Merge branch 'main' into integration-test

cmd/root.go

@@ -33,6 +33,7 @@ import (
 	"github.com/fsnotify/fsnotify"
 	yaml "github.com/goccy/go-yaml"
 	"github.com/googleapis/genai-toolbox/internal/auth"
+	"github.com/googleapis/genai-toolbox/internal/embeddingmodels"
 	"github.com/googleapis/genai-toolbox/internal/log"
 	"github.com/googleapis/genai-toolbox/internal/prebuiltconfigs"
 	"github.com/googleapis/genai-toolbox/internal/prompts"
@@ -385,12 +386,13 @@ func NewCommand(opts ...Option) *Command {
 }
 
 type ToolsFile struct {
-	Sources      server.SourceConfigs      `yaml:"sources"`
-	AuthSources  server.AuthServiceConfigs `yaml:"authSources"` // Deprecated: Kept for compatibility.
-	AuthServices server.AuthServiceConfigs `yaml:"authServices"`
-	Tools        server.ToolConfigs        `yaml:"tools"`
-	Toolsets     server.ToolsetConfigs     `yaml:"toolsets"`
-	Prompts      server.PromptConfigs      `yaml:"prompts"`
+	Sources         server.SourceConfigs         `yaml:"sources"`
+	AuthSources     server.AuthServiceConfigs    `yaml:"authSources"` // Deprecated: Kept for compatibility.
+	AuthServices    server.AuthServiceConfigs    `yaml:"authServices"`
+	EmbeddingModels server.EmbeddingModelConfigs `yaml:"embeddingModels"`
+	Tools           server.ToolConfigs           `yaml:"tools"`
+	Toolsets        server.ToolsetConfigs        `yaml:"toolsets"`
+	Prompts         server.PromptConfigs         `yaml:"prompts"`
 }
 
 // parseEnv replaces environment variables ${ENV_NAME} with their values.
@@ -439,11 +441,12 @@ func parseToolsFile(ctx context.Context, raw []byte) (ToolsFile, error) {
 // All resource names (sources, authServices, tools, toolsets) must be unique across all files.
 func mergeToolsFiles(files ...ToolsFile) (ToolsFile, error) {
 	merged := ToolsFile{
-		Sources:      make(server.SourceConfigs),
-		AuthServices: make(server.AuthServiceConfigs),
-		Tools:        make(server.ToolConfigs),
-		Toolsets:     make(server.ToolsetConfigs),
-		Prompts:      make(server.PromptConfigs),
+		Sources:         make(server.SourceConfigs),
+		AuthServices:    make(server.AuthServiceConfigs),
+		EmbeddingModels: make(server.EmbeddingModelConfigs),
+		Tools:           make(server.ToolConfigs),
+		Toolsets:        make(server.ToolsetConfigs),
+		Prompts:         make(server.PromptConfigs),
 	}
 
 	var conflicts []string
@@ -479,6 +482,15 @@ func mergeToolsFiles(files ...ToolsFile) (ToolsFile, error) {
 			}
 		}
 
+		// Check for conflicts and merge embeddingModels
+		for name, model := range file.EmbeddingModels {
+			if _, exists := merged.EmbeddingModels[name]; exists {
+				conflicts = append(conflicts, fmt.Sprintf("embedding model '%s' (file #%d)", name, fileIndex+1))
+			} else {
+				merged.EmbeddingModels[name] = model
+			}
+		}
+
 		// Check for conflicts and merge tools
 		for name, tool := range file.Tools {
 			if _, exists := merged.Tools[name]; exists {
@@ -583,14 +595,14 @@ func handleDynamicReload(ctx context.Context, toolsFile ToolsFile, s *server.Ser
 		panic(err)
 	}
 
-	sourcesMap, authServicesMap, toolsMap, toolsetsMap, promptsMap, promptsetsMap, err := validateReloadEdits(ctx, toolsFile)
+	sourcesMap, authServicesMap, embeddingModelsMap, toolsMap, toolsetsMap, promptsMap, promptsetsMap, err := validateReloadEdits(ctx, toolsFile)
 	if err != nil {
 		errMsg := fmt.Errorf("unable to validate reloaded edits: %w", err)
 		logger.WarnContext(ctx, errMsg.Error())
 		return err
 	}
 
-	s.ResourceMgr.SetResources(sourcesMap, authServicesMap, toolsMap, toolsetsMap, promptsMap, promptsetsMap)
+	s.ResourceMgr.SetResources(sourcesMap, authServicesMap, embeddingModelsMap, toolsMap, toolsetsMap, promptsMap, promptsetsMap)
 
 	return nil
 }
@@ -598,7 +610,7 @@ func handleDynamicReload(ctx context.Context, toolsFile ToolsFile, s *server.Ser
 // validateReloadEdits checks that the reloaded tools file configs can initialized without failing
 func validateReloadEdits(
 	ctx context.Context, toolsFile ToolsFile,
-) (map[string]sources.Source, map[string]auth.AuthService, map[string]tools.Tool, map[string]tools.Toolset, map[string]prompts.Prompt, map[string]prompts.Promptset, error,
+) (map[string]sources.Source, map[string]auth.AuthService, map[string]embeddingmodels.EmbeddingModel, map[string]tools.Tool, map[string]tools.Toolset, map[string]prompts.Prompt, map[string]prompts.Promptset, error,
 ) {
 	logger, err := util.LoggerFromContext(ctx)
 	if err != nil {
@@ -616,22 +628,23 @@ func validateReloadEdits(
 	defer span.End()
 
 	reloadedConfig := server.ServerConfig{
-		Version:            versionString,
-		SourceConfigs:      toolsFile.Sources,
-		AuthServiceConfigs: toolsFile.AuthServices,
-		ToolConfigs:        toolsFile.Tools,
-		ToolsetConfigs:     toolsFile.Toolsets,
-		PromptConfigs:      toolsFile.Prompts,
+		Version:               versionString,
+		SourceConfigs:         toolsFile.Sources,
+		AuthServiceConfigs:    toolsFile.AuthServices,
+		EmbeddingModelConfigs: toolsFile.EmbeddingModels,
+		ToolConfigs:           toolsFile.Tools,
+		ToolsetConfigs:        toolsFile.Toolsets,
+		PromptConfigs:         toolsFile.Prompts,
 	}
 
