MCP Toolbox for Databases

// Copyright 2025 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 clickhouse import ( "context" "database/sql" "fmt" yaml "github.com/goccy/go-yaml" "github.com/googleapis/genai-toolbox/internal/sources" "github.com/googleapis/genai-toolbox/internal/tools" "github.com/googleapis/genai-toolbox/internal/util/parameters" ) const listTablesKind string = "clickhouse-list-tables" const databaseKey string = "database" func init() { if !tools.Register(listTablesKind, newListTablesConfig) { panic(fmt.Sprintf("tool kind %q already registered", listTablesKind)) } } func newListTablesConfig(ctx context.Context, name string, decoder *yaml.Decoder) (tools.ToolConfig, error) { actual := Config{Name: name} if err := decoder.DecodeContext(ctx, &actual); err != nil { return nil, err } return actual, nil } type compatibleSource interface { ClickHousePool() *sql.DB } type Config struct { Name string `yaml:"name" validate:"required"` Kind string `yaml:"kind" validate:"required"` Source string `yaml:"source" validate:"required"` Description string `yaml:"description" validate:"required"` AuthRequired []string `yaml:"authRequired"` Parameters parameters.Parameters `yaml:"parameters"` } var _ tools.ToolConfig = Config{} func (cfg Config) ToolConfigKind() string { return listTablesKind } func (cfg Config) Initialize(srcs map[string]sources.Source) (tools.Tool, error) { databaseParameter := parameters.NewStringParameter(databaseKey, "The database to list tables from.") params := parameters.Parameters{databaseParameter} allParameters, paramManifest, _ := parameters.ProcessParameters(nil, params) mcpManifest := tools.GetMcpManifest(cfg.Name, cfg.Description, cfg.AuthRequired, allParameters, nil) t := Tool{ Config: cfg, AllParams: allParameters, manifest: tools.Manifest{Description: cfg.Description, Parameters: paramManifest, AuthRequired: cfg.AuthRequired}, mcpManifest: mcpManifest, } return t, nil } var _ tools.Tool = Tool{} type Tool struct { Config AllParams parameters.Parameters `yaml:"allParams"` manifest tools.Manifest mcpManifest tools.McpManifest } func (t Tool) ToConfig() tools.ToolConfig { return t.Config } func (t Tool) Invoke(ctx context.Context, resourceMgr tools.SourceProvider, params parameters.ParamValues, token tools.AccessToken) (any, error) { source, err := tools.GetCompatibleSource[compatibleSource](resourceMgr, t.Source, t.Name, t.Kind) if err != nil { return nil, err } mapParams := params.AsMap() database, ok := mapParams[databaseKey].(string) if !ok { return nil, fmt.Errorf("invalid or missing '%s' parameter; expected a string", databaseKey) } // Query to list all tables in the specified database query := fmt.Sprintf("SHOW TABLES FROM %s", database) results, err := source.ClickHousePool().QueryContext(ctx, query) if err != nil { return nil, fmt.Errorf("unable to execute query: %w", err) } defer results.Close() tables := []map[string]any{} for results.Next() { var tableName string err := results.Scan(&tableName) if err != nil { return nil, fmt.Errorf("unable to parse row: %w", err) } tables = append(tables, map[string]any{ "name": tableName, "database": database, }) } if err := results.Err(); err != nil { return nil, fmt.Errorf("errors encountered by results.Scan: %w", err) } return tables, nil } func (t Tool) ParseParams(data map[string]any, claims map[string]map[string]any) (parameters.ParamValues, error) { return parameters.ParseParams(t.AllParams, data, claims) } func (t Tool) Manifest() tools.Manifest { return t.manifest } func (t Tool) McpManifest() tools.McpManifest { return t.mcpManifest } func (t Tool) Authorized(verifiedAuthServices []string) bool { return tools.IsAuthorized(t.AuthRequired, verifiedAuthServices) } func (t Tool) RequiresClientAuthorization(resourceMgr tools.SourceProvider) (bool, error) { return false, nil } func (t Tool) GetAuthTokenHeaderName(resourceMgr tools.SourceProvider) (string, error) { return "Authorization", nil }