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 postgreslisttablestats 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-table-stats" const listTableStats = ` WITH table_stats AS ( SELECT s.schemaname AS schema_name, s.relname AS table_name, pg_catalog.pg_get_userbyid(c.relowner) AS owner, pg_total_relation_size(s.relid) AS total_size_bytes, s.seq_scan, s.idx_scan, -- Ratio of index scans to total scans CASE WHEN (s.seq_scan + s.idx_scan) = 0 THEN 0 ELSE round((s.idx_scan * 100.0) / (s.seq_scan + s.idx_scan), 2) END AS idx_scan_ratio_percent, s.n_live_tup AS live_rows, s.n_dead_tup AS dead_rows, -- Percentage of rows that are "dead" (bloat) CASE WHEN (s.n_live_tup + s.n_dead_tup) = 0 THEN 0 ELSE round((s.n_dead_tup * 100.0) / (s.n_live_tup + s.n_dead_tup), 2) END AS dead_row_ratio_percent, s.n_tup_ins, s.n_tup_upd, s.n_tup_del, s.last_vacuum, s.last_autovacuum, s.last_autoanalyze FROM pg_stat_all_tables s JOIN pg_catalog.pg_class c ON s.relid = c.oid ) SELECT * FROM table_stats WHERE ($1::text IS NULL OR schema_name LIKE '%' || $1::text || '%') AND ($2::text IS NULL OR table_name LIKE '%' || $2::text || '%') AND ($3::text IS NULL OR owner LIKE '%' || $3::text || '%') ORDER BY CASE WHEN $4::text = 'size' THEN total_size_bytes WHEN $4::text = 'dead_rows' THEN dead_rows WHEN $4::text = 'seq_scan' THEN seq_scan WHEN $4::text = 'idx_scan' THEN idx_scan ELSE seq_scan END DESC 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", "public", "Optional: A specific schema name to filter by"), parameters.NewStringParameterWithRequired("table_name", "Optional: A specific table name to filter by", false), parameters.NewStringParameterWithRequired("owner", "Optional: A specific owner to filter by", false), parameters.NewStringParameterWithRequired("sort_by", "Optional: The column to sort by", false), parameters.NewIntParameterWithDefault("limit", 50, "Optional: The maximum number of results to return"), } paramManifest := allParameters.Manifest() if cfg.Description == "" { cfg.Description = `Lists the user table statistics in the database ordered by number of sequential scans with a default limit of 50 rows. Returns the following columns: schema name, table name, table size in bytes, number of sequential scans, number of index scans, idx_scan_ratio_percent (showing the percentage of total scans that utilized an index, where a low ratio indicates missing or ineffective indexes), number of live rows, number of dead rows, dead_row_ratio_percent (indicating potential table bloat), total number of rows inserted, updated, and deleted, the timestamps for the last_vacuum, last_autovacuum, and last_autoanalyze operations.` } 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) 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, listTableStats, 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) } 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 }