-	sourcesMap, authServicesMap, toolsMap, toolsetsMap, promptsMap, promptsetsMap, err := server.InitializeConfigs(ctx, reloadedConfig)
+	sourcesMap, authServicesMap, embeddingModelsMap, toolsMap, toolsetsMap, promptsMap, promptsetsMap, err := server.InitializeConfigs(ctx, reloadedConfig)
 	if err != nil {
 		errMsg := fmt.Errorf("unable to initialize reloaded configs: %w", err)
 		logger.WarnContext(ctx, errMsg.Error())
-		return nil, nil, nil, nil, nil, nil, err
+		return nil, nil, nil, nil, nil, nil, nil, err
 	}
 
-	return sourcesMap, authServicesMap, toolsMap, toolsetsMap, promptsMap, promptsetsMap, nil
+	return sourcesMap, authServicesMap, embeddingModelsMap, toolsMap, toolsetsMap, promptsMap, promptsetsMap, nil
 }
 
 // watchChanges checks for changes in the provided yaml tools file(s) or folder.

cmd/root_test.go

@@ -32,6 +32,7 @@ import (
 	"github.com/google/go-cmp/cmp"
 
 	"github.com/googleapis/genai-toolbox/internal/auth/google"
+	"github.com/googleapis/genai-toolbox/internal/embeddingmodels/gemini"
 	"github.com/googleapis/genai-toolbox/internal/log"
 	"github.com/googleapis/genai-toolbox/internal/prebuiltconfigs"
 	"github.com/googleapis/genai-toolbox/internal/prompts"
@@ -1830,9 +1831,10 @@ func TestFileLoadingErrors(t *testing.T) {
 
 func TestMergeToolsFiles(t *testing.T) {
 	file1 := ToolsFile{
-		Sources:  server.SourceConfigs{"source1": httpsrc.Config{Name: "source1"}},
-		Tools:    server.ToolConfigs{"tool1": http.Config{Name: "tool1"}},
-		Toolsets: server.ToolsetConfigs{"set1": tools.ToolsetConfig{Name: "set1"}},
+		Sources:         server.SourceConfigs{"source1": httpsrc.Config{Name: "source1"}},
+		Tools:           server.ToolConfigs{"tool1": http.Config{Name: "tool1"}},
+		Toolsets:        server.ToolsetConfigs{"set1": tools.ToolsetConfig{Name: "set1"}},
+		EmbeddingModels: server.EmbeddingModelConfigs{"model1": gemini.Config{Name: "gemini-text"}},
 	}
 	file2 := ToolsFile{
 		AuthServices: server.AuthServiceConfigs{"auth1": google.Config{Name: "auth1"}},
@@ -1854,11 +1856,12 @@ func TestMergeToolsFiles(t *testing.T) {
 			name:  "merge two distinct files",
 			files: []ToolsFile{file1, file2},
 			want: ToolsFile{
-				Sources:      server.SourceConfigs{"source1": httpsrc.Config{Name: "source1"}},
-				AuthServices: server.AuthServiceConfigs{"auth1": google.Config{Name: "auth1"}},
-				Tools:        server.ToolConfigs{"tool1": http.Config{Name: "tool1"}, "tool2": http.Config{Name: "tool2"}},
-				Toolsets:     server.ToolsetConfigs{"set1": tools.ToolsetConfig{Name: "set1"}, "set2": tools.ToolsetConfig{Name: "set2"}},
-				Prompts:      server.PromptConfigs{},
+				Sources:         server.SourceConfigs{"source1": httpsrc.Config{Name: "source1"}},
+				AuthServices:    server.AuthServiceConfigs{"auth1": google.Config{Name: "auth1"}},
+				Tools:           server.ToolConfigs{"tool1": http.Config{Name: "tool1"}, "tool2": http.Config{Name: "tool2"}},
+				Toolsets:        server.ToolsetConfigs{"set1": tools.ToolsetConfig{Name: "set1"}, "set2": tools.ToolsetConfig{Name: "set2"}},
+				Prompts:         server.PromptConfigs{},
+				EmbeddingModels: server.EmbeddingModelConfigs{"model1": gemini.Config{Name: "gemini-text"}},
 			},
 			wantErr: false,
 		},
@@ -1871,22 +1874,24 @@ func TestMergeToolsFiles(t *testing.T) {
 			name:  "merge single file",
 			files: []ToolsFile{file1},
 			want: ToolsFile{
-				Sources:      file1.Sources,
-				AuthServices: make(server.AuthServiceConfigs),
-				Tools:        file1.Tools,
-				Toolsets:     file1.Toolsets,
-				Prompts:      server.PromptConfigs{},
+				Sources:         file1.Sources,
+				AuthServices:    make(server.AuthServiceConfigs),
+				EmbeddingModels: server.EmbeddingModelConfigs{"model1": gemini.Config{Name: "gemini-text"}},
+				Tools:           file1.Tools,
+				Toolsets:        file1.Toolsets,
+				Prompts:         server.PromptConfigs{},
 			},
 		},
 		{
 			name:  "merge empty list",
 			files: []ToolsFile{},
 			want: ToolsFile{
-				Sources:      make(server.SourceConfigs),
-				AuthServices: make(server.AuthServiceConfigs),
-				Tools:        make(server.ToolConfigs),
-				Toolsets:     make(server.ToolsetConfigs),
-				Prompts:      server.PromptConfigs{},
+				Sources:         make(server.SourceConfigs),
+				AuthServices:    make(server.AuthServiceConfigs),
+				EmbeddingModels: make(server.EmbeddingModelConfigs),
+				Tools:           make(server.ToolConfigs),
+				Toolsets:        make(server.ToolsetConfigs),
+				Prompts:         server.PromptConfigs{},
 			},
 		},
 	}

