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 postgreslistindexes 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-indexes" const listIndexesStatement = ` WITH IndexDetails AS ( SELECT s.schemaname AS schema_name, t.relname AS table_name, i.relname AS index_name, am.amname AS index_type, ix.indisunique AS is_unique, ix.indisprimary AS is_primary, pg_get_indexdef(i.oid) AS index_definition, pg_relation_size(i.oid) AS index_size_bytes, s.idx_scan AS index_scans, s.idx_tup_read AS tuples_read, s.idx_tup_fetch AS tuples_fetched, CASE WHEN s.idx_scan > 0 THEN true ELSE false END AS is_used FROM pg_catalog.pg_class t JOIN pg_catalog.pg_index ix ON t.oid = ix.indrelid JOIN pg_catalog.pg_class i ON i.oid = ix.indexrelid JOIN pg_catalog.pg_am am ON i.relam = am.oid JOIN pg_catalog.pg_stat_all_indexes s ON i.oid = s.indexrelid WHERE t.relkind = 'r' AND s.schemaname NOT IN ('pg_catalog', 'information_schema', 'pg_toast') AND s.schemaname NOT LIKE 'pg_temp_%' ) SELECT * FROM IndexDetails WHERE ($1::text IS NULL OR schema_name LIKE '%' || $1 || '%') AND ($2::text IS NULL OR table_name LIKE '%' || $2 || '%') AND ($3::text IS NULL OR index_name LIKE '%' || $3 || '%') AND ($4::boolean IS NOT TRUE OR is_used IS FALSE) ORDER BY schema_name, table_name, index_name LIMIT COALESCE($5::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("schema_name", "", "Optional: a text to filter results by schema name. The input is used within a LIKE clause."), parameters.NewStringParameterWithDefault("table_name", "", "Optional: a text to filter results by table name. The input is used within a LIKE clause."), parameters.NewStringParameterWithDefault("index_name", "", "Optional: a text to filter results by index name. The input is used within a LIKE clause."), parameters.NewBooleanParameterWithDefault("only_unused", false, "Optional: If true, only returns indexes that have never been used."), parameters.NewIntParameterWithDefault("limit", 50, "Optional: The maximum number of rows to return. Default is 50"), } if cfg.Description == "" { cfg.Description = "Lists available user indexes in the database, excluding system schemas (pg_catalog, information_schema). For each index, the following properties are returned: schema name, table name, index name, index type (access method), a boolean indicating if it's a unique index, a boolean indicating if it's for a primary key, the index definition, index size in bytes, the number of index scans, the number of index tuples read, the number of table tuples fetched via index scans, and a boolean indicating if the index has been used at least once." } 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: allParameters.Manifest(), 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) ToConfig() tools.ToolConfig { return t.Config } 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, listIndexesStatement, 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) GetAuthTokenHeaderName(resourceMgr tools.SourceProvider) (string, error) { return "Authorization", nil }