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 fhirfetchpage import ( "context" "encoding/json" "fmt" "io" "github.com/goccy/go-yaml" "github.com/googleapis/genai-toolbox/internal/sources" healthcareds "github.com/googleapis/genai-toolbox/internal/sources/cloudhealthcare" "github.com/googleapis/genai-toolbox/internal/tools" "github.com/googleapis/genai-toolbox/internal/util/parameters" "google.golang.org/api/healthcare/v1" "net/http" "golang.org/x/oauth2" "golang.org/x/oauth2/google" ) const kind string = "cloud-healthcare-fhir-fetch-page" const ( pageURLKey = "pageURL" ) 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 { Project() string Region() string DatasetID() string AllowedFHIRStores() map[string]struct{} Service() *healthcare.Service ServiceCreator() healthcareds.HealthcareServiceCreator UseClientAuthorization() bool } 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"` } // 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) { urlParameter := parameters.NewStringParameter(pageURLKey, "The full URL of the FHIR page to fetch. This would be the value of `Bundle.entry.link.url` field within the response returned from FHIR search or FHIR patient everything operations.") params := parameters.Parameters{urlParameter} mcpManifest := tools.GetMcpManifest(cfg.Name, cfg.Description, cfg.AuthRequired, params, nil) // finish tool setup t := Tool{ Config: cfg, Parameters: params, manifest: tools.Manifest{Description: cfg.Description, Parameters: params.Manifest(), AuthRequired: cfg.AuthRequired}, mcpManifest: mcpManifest, } return t, nil } // validate interface var _ tools.Tool = Tool{} type Tool struct { Config Parameters parameters.Parameters `yaml:"parameters"` 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 } url, ok := params.AsMap()[pageURLKey].(string) if !ok { return nil, fmt.Errorf("invalid or missing '%s' parameter; expected a string", pageURLKey) } var httpClient *http.Client if source.UseClientAuthorization() { tokenStr, err := accessToken.ParseBearerToken() if err != nil { return nil, fmt.Errorf("error parsing access token: %w", err) } ts := oauth2.StaticTokenSource(&oauth2.Token{AccessToken: tokenStr}) httpClient = oauth2.NewClient(ctx, ts) } else { // The source.Service() object holds a client with the default credentials. // However, the client is not exported, so we have to create a new one. var err error httpClient, err = google.DefaultClient(ctx, healthcare.CloudHealthcareScope) if err != nil { return nil, fmt.Errorf("failed to create default http client: %w", err) } } req, err := http.NewRequestWithContext(ctx, "GET", url, nil) if err != nil { return nil, fmt.Errorf("failed to create http request: %w", err) } req.Header.Set("Accept", "application/fhir+json;charset=utf-8") resp, err := httpClient.Do(req) if err != nil { return nil, fmt.Errorf("failed to get fhir page from %q: %w", url, err) } defer resp.Body.Close() respBytes, err := io.ReadAll(resp.Body) if err != nil { return nil, fmt.Errorf("could not read response: %w", err) } if resp.StatusCode > 299 { return nil, fmt.Errorf("read: status %d %s: %s", resp.StatusCode, resp.Status, respBytes) } var jsonMap map[string]interface{} if err := json.Unmarshal([]byte(string(respBytes)), &jsonMap); err != nil { return nil, fmt.Errorf("could not unmarshal response as json: %w", err) } return jsonMap, nil } func (t Tool) ParseParams(data map[string]any, claims map[string]map[string]any) (parameters.ParamValues, error) { return parameters.ParseParams(t.Parameters, 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) { source, err := tools.GetCompatibleSource[compatibleSource](resourceMgr, t.Source, t.Name, t.Kind) if err != nil { return false, err } return source.UseClientAuthorization(), nil } func (t Tool) GetAuthTokenHeaderName(resourceMgr tools.SourceProvider) (string, error) { return "Authorization", nil }