docs/en/resources/embeddingModels/_index.md

@@ -0,0 +1,84 @@
+---
+title: "EmbeddingModels"
+type: docs
+weight: 2
+description: >
+  EmbeddingModels represent services that transform text into vector embeddings for semantic search.
+---
+
+EmbeddingModels represent services that generate vector representations of text
+data. In the MCP Toolbox, these models enable **Semantic Queries**,
+allowing [Tools](../tools/) to automatically convert human-readable text into
+numerical vectors before using them in a query.
+
+This is primarily used in two scenarios:
+
+- **Vector Ingestion**: Converting a text parameter into a vector string during
+  an `INSERT` operation.
+
+- **Semantic Search**: Converting a natural language query into a vector to
+  perform similarity searches.
+
+## Example
+
+The following configuration defines an embedding model and applies it to
+specific tool parameters.
+
+{{< notice tip >}}
+Use environment variable replacement with the format ${ENV_NAME}
+instead of hardcoding your API keys into the configuration file.
+{{< /notice >}}
+
+### Step 1 - Define an Embedding Model
+
+Define an embedding model in the `embeddingModels` section:
+
+```yaml
+embeddingModels:
+  gemini-model: # Name of the embedding model
+    kind: gemini
+    model: gemini-embedding-001
+    apiKey: ${GOOGLE_API_KEY}
+    dimension: 768
+
+```
+
+### Step 2 - Embed Tool Parameters
+
+Use the defined embedding model, embed your query parameters using the
+`embeddedBy` field. Only string-typed
+parameters can be embedded:
+
+```yaml
+tools:
+  # Vector ingestion tool
+  insert_embedding:
+    kind: postgres-sql
+    source: my-pg-instance
+    statement: |
+      INSERT INTO documents (content, embedding) 
+      VALUES ($1, $2);
+    parameters:
+      - name: content
+        type: string
+      - name: vector_string
+        type: string
+        description: The text to be vectorized and stored.
+        embeddedBy: gemini-model # refers to the name of a defined embedding model
+
+  # Semantic search tool
+  search_embedding:
+    kind: postgres-sql
+    source: my-pg-instance
+    statement: |
+      SELECT id, content, embedding <-> $1 AS distance 
+      FROM documents
+      ORDER BY distance LIMIT 1
+    parameters:
+      - name: semantic_search_string
+        type: string
+        description: The search query that will be converted to a vector.
+        embeddedBy: gemini-model # refers to the name of a defined embedding model
+```
+
+## Kinds of Embedding Models

docs/en/resources/embeddingModels/gemini.md

@@ -0,0 +1,73 @@
+---
+title: "Gemini Embedding"
+type: docs
+weight: 1
+description: >
+  Use Google's Gemini models to generate high-performance text embeddings for vector databases.
+---
+
+## About
+
+Google Gemini provides state-of-the-art embedding models that convert text into
+high-dimensional vectors. 
+
+### Authentication
+
+Toolbox uses your [Application Default Credentials
+(ADC)][adc] to authorize with the
+Gemini API client.
+
+Optionally, you can use an [API key][api-key] obtain an API
+Key from the [Google AI Studio][ai-studio].
+
+We recommend using an API key for testing and using application default
+credentials for production.
+
+[adc]: https://cloud.google.com/docs/authentication#adc
+[api-key]: https://ai.google.dev/gemini-api/docs/api-key#api-keys
+[ai-studio]: https://aistudio.google.com/app/apikey
+
+## Behavior
+
+### Automatic Vectorization
+
+When a tool parameter is configured with `embeddedBy: <your-gemini-model-name>`,
+the Toolbox intercepts the raw text input from the client and sends it to the
+Gemini API. The resulting numerical array is then formatted before being passed
+to your database source.
+
+### Dimension Matching
+
+The `dimension` field must match the expected size of your database column
+(e.g., a `vector(768)` column in PostgreSQL). This setting is supported by newer
+models since 2024 only. You cannot set this value if using the earlier model
+(`models/embedding-001`). Check out [available Gemini models][modellist] for more
+information.
+
+[modellist]:
+    https://docs.cloud.google.com/vertex-ai/generative-ai/docs/embeddings/get-text-embeddings#supported-models
+
+## Example
+
+```yaml
+embeddingModels:
+  gemini-model:
+    kind: gemini
+    model: gemini-embedding-001
+    apiKey: ${GOOGLE_API_KEY}
+    dimension: 768
+```
+
+{{< notice tip >}}
+Use environment variable replacement with the format ${ENV_NAME}
+instead of hardcoding your secrets into the configuration file.
+{{< /notice >}}
+
+## Reference
+
+| **field** | **type** | **required** | **description**                                              |
+|-----------|:--------:|:------------:|--------------------------------------------------------------|
+| kind      |  string  |     true     | Must be `gemini`.                                            |
+| model     |  string  |     true     | The Gemini model ID to use (e.g., `gemini-embedding-001`).   |
+| apiKey    |  string  |    false     | Your API Key from Google AI Studio.                          |
+| dimension | integer  |    false     | The number of dimensions in the output vector (e.g., `768`). |

go.mod

@@ -59,6 +59,7 @@ require (
 	go.opentelemetry.io/otel/trace v1.38.0
 	golang.org/x/oauth2 v0.33.0
 	google.golang.org/api v0.256.0
+	google.golang.org/genai v1.37.0
 	google.golang.org/genproto v0.0.0-20251022142026-3a174f9686a8
 	google.golang.org/protobuf v1.36.10
 	modernc.org/sqlite v1.40.0

