == "" {
+		return types.ActionContinue
+	}
+
+	if config.modelToHeader != "" {
+		_ = proxywasm.ReplaceHttpRequestHeader(config.modelToHeader, modelValue)
+	}
+
+	if config.addProviderHeader != "" {
+		parts := strings.SplitN(modelValue, "/", 2)
+		if len(parts) == 2 {
+			provider := parts[0]
+			model := parts[1]
+			_ = proxywasm.ReplaceHttpRequestHeader(config.addProviderHeader, provider)
+
+			newBody, err := sjson.SetBytes(body, config.modelKey, model)
+			if err != nil {
+				log.Errorf("failed to update model in json body: %v", err)
+				return types.ActionContinue
+			}
+			_ = proxywasm.ReplaceHttpRequestBody(newBody)
+			log.Debugf("model route to provider: %s, model: %s", provider, model)
+		} else {
+			log.Debugf("model route to provider not work, model: %s", modelValue)
+		}
+	}
+
+	return types.ActionContinue
+}
+
+func handleMultipartBody(ctx wrapper.HttpContext, config ModelRouterConfig, body []byte, contentType string) types.Action {
+	_, params, err := mime.ParseMediaType(contentType)
+	if err != nil {
+		log.Errorf("failed to parse content type: %v", err)
+		return types.ActionContinue
+	}
+	boundary, ok := params["boundary"]
+	if !ok {
+		log.Errorf("no boundary in content type")
+		return types.ActionContinue
+	}
+
+	reader := multipart.NewReader(bytes.NewReader(body), boundary)
+	var newBody bytes.Buffer
+	writer := multipart.NewWriter(&newBody)
+	writer.SetBoundary(boundary)
+
+	modified := false
+
+	for {
+		part, err := reader.NextPart()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			log.Errorf("failed to read multipart part: %v", err)
+			return types.ActionContinue
+		}
+
+		// Read part content
+		partContent, err := io.ReadAll(part)
+		if err != nil {
+			log.Errorf("failed to read part content: %v", err)
+			return types.ActionContinue
+		}
+
+		formName := part.FormName()
+		if formName == config.modelKey {
+			modelValue := string(partContent)
+
+			if config.modelToHeader != "" {
+				_ = proxywasm.ReplaceHttpRequestHeader(config.modelToHeader, modelValue)
+			}
+
+			if config.addProviderHeader != "" {
+				parts := strings.SplitN(modelValue, "/", 2)
+				if len(parts) == 2 {
+					provider := parts[0]
+					model := parts[1]
+					_ = proxywasm.ReplaceHttpRequestHeader(config.addProviderHeader, provider)
+
+					// Write modified part
+					h := make(http.Header)
+					for k, v := range part.Header {
+						h[k] = v
+					}
+
+					pw, err := writer.CreatePart(textproto.MIMEHeader(h))
+					if err != nil {
+						log.Errorf("failed to create part: %v", err)
+						return types.ActionContinue
+					}
+					_, err = pw.Write([]byte(model))
+					if err != nil {
+						log.Errorf("failed to write part content: %v", err)
+						return types.ActionContinue
+					}
+					modified = true
+					log.Debugf("model route to provider: %s, model: %s", provider, model)
+					continue
+				} else {
+					log.Debugf("model route to provider not work, model: %s", modelValue)
+				}
+			}
+		}
+
+		// Write original part
+		h := make(http.Header)
+		for k, v := range part.Header {
+			h[k] = v
+		}
+		pw, err := writer.CreatePart(textproto.MIMEHeader(h))
+		if err != nil {
+			log.Errorf("failed to create part: %v", err)
+			return types.ActionContinue
+		}
+		_, err = pw.Write(partContent)
+		if err != nil {
+			log.Errorf("failed to write part content: %v", err)
+			return types.ActionContinue
+		}
+	}
+
+	writer.Close()
+
+	if modified {
+		_ = proxywasm.ReplaceHttpRequestBody(newBody.Bytes())
+	}
+
+	return types.ActionContinue
+}
--- a/plugins/wasm-go/extensions/model-router/main_test.go
+++ b/plugins/wasm-go/extensions/model-router/main_test.go
@@ -0,0 +1,288 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"mime/multipart"
+	"strings"
+	"testing"
+
+	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm/types"
+	"github.com/higress-group/wasm-go/pkg/test"
+	"github.com/stretchr/testify/require"
+	"github.com/tidwall/gjson"
+)
+
+// Basic configs for wasm test host
+var (
+	basicConfig = func() json.RawMessage {
+		data, _ := json.Marshal(map[string]interface{}{
+			"modelKey":          "model",
+			"addProviderHeader": "x-provider",
