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 postgreslistviews import ( "context" "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" "github.com/jackc/pgx/v5/pgxpool" ) const kind string = "postgres-list-views" const listViewsStatement = ` WITH list_views AS ( SELECT schemaname AS schema_name, viewname AS view_name, viewowner AS owner_name, definition FROM pg_views ) SELECT * FROM list_views WHERE schema_name NOT IN ('pg_catalog', 'information_schema', 'pg_toast') AND schema_name NOT LIKE 'pg_temp_%' AND ($1::text IS NULL OR view_name ILIKE '%' || $1::text || '%') AND ($2::text IS NULL OR schema_name ILIKE '%' || $2::text || '%') ORDER BY schema_name, view_name LIMIT COALESCE($3::int, 50); ` func init() { if !tools.Register(kind, newConfig) { panic(fmt.Sprintf("tool kind %q already registered", kind)) } } func newConfig(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 { PostgresPool() *pgxpool.Pool } 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"` AuthRequired []string `yaml:"authRequired"` } // validate interface var _ tools.ToolConfig = Config{} func (cfg Config) ToolConfigKind() string { return kind } func (cfg Config) Initialize(srcs map[string]sources.Source) (tools.Tool, error) { allParameters := parameters.Parameters{ parameters.NewStringParameterWithDefault("view_name", "", "Optional: A specific view name to search for."), parameters.NewStringParameterWithDefault("schema_name", "", "Optional: A specific schema name to search for."), parameters.NewIntParameterWithDefault("limit", 50, "Optional: The maximum number of rows to return."), } paramManifest := allParameters.Manifest() if cfg.Description == "" { cfg.Description = "Lists views in the database from pg_views with a default limit of 50 rows. Returns schemaname, viewname, ownername and the definition." } mcpManifest := tools.GetMcpManifest(cfg.Name, cfg.Description, cfg.AuthRequired, allParameters, nil) // finish tool setup return Tool{ Config: cfg, allParams: allParameters, manifest: tools.Manifest{ Description: cfg.Description, Parameters: paramManifest, AuthRequired: cfg.AuthRequired, }, mcpManifest: mcpManifest, }, nil } // validate interface var _ tools.Tool = Tool{} type Tool struct { Config allParams parameters.Parameters `yaml:"allParams"` manifest tools.Manifest mcpManifest tools.McpManifest } func (t Tool) Invoke(ctx context.Context, resourceMgr tools.SourceProvider, params parameters.ParamValues, accessToken tools.AccessToken) (any, error) { source, err := tools.GetCompatibleSource[compatibleSource](resourceMgr, t.Source, t.Name, t.Kind) if err != nil { return nil, err } paramsMap := params.AsMap() newParams, err := parameters.GetParams(t.allParams, paramsMap) if err != nil { return nil, fmt.Errorf("unable to extract standard params %w", err) } sliceParams := newParams.AsSlice() results, err := source.PostgresPool().Query(ctx, listViewsStatement, sliceParams...) if err != nil { return nil, fmt.Errorf("unable to execute query: %w", err) } defer results.Close() fields := results.FieldDescriptions() var out []map[string]any for results.Next() { values, err := results.Values() if err != nil { return nil, fmt.Errorf("unable to parse row: %w", err) } rowMap := make(map[string]any) for i, field := range fields { rowMap[string(field.Name)] = values[i] } out = append(out, rowMap) } // this will catch actual query execution errors if err := results.Err(); err != nil { return nil, fmt.Errorf("unable to execute query: %w", err) } return out, 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) ToConfig() tools.ToolConfig { return t.Config } func (t Tool) GetAuthTokenHeaderName(resourceMgr tools.SourceProvider) (string, error) { return "Authorization", nil }