go.sum

@@ -1869,6 +1869,8 @@ google.golang.org/appengine v1.6.1/go.mod h1:i06prIuMbXzDqacNJfV5OdTW448YApPu5ww
 google.golang.org/appengine v1.6.5/go.mod h1:8WjMMxjGQR8xUklV/ARdw2HLXBOI7O7uCIDZVag1xfc=
 google.golang.org/appengine v1.6.6/go.mod h1:8WjMMxjGQR8xUklV/ARdw2HLXBOI7O7uCIDZVag1xfc=
 google.golang.org/appengine v1.6.7/go.mod h1:8WjMMxjGQR8xUklV/ARdw2HLXBOI7O7uCIDZVag1xfc=
+google.golang.org/genai v1.37.0 h1:dgp71k1wQ+/+APdZrN3LFgAGnVnr5IdTF1Oj0Dg+BQc=
+google.golang.org/genai v1.37.0/go.mod h1:A3kkl0nyBjyFlNjgxIwKq70julKbIxpSxqKO5gw/gmk=
 google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
 google.golang.org/genproto v0.0.0-20190307195333-5fe7a883aa19/go.mod h1:VzzqZJRnGkLBvHegQrXjBqPurQTc5/KpmUdxsrq26oE=
 google.golang.org/genproto v0.0.0-20190418145605-e7d98fc518a7/go.mod h1:VzzqZJRnGkLBvHegQrXjBqPurQTc5/KpmUdxsrq26oE=

internal/embeddingmodels/embeddingmodels.go

@@ -0,0 +1,29 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package embeddingmodels
+
+import "context"
+
+// EmbeddingModelConfig is the interface for configuring embedding models.
+type EmbeddingModelConfig interface {
+	EmbeddingModelConfigKind() string
+	Initialize(context.Context) (EmbeddingModel, error)
+}
+
+type EmbeddingModel interface {
+	EmbeddingModelKind() string
+	ToConfig() EmbeddingModelConfig
+	EmbedParameters(context.Context, []string) ([][]float32, error)
+}

internal/embeddingmodels/gemini/gemini.go

@@ -0,0 +1,122 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package gemini
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/googleapis/genai-toolbox/internal/embeddingmodels"
+	"github.com/googleapis/genai-toolbox/internal/util"
+	"google.golang.org/genai"
+)
+
+const EmbeddingModelKind string = "gemini"
+
+// validate interface
+var _ embeddingmodels.EmbeddingModelConfig = Config{}
+
+type Config struct {
+	Name      string `yaml:"name" validate:"required"`
+	Kind      string `yaml:"kind" validate:"required"`
+	Model     string `yaml:"model" validate:"required"`
+	ApiKey    string `yaml:"apiKey"`
+	Dimension int32  `yaml:"dimension"`
+}
+
+// Returns the embedding model kind
+func (cfg Config) EmbeddingModelConfigKind() string {
+	return EmbeddingModelKind
+}
+
+// Initialize a Gemini embedding model
+func (cfg Config) Initialize(ctx context.Context) (embeddingmodels.EmbeddingModel, error) {
+	// Get client configs
+	configs := &genai.ClientConfig{}
+	if cfg.ApiKey != "" {
+		configs.APIKey = cfg.ApiKey
+	}
+
+	// Create new Gemini API client
+	client, err := genai.NewClient(ctx, configs)
+	if err != nil {
+		return nil, fmt.Errorf("unable to create Gemini API client")
+	}
+
+	m := &EmbeddingModel{
+		Config: cfg,
+		Client: client,
+	}
+	return m, nil
+}
+
+var _ embeddingmodels.EmbeddingModel = EmbeddingModel{}
+
+type EmbeddingModel struct {
+	Client *genai.Client
+	Config
+}
+
+// Returns the embedding model kind
+func (m EmbeddingModel) EmbeddingModelKind() string {
+	return EmbeddingModelKind
+}
+
+func (m EmbeddingModel) ToConfig() embeddingmodels.EmbeddingModelConfig {
+	return m.Config
+}
+
+func (m EmbeddingModel) EmbedParameters(ctx context.Context, parameters []string) ([][]float32, error) {
+	logger, err := util.LoggerFromContext(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("unable to get logger from ctx: %s", err)
+	}
+
+	contents := convertStringsToContents(parameters)
+
+	embedConfig := &genai.EmbedContentConfig{
+		TaskType: "SEMANTIC_SIMILARITY",
+	}
+
+	if m.Dimension > 0 {
+		embedConfig.OutputDimensionality = genai.Ptr(m.Dimension)
+	}
+
+	result, err := m.Client.Models.EmbedContent(ctx, m.Model, contents, embedConfig)
+	if err != nil {
+		logger.ErrorContext(ctx, "Error calling EmbedContent for model %s: %v", m.Model, err)
+		return nil, err
+	}
+
+	embeddings := make([][]float32, 0, len(result.Embeddings))
+	for _, embedding := range result.Embeddings {
+		embeddings = append(embeddings, embedding.Values)
+	}
+
+	logger.InfoContext(ctx, "Successfully embedded %d text parameters using model %s", len(parameters), m.Model)
+
+	return embeddings, nil
+}
+
+// convertStringsToContents takes a slice of strings and converts it into a slice of *genai.Content objects.
+func convertStringsToContents(texts []string) []*genai.Content {
+	contents := make([]*genai.Content, 0, len(texts))
+
+	for _, text := range texts {
+		content := genai.NewContentFromText(text, "")
+		contents = append(contents, content)
+	}
+	return contents
+}