+			"modelToHeader":     "x-model",
+			"enableOnPathSuffix": []string{
+				"/v1/chat/completions",
+			},
+		})
+		return data
+	}()
+
+	defaultSuffixConfig = func() json.RawMessage {
+		data, _ := json.Marshal(map[string]interface{}{
+			"modelKey":          "model",
+			"addProviderHeader": "x-provider",
+			"modelToHeader":     "x-model",
+		})
+		return data
+	}()
+)
+
+func getHeader(headers [][2]string, key string) (string, bool) {
+	for _, h := range headers {
+		if strings.EqualFold(h[0], key) {
+			return h[1], true
+		}
+	}
+	return "", false
+}
+
+func TestParseConfig(t *testing.T) {
+	test.RunGoTest(t, func(t *testing.T) {
+		t.Run("basic config with defaults", func(t *testing.T) {
+			var cfg ModelRouterConfig
+			err := parseConfig(gjson.ParseBytes(defaultSuffixConfig), &cfg)
+			require.NoError(t, err)
+
+			// default modelKey
+			require.Equal(t, "model", cfg.modelKey)
+			// headers
+			require.Equal(t, "x-provider", cfg.addProviderHeader)
+			require.Equal(t, "x-model", cfg.modelToHeader)
+			// default enabled path suffixes should contain common openai paths
+			require.Contains(t, cfg.enableOnPathSuffix, "/completions")
+			require.Contains(t, cfg.enableOnPathSuffix, "/embeddings")
+		})
+
+		t.Run("custom enableOnPathSuffix", func(t *testing.T) {
+			jsonData := []byte(`{
+				"modelKey": "my_model",
+				"addProviderHeader": "x-prov",
+				"modelToHeader": "x-mod",
+				"enableOnPathSuffix": ["/foo", "/bar"]
+			}`)
+			var cfg ModelRouterConfig
+			err := parseConfig(gjson.ParseBytes(jsonData), &cfg)
+			require.NoError(t, err)
+
+			require.Equal(t, "my_model", cfg.modelKey)
+			require.Equal(t, "x-prov", cfg.addProviderHeader)
+			require.Equal(t, "x-mod", cfg.modelToHeader)
+			require.Equal(t, []string{"/foo", "/bar"}, cfg.enableOnPathSuffix)
+		})
+	})
+}
+
+func TestOnHttpRequestHeaders(t *testing.T) {
+	test.RunTest(t, func(t *testing.T) {
+		t.Run("skip when path not matched", func(t *testing.T) {
+			host, status := test.NewTestHost(basicConfig)
+			defer host.Reset()
+			require.Equal(t, types.OnPluginStartStatusOK, status)
+
+			originalHeaders := [][2]string{
+				{":authority", "example.com"},
+				{":path", "/v1/other"},
+				{":method", "POST"},
+				{"content-type", "application/json"},
+				{"content-length", "123"},
+			}
+			action := host.CallOnHttpRequestHeaders(originalHeaders)
+			require.Equal(t, types.ActionContinue, action)
+
+			newHeaders := host.GetRequestHeaders()
+			_, found := getHeader(newHeaders, "content-length")
+			require.True(t, found, "content-length should be kept when path not enabled")
+		})
+
+		t.Run("process when path and content-type match", func(t *testing.T) {
+			host, status := test.NewTestHost(basicConfig)
+			defer host.Reset()
+			require.Equal(t, types.OnPluginStartStatusOK, status)
+
+			originalHeaders := [][2]string{
+				{":authority", "example.com"},
+				{":path", "/v1/chat/completions"},
+				{":method", "POST"},
+				{"content-type", "application/json"},
+				{"content-length", "123"},
+			}
+			action := host.CallOnHttpRequestHeaders(originalHeaders)
+			require.Equal(t, types.HeaderStopIteration, action)
+
+			newHeaders := host.GetRequestHeaders()
+			_, found := getHeader(newHeaders, "content-length")
+			require.False(t, found, "content-length should be removed when buffering body")
+		})
+
+		t.Run("do not process for unsupported content-type", func(t *testing.T) {
+			host, status := test.NewTestHost(basicConfig)
+			defer host.Reset()
+			require.Equal(t, types.OnPluginStartStatusOK, status)
+
+			originalHeaders := [][2]string{
+				{":authority", "example.com"},
+				{":path", "/v1/chat/completions"},
+				{":method", "POST"},
+				{"content-type", "text/plain"},
+				{"content-length", "123"},
+			}
+			action := host.CallOnHttpRequestHeaders(originalHeaders)
+			require.Equal(t, types.HeaderStopIteration, action)
+
+			newHeaders := host.GetRequestHeaders()
+			_, found := getHeader(newHeaders, "content-length")
+			require.False(t, found, "content-length should not be removed for unsupported content-type")
+		})
+	})
+}
+
+func TestOnHttpRequestBody_JSON(t *testing.T) {