internal/embeddingmodels/gemini/gemini_test.go

@@ -0,0 +1,130 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package gemini_test
+
+import (
+	"testing"
+
+	yaml "github.com/goccy/go-yaml"
+	"github.com/google/go-cmp/cmp"
+	"github.com/googleapis/genai-toolbox/internal/embeddingmodels"
+	"github.com/googleapis/genai-toolbox/internal/embeddingmodels/gemini"
+	"github.com/googleapis/genai-toolbox/internal/server"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
+)
+
+func TestParseFromYamlGemini(t *testing.T) {
+	tcs := []struct {
+		desc string
+		in   string
+		want server.EmbeddingModelConfigs
+	}{
+		{
+			desc: "basic example",
+			in: `
+            embeddingModels:
+                my-gemini-model:
+                    kind: gemini
+                    model: text-embedding-004
+            `,
+			want: map[string]embeddingmodels.EmbeddingModelConfig{
+				"my-gemini-model": gemini.Config{
+					Name:  "my-gemini-model",
+					Kind:  gemini.EmbeddingModelKind,
+					Model: "text-embedding-004",
+				},
+			},
+		},
+		{
+			desc: "full example with optional fields",
+			in: `
+            embeddingModels:
+                complex-gemini:
+                    kind: gemini
+                    model: text-embedding-004
+                    apiKey: "test-api-key"
+                    dimension: 768
+            `,
+			want: map[string]embeddingmodels.EmbeddingModelConfig{
+				"complex-gemini": gemini.Config{
+					Name:      "complex-gemini",
+					Kind:      gemini.EmbeddingModelKind,
+					Model:     "text-embedding-004",
+					ApiKey:    "test-api-key",
+					Dimension: 768,
+				},
+			},
+		},
+	}
+	for _, tc := range tcs {
+		t.Run(tc.desc, func(t *testing.T) {
+			got := struct {
+				Models server.EmbeddingModelConfigs `yaml:"embeddingModels"`
+			}{}
+			// Parse contents
+			err := yaml.Unmarshal(testutils.FormatYaml(tc.in), &got)
+			if err != nil {
+				t.Fatalf("unable to unmarshal: %s", err)
+			}
+			if !cmp.Equal(tc.want, got.Models) {
+				t.Fatalf("incorrect parse: %v", cmp.Diff(tc.want, got.Models))
+			}
+		})
+	}
+}
+func TestFailParseFromYamlGemini(t *testing.T) {
+	tcs := []struct {
+		desc string
+		in   string
+		err  string
+	}{
+		{
+			desc: "missing required model field",
+			in: `
+            embeddingModels:
+                bad-model:
+                    kind: gemini
+            `,
+			// Removed the specific model name from the prefix to match your output
+			err: "unable to parse as \"gemini\": Key: 'Config.Model' Error:Field validation for 'Model' failed on the 'required' tag",
+		},
+		{
+			desc: "unknown field",
+			in: `
+            embeddingModels:
+                bad-field:
+                    kind: gemini
+                    model: text-embedding-004
+                    invalid_param: true
+            `,
+			// Updated to match the specific line-starting format of your error output
+			err: "unable to parse as \"gemini\": [1:1] unknown field \"invalid_param\"\n>  1 | invalid_param: true\n       ^\n   2 | kind: gemini\n   3 | model: text-embedding-004",
+		},
+	}
+	for _, tc := range tcs {
+		t.Run(tc.desc, func(t *testing.T) {
+			got := struct {
+				Models server.EmbeddingModelConfigs `yaml:"embeddingModels"`
+			}{}
+			err := yaml.Unmarshal(testutils.FormatYaml(tc.in), &got)
+			if err == nil {
+				t.Fatalf("expect parsing to fail")
+			}
+			if err.Error() != tc.err {
+				t.Fatalf("unexpected error:\ngot:  %q\nwant: %q", err.Error(), tc.err)
+			}
+		})
+	}
+}

internal/prebuiltconfigs/tools/cloud-sql-mysql.yaml

@@ -19,8 +19,8 @@ sources:
     region: ${CLOUD_SQL_MYSQL_REGION}
     instance: ${CLOUD_SQL_MYSQL_INSTANCE}
     database: ${CLOUD_SQL_MYSQL_DATABASE}
-    user: ${CLOUD_SQL_MYSQL_USER}
-    password: ${CLOUD_SQL_MYSQL_PASSWORD}
+    user: ${CLOUD_SQL_MYSQL_USER:}
+    password: ${CLOUD_SQL_MYSQL_PASSWORD:}
     ipType: ${CLOUD_SQL_MYSQL_IP_TYPE:PUBLIC}
 tools:
   execute_sql:

internal/server/common_test.go

@@ -276,7 +276,7 @@ func setUpServer(t *testing.T, router string, tools map[string]tools.Tool, tools
 
 	sseManager := newSseManager(ctx)
 
-	resourceManager := resources.NewResourceManager(nil, nil, tools, toolsets, prompts, promptsets)
+	resourceManager := resources.NewResourceManager(nil, nil, nil, tools, toolsets, prompts, promptsets)
 
 	server := Server{
 		version:         fakeVersionString,

internal/server/config.go

@@ -21,6 +21,8 @@ import (
 	yaml "github.com/goccy/go-yaml"
 	"github.com/googleapis/genai-toolbox/internal/auth"
 	"github.com/googleapis/genai-toolbox/internal/auth/google"
+	"github.com/googleapis/genai-toolbox/internal/embeddingmodels"
+	"github.com/googleapis/genai-toolbox/internal/embeddingmodels/gemini"
 	"github.com/googleapis/genai-toolbox/internal/prompts"
 	"github.com/googleapis/genai-toolbox/internal/sources"
 	"github.com/googleapis/genai-toolbox/internal/tools"
@@ -38,6 +40,8 @@ type ServerConfig struct {
 	SourceConfigs SourceConfigs
 	// AuthServiceConfigs defines what sources of authentication are available for tools.
 	AuthServiceConfigs AuthServiceConfigs
+	// EmbeddingModelConfigs defines a models used to embed parameters.
+	EmbeddingModelConfigs EmbeddingModelConfigs
 	// ToolConfigs defines what tools are available.
 	ToolConfigs ToolConfigs
 	// ToolsetConfigs defines what tools are available.
@@ -205,6 +209,50 @@ func (c *AuthServiceConfigs) UnmarshalYAML(ctx context.Context, unmarshal func(i
 	return nil
 }
 
+// EmbeddingModelConfigs is a type used to allow unmarshal of the embedding model config map
+type EmbeddingModelConfigs map[string]embeddingmodels.EmbeddingModelConfig
+
+// validate interface
+var _ yaml.InterfaceUnmarshalerContext = &EmbeddingModelConfigs{}
+
+func (c *EmbeddingModelConfigs) UnmarshalYAML(ctx context.Context, unmarshal func(interface{}) error) error {
+	*c = make(EmbeddingModelConfigs)
+	// Parse the 'kind' fields for each embedding model
+	var raw map[string]util.DelayedUnmarshaler
+	if err := unmarshal(&raw); err != nil {
+		return err
+	}
+
+	for name, u := range raw {
+		// Unmarshal to a general type that ensure it capture all fields
+		var v map[string]any
+		if err := u.Unmarshal(&v); err != nil {
+			return fmt.Errorf("unable to unmarshal embedding model %q: %w", name, err)
+		}
+
+		kind, ok := v["kind"]
+		if !ok {
+			return fmt.Errorf("missing 'kind' field for embedding model %q", name)
+		}
+
+		dec, err := util.NewStrictDecoder(v)
+		if err != nil {
+			return fmt.Errorf("error creating decoder: %w", err)
+		}
+		switch kind {
+		case gemini.EmbeddingModelKind:
+			actual := gemini.Config{Name: name}
+			if err := dec.DecodeContext(ctx, &actual); err != nil {
+				return fmt.Errorf("unable to parse as %q: %w", kind, err)
+			}
+			(*c)[name] = actual
+		default:
+			return fmt.Errorf("%q is not a valid kind of auth source", kind)
+		}
+	}
+	return nil
+}
+
 // ToolConfigs is a type used to allow unmarshal of the tool configs
 type ToolConfigs map[string]tools.ToolConfig
 

internal/server/mcp_test.go

@@ -1107,7 +1107,7 @@ func TestStdioSession(t *testing.T) {
 
 	sseManager := newSseManager(ctx)
 
-	resourceManager := resources.NewResourceManager(nil, nil, toolsMap, toolsets, promptsMap, promptsets)
+	resourceManager := resources.NewResourceManager(nil, nil, nil, toolsMap, toolsets, promptsMap, promptsets)
 
 	server := &Server{
 		version:         fakeVersionString,

internal/server/resources/resources.go

@@ -18,6 +18,7 @@ import (
 	"sync"
 
 	"github.com/googleapis/genai-toolbox/internal/auth"
+	"github.com/googleapis/genai-toolbox/internal/embeddingmodels"
 	"github.com/googleapis/genai-toolbox/internal/prompts"
 	"github.com/googleapis/genai-toolbox/internal/sources"
 	"github.com/googleapis/genai-toolbox/internal/tools"
@@ -25,30 +26,33 @@ import (
 
 // ResourceManager contains available resources for the server. Should be initialized with NewResourceManager().
 type ResourceManager struct {
-	mu           sync.RWMutex
-	sources      map[string]sources.Source
-	authServices map[string]auth.AuthService
-	tools        map[string]tools.Tool
-	toolsets     map[string]tools.Toolset
-	prompts      map[string]prompts.Prompt
-	promptsets   map[string]prompts.Promptset
+	mu              sync.RWMutex
+	sources         map[string]sources.Source
+	authServices    map[string]auth.AuthService
+	embeddingModels map[string]embeddingmodels.EmbeddingModel
+	tools           map[string]tools.Tool
+	toolsets        map[string]tools.Toolset
+	prompts         map[string]prompts.Prompt
+	promptsets      map[string]prompts.Promptset
 }
 
 func NewResourceManager(
 	sourcesMap map[string]sources.Source,
 	authServicesMap map[string]auth.AuthService,
+	embeddingModelsMap map[string]embeddingmodels.EmbeddingModel,
 	toolsMap map[string]tools.Tool, toolsetsMap map[string]tools.Toolset,
 	promptsMap map[string]prompts.Prompt, promptsetsMap map[string]prompts.Promptset,
 
 ) *ResourceManager {
 	resourceMgr := &ResourceManager{
-		mu:           sync.RWMutex{},
-		sources:      sourcesMap,
-		authServices: authServicesMap,
-		tools:        toolsMap,
-		toolsets:     toolsetsMap,
-		prompts:      promptsMap,
-		promptsets:   promptsetsMap,
+		mu:              sync.RWMutex{},
+		sources:         sourcesMap,
+		authServices:    authServicesMap,
+		embeddingModels: embeddingModelsMap,
+		tools:           toolsMap,
+		toolsets:        toolsetsMap,
+		prompts:         promptsMap,
+		promptsets:      promptsetsMap,
 	}
 
 	return resourceMgr
@@ -68,6 +72,13 @@ func (r *ResourceManager) GetAuthService(authServiceName string) (auth.AuthServi
 	return authService, ok
 }
 
+func (r *ResourceManager) GetEmbeddingModel(embeddingModelName string) (embeddingmodels.EmbeddingModel, bool) {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	model, ok := r.embeddingModels[embeddingModelName]
+	return model, ok
+}
+
 func (r *ResourceManager) GetTool(toolName string) (tools.Tool, bool) {
 	r.mu.RLock()
 	defer r.mu.RUnlock()
@@ -96,11 +107,12 @@ func (r *ResourceManager) GetPromptset(promptsetName string) (prompts.Promptset,
 	return promptset, ok
 }
 
-func (r *ResourceManager) SetResources(sourcesMap map[string]sources.Source, authServicesMap map[string]auth.AuthService, toolsMap map[string]tools.Tool, toolsetsMap map[string]tools.Toolset, promptsMap map[string]prompts.Prompt, promptsetsMap map[string]prompts.Promptset) {
+func (r *ResourceManager) SetResources(sourcesMap map[string]sources.Source, authServicesMap map[string]auth.AuthService, embeddingModelsMap map[string]embeddingmodels.EmbeddingModel, toolsMap map[string]tools.Tool, toolsetsMap map[string]tools.Toolset, promptsMap map[string]prompts.Prompt, promptsetsMap map[string]prompts.Promptset) {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 	r.sources = sourcesMap
 	r.authServices = authServicesMap
+	r.embeddingModels = embeddingModelsMap
 	r.tools = toolsMap
 	r.toolsets = toolsetsMap
 	r.prompts = promptsMap
@@ -117,6 +129,16 @@ func (r *ResourceManager) GetAuthServiceMap() map[string]auth.AuthService {
 	return copiedMap
 }
 