+	test.RunTest(t, func(t *testing.T) {
+		t.Run("set headers and rewrite model when provider/model format", func(t *testing.T) {
+			host, status := test.NewTestHost(basicConfig)
+			defer host.Reset()
+			require.Equal(t, types.OnPluginStartStatusOK, status)
+
+			host.CallOnHttpRequestHeaders([][2]string{
+				{":authority", "example.com"},
+				{":path", "/v1/chat/completions"},
+				{":method", "POST"},
+				{"content-type", "application/json"},
+			})
+
+			origBody := []byte(`{
+				"model": "openai/gpt-4o",
+				"messages": [{"role": "user", "content": "hello"}]
+			}`)
+			action := host.CallOnHttpRequestBody(origBody)
+			require.Equal(t, types.ActionContinue, action)
+
+			processed := host.GetRequestBody()
+			require.NotNil(t, processed)
+			// model should be rewritten to only the model part
+			require.Equal(t, "gpt-4o", gjson.GetBytes(processed, "model").String())
+
+			headers := host.GetRequestHeaders()
+			hv, found := getHeader(headers, "x-model")
+			require.True(t, found)
+			require.Equal(t, "openai/gpt-4o", hv)
+			pv, found := getHeader(headers, "x-provider")
+			require.True(t, found)
+			require.Equal(t, "openai", pv)
+		})
+
+		t.Run("no change when model not provided", func(t *testing.T) {
+			host, status := test.NewTestHost(basicConfig)
+			defer host.Reset()
+			require.Equal(t, types.OnPluginStartStatusOK, status)
+
+			host.CallOnHttpRequestHeaders([][2]string{
+				{":authority", "example.com"},
+				{":path", "/v1/chat/completions"},
+				{":method", "POST"},
+				{"content-type", "application/json"},
+			})
+
+			origBody := []byte(`{
+				"messages": [{"role": "user", "content": "hello"}]
+			}`)
+			action := host.CallOnHttpRequestBody(origBody)
+			require.Equal(t, types.ActionContinue, action)
+
+			processed := host.GetRequestBody()
+			// body should remain nil or unchanged as plugin does nothing
+			if processed != nil {
+				require.JSONEq(t, string(origBody), string(processed))
+			}
+			_, found := getHeader(host.GetRequestHeaders(), "x-provider")
+			require.False(t, found)
+		})
+	})
+}
+
+func TestOnHttpRequestBody_Multipart(t *testing.T) {
+	test.RunTest(t, func(t *testing.T) {
+		host, status := test.NewTestHost(basicConfig)
+		defer host.Reset()
+		require.Equal(t, types.OnPluginStartStatusOK, status)
+
+		var buf bytes.Buffer
+		writer := multipart.NewWriter(&buf)
+
+		// model field
+		modelWriter, err := writer.CreateFormField("model")
+		require.NoError(t, err)
+		_, err = modelWriter.Write([]byte("openai/gpt-4o"))
+		require.NoError(t, err)
+
+		// another field to ensure others are preserved
+		fileWriter, err := writer.CreateFormField("prompt")
+		require.NoError(t, err)
+		_, err = fileWriter.Write([]byte("hello"))
+		require.NoError(t, err)
+
+		err = writer.Close()
+		require.NoError(t, err)
+
+		contentType := "multipart/form-data; boundary=" + writer.Boundary()
+
+		host.CallOnHttpRequestHeaders([][2]string{
+			{":authority", "example.com"},
+			{":path", "/v1/chat/completions"},
+			{":method", "POST"},
+			{"content-type", contentType},
+		})
+
+		action := host.CallOnHttpRequestBody(buf.Bytes())
+		require.Equal(t, types.ActionContinue, action)
+
+		processed := host.GetRequestBody()
+		require.NotNil(t, processed)
+
+		// Parse multipart body again to verify fields
+		reader := multipart.NewReader(bytes.NewReader(processed), writer.Boundary())
+
+		foundModel := false
+		foundPrompt := false
+		for {
+			part, err := reader.NextPart()
+			if err != nil {
+				break
+			}
+			name := part.FormName()
+			data, err := io.ReadAll(part)
+			require.NoError(t, err)
+
+			switch name {
+			case "model":
+				foundModel = true
+				require.Equal(t, "gpt-4o", string(data))
+			case "prompt":
+				foundPrompt = true
+				require.Equal(t, "hello", string(data))
+			}
+		}
+
+		require.True(t, foundModel)
+		require.True(t, foundPrompt)
+
+		headers := host.GetRequestHeaders()
+		hv, found := getHeader(headers, "x-model")
+		require.True(t, found)
+		require.Equal(t, "openai/gpt-4o", hv)
+		pv, found := getHeader(headers, "x-provider")
+		require.True(t, found)
+		require.Equal(t, "openai", pv)
+	})
+}