+func (r *ResourceManager) GetEmbeddingModelMap() map[string]embeddingmodels.EmbeddingModel {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	copiedMap := make(map[string]embeddingmodels.EmbeddingModel, len(r.embeddingModels))
+	for k, v := range r.embeddingModels {
+		copiedMap[k] = v
+	}
+	return copiedMap
+}
+
 func (r *ResourceManager) GetToolsMap() map[string]tools.Tool {
 	r.mu.RLock()
 	defer r.mu.RUnlock()

internal/server/resources/resources_test.go

@@ -19,6 +19,7 @@ import (
 
 	"github.com/google/go-cmp/cmp"
 	"github.com/googleapis/genai-toolbox/internal/auth"
+	"github.com/googleapis/genai-toolbox/internal/embeddingmodels"
 	"github.com/googleapis/genai-toolbox/internal/prompts"
 	"github.com/googleapis/genai-toolbox/internal/server/resources"
 	"github.com/googleapis/genai-toolbox/internal/sources"
@@ -36,6 +37,7 @@ func TestUpdateServer(t *testing.T) {
 		},
 	}
 	newAuth := map[string]auth.AuthService{"example-auth": nil}
+	newEmbeddingModels := map[string]embeddingmodels.EmbeddingModel{"example-model": nil}
 	newTools := map[string]tools.Tool{"example-tool": nil}
 	newToolsets := map[string]tools.Toolset{
 		"example-toolset": {
@@ -54,7 +56,7 @@ func TestUpdateServer(t *testing.T) {
 			Prompts: []*prompts.Prompt{},
 		},
 	}
-	resMgr := resources.NewResourceManager(newSources, newAuth, newTools, newToolsets, newPrompts, newPromptsets)
+	resMgr := resources.NewResourceManager(newSources, newAuth, newEmbeddingModels, newTools, newToolsets, newPrompts, newPromptsets)
 
 	gotSource, _ := resMgr.GetSource("example-source")
 	if diff := cmp.Diff(gotSource, newSources["example-source"]); diff != "" {
@@ -95,7 +97,7 @@ func TestUpdateServer(t *testing.T) {
 		},
 	}
 
-	resMgr.SetResources(updateSource, newAuth, newTools, newToolsets, newPrompts, newPromptsets)
+	resMgr.SetResources(updateSource, newAuth, newEmbeddingModels, newTools, newToolsets, newPrompts, newPromptsets)
 	gotSource, _ = resMgr.GetSource("example-source2")
 	if diff := cmp.Diff(gotSource, updateSource["example-source2"]); diff != "" {
 		t.Errorf("error updating server, sources (-want +got):\n%s", diff)

internal/server/server.go

@@ -30,6 +30,7 @@ import (
 	"github.com/go-chi/cors"
 	"github.com/go-chi/httplog/v2"
 	"github.com/googleapis/genai-toolbox/internal/auth"
+	"github.com/googleapis/genai-toolbox/internal/embeddingmodels"
 	"github.com/googleapis/genai-toolbox/internal/log"
 	"github.com/googleapis/genai-toolbox/internal/prompts"
 	"github.com/googleapis/genai-toolbox/internal/server/resources"
@@ -56,6 +57,7 @@ type Server struct {
 func InitializeConfigs(ctx context.Context, cfg ServerConfig) (
 	map[string]sources.Source,
 	map[string]auth.AuthService,
+	map[string]embeddingmodels.EmbeddingModel,
 	map[string]tools.Tool,
 	map[string]tools.Toolset,
 	map[string]prompts.Prompt,
@@ -91,7 +93,7 @@ func InitializeConfigs(ctx context.Context, cfg ServerConfig) (
 			return s, nil
 		}()
 		if err != nil {
-			return nil, nil, nil, nil, nil, nil, err
+			return nil, nil, nil, nil, nil, nil, nil, err
 		}
 		sourcesMap[name] = s
 	}
@@ -119,7 +121,7 @@ func InitializeConfigs(ctx context.Context, cfg ServerConfig) (
 			return a, nil
 		}()
 		if err != nil {
-			return nil, nil, nil, nil, nil, nil, err
+			return nil, nil, nil, nil, nil, nil, nil, err
 		}
 		authServicesMap[name] = a
 	}
@@ -129,6 +131,34 @@ func InitializeConfigs(ctx context.Context, cfg ServerConfig) (
 	}
 	l.InfoContext(ctx, fmt.Sprintf("Initialized %d authServices: %s", len(authServicesMap), strings.Join(authServiceNames, ", ")))
 
+	// Initialize and validate embedding models from configs.
+	embeddingModelsMap := make(map[string]embeddingmodels.EmbeddingModel)
+	for name, ec := range cfg.EmbeddingModelConfigs {
+		em, err := func() (embeddingmodels.EmbeddingModel, error) {
+			_, span := instrumentation.Tracer.Start(
+				ctx,
+				"toolbox/server/embeddingmodel/init",
+				trace.WithAttributes(attribute.String("model_kind", ec.EmbeddingModelConfigKind())),
+				trace.WithAttributes(attribute.String("model_name", name)),
+			)
+			defer span.End()
+			em, err := ec.Initialize(ctx)
+			if err != nil {
+				return nil, fmt.Errorf("unable to initialize embedding model %q: %w", name, err)
+			}
+			return em, nil
+		}()
+		if err != nil {
+			return nil, nil, nil, nil, nil, nil, nil, err
+		}
+		embeddingModelsMap[name] = em
+	}
+	embeddingModelNames := make([]string, 0, len(embeddingModelsMap))
+	for name := range embeddingModelsMap {
+		embeddingModelNames = append(embeddingModelNames, name)
+	}
+	l.InfoContext(ctx, fmt.Sprintf("Initialized %d embeddingModels: %s", len(embeddingModelsMap), strings.Join(embeddingModelNames, ", ")))
+
 	// initialize and validate the tools from configs
 	toolsMap := make(map[string]tools.Tool)
 	for name, tc := range cfg.ToolConfigs {
@@ -147,7 +177,7 @@ func InitializeConfigs(ctx context.Context, cfg ServerConfig) (
 			return t, nil
 		}()
 		if err != nil {
-			return nil, nil, nil, nil, nil, nil, err
+			return nil, nil, nil, nil, nil, nil, nil, err
 		}
 		toolsMap[name] = t
 	}
@@ -184,7 +214,7 @@ func InitializeConfigs(ctx context.Context, cfg ServerConfig) (
 			return t, err
 		}()
 		if err != nil {
-			return nil, nil, nil, nil, nil, nil, err
+			return nil, nil, nil, nil, nil, nil, nil, err
 		}
 		toolsetsMap[name] = t
 	}
@@ -216,7 +246,7 @@ func InitializeConfigs(ctx context.Context, cfg ServerConfig) (
 			return p, nil
 		}()
 		if err != nil {
-			return nil, nil, nil, nil, nil, nil, err
+			return nil, nil, nil, nil, nil, nil, nil, err
 		}
 		promptsMap[name] = p
 	}
@@ -253,7 +283,7 @@ func InitializeConfigs(ctx context.Context, cfg ServerConfig) (
 			return p, err
 		}()
 		if err != nil {
-			return nil, nil, nil, nil, nil, nil, err
+			return nil, nil, nil, nil, nil, nil, nil, err
 		}
 		promptsetsMap[name] = p
 	}
@@ -267,7 +297,7 @@ func InitializeConfigs(ctx context.Context, cfg ServerConfig) (
 	}
 	l.InfoContext(ctx, fmt.Sprintf("Initialized %d promptsets: %s", len(promptsetsMap), strings.Join(promptsetNames, ", ")))
 
-	return sourcesMap, authServicesMap, toolsMap, toolsetsMap, promptsMap, promptsetsMap, nil
+	return sourcesMap, authServicesMap, embeddingModelsMap, toolsMap, toolsetsMap, promptsMap, promptsetsMap, nil
 }
 
 // NewServer returns a Server object based on provided Config.
@@ -320,7 +350,7 @@ func NewServer(ctx context.Context, cfg ServerConfig) (*Server, error) {
 	httpLogger := httplog.NewLogger("httplog", httpOpts)
 	r.Use(httplog.RequestLogger(httpLogger))
 
-	sourcesMap, authServicesMap, toolsMap, toolsetsMap, promptsMap, promptsetsMap, err := InitializeConfigs(ctx, cfg)
+	sourcesMap, authServicesMap, embeddingModelsMap, toolsMap, toolsetsMap, promptsMap, promptsetsMap, err := InitializeConfigs(ctx, cfg)
 	if err != nil {
 		return nil, fmt.Errorf("unable to initialize configs: %w", err)
 	}
@@ -330,7 +360,7 @@ func NewServer(ctx context.Context, cfg ServerConfig) (*Server, error) {
 
 	sseManager := newSseManager(ctx)
 
-	resourceManager := resources.NewResourceManager(sourcesMap, authServicesMap, toolsMap, toolsetsMap, promptsMap, promptsetsMap)
+	resourceManager := resources.NewResourceManager(sourcesMap, authServicesMap, embeddingModelsMap, toolsMap, toolsetsMap, promptsMap, promptsetsMap)
 
 	s := &Server{
 		version:         cfg.Version,

internal/server/server_test.go

@@ -25,6 +25,7 @@ import (
 
 	"github.com/google/go-cmp/cmp"
 	"github.com/googleapis/genai-toolbox/internal/auth"
+	"github.com/googleapis/genai-toolbox/internal/embeddingmodels"
 	"github.com/googleapis/genai-toolbox/internal/log"
 	"github.com/googleapis/genai-toolbox/internal/prompts"
 	"github.com/googleapis/genai-toolbox/internal/server"
@@ -144,6 +145,7 @@ func TestUpdateServer(t *testing.T) {
 		},
 	}
 	newAuth := map[string]auth.AuthService{"example-auth": nil}
+	newEmbeddingModels := map[string]embeddingmodels.EmbeddingModel{"example-model": nil}
 	newTools := map[string]tools.Tool{"example-tool": nil}
 	newToolsets := map[string]tools.Toolset{
 		"example-toolset": {
@@ -162,7 +164,7 @@ func TestUpdateServer(t *testing.T) {
 			Prompts: []*prompts.Prompt{},
 		},
 	}
-	s.ResourceMgr.SetResources(newSources, newAuth, newTools, newToolsets, newPrompts, newPromptsets)
+	s.ResourceMgr.SetResources(newSources, newAuth, newEmbeddingModels, newTools, newToolsets, newPrompts, newPromptsets)
 	if err != nil {
 		t.Errorf("error updating server: %s", err)
 	}

internal/tools/cloudgda/cloudgda_test.go

@@ -333,7 +333,7 @@ func TestInvoke(t *testing.T) {
 		{Name: "prompt", Value: "How many accounts who have region in Prague are eligible for loans?"},
 	}
 
-	resourceMgr := resources.NewResourceManager(srcs, nil, nil, nil, nil, nil)
+	resourceMgr := resources.NewResourceManager(srcs, nil, nil, nil, nil, nil, nil)
 
 	// Invoke the tool
 	result, err := tool.Invoke(ctx, resourceMgr, params, "") // No accessToken needed for ADC client