feat: add MCP endpoint exposing calendar tools over Streamable HTTP

Adds a POST /mcp endpoint (github.com/modelcontextprotocol/go-sdk) with three tools mirroring the existing /calendar logic: get_calendar_today, get_calendar_for_date and get_holidays. Bumps go.mod to Go 1.25 (required by the SDK) and vendors the new dependencies. Also fixes an unanchored .gitignore rule ("domogeek") that was silently excluding all untracked files under cmd/domogeek/. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Hu8wwahgecuCGfesTKCfEd
2026-09-05 10:53:31 +02:00
parent e30c25b198
commit e5468ef654
553 changed files with 88442 additions and 12995 deletions
@@ -0,0 +1,194 @@
+// Copyright 2025 The Go MCP SDK Authors. All rights reserved.
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+package mcp
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"github.com/google/jsonschema-go/jsonschema"
+	internaljson "github.com/modelcontextprotocol/go-sdk/internal/json"
+)
+
+// A ToolHandler handles a call to tools/call.
+//
+// This is a low-level API, for use with [Server.AddTool]. It does not do any
+// pre- or post-processing of the request or result: the params contain raw
+// arguments, no input validation is performed, and the result is returned to
+// the user as-is, without any validation of the output.
+//
+// Most users will write a [ToolHandlerFor] and install it with the generic
+// [AddTool] function.
+//
+// If ToolHandler returns an error, it is treated as a protocol error. By
+// contrast, [ToolHandlerFor] automatically populates [CallToolResult.IsError]
+// and [CallToolResult.Content] accordingly.
+type ToolHandler func(context.Context, *CallToolRequest) (*CallToolResult, error)
+
+// A ToolHandlerFor handles a call to tools/call with typed arguments and results.
+//
+// Use [AddTool] to add a ToolHandlerFor to a server.
+//
+// Unlike [ToolHandler], [ToolHandlerFor] provides significant functionality
+// out of the box, and enforces that the tool conforms to the MCP spec:
+//   - The In type provides a default input schema for the tool, though it may
+//     be overridden in [AddTool].
+//   - The input value is automatically unmarshaled from req.Params.Arguments.
+//   - The input value is automatically validated against its input schema.
+//     Invalid input is rejected before getting to the handler.
+//   - If the Out type is not the empty interface [any], it provides the
+//     default output schema for the tool (which again may be overridden in
+//     [AddTool]).
+//   - The Out value is used to populate result.StructuredOutput.
+//   - If [CallToolResult.Content] is unset, it is populated with the JSON
+//     content of the output.
+//   - An error result is treated as a tool error, rather than a protocol
+//     error, and is therefore packed into CallToolResult.Content, with
+//     [IsError] set.
+//
+// For these reasons, most users can ignore the [CallToolRequest] argument and
+// [CallToolResult] return values entirely. In fact, it is permissible to
+// return a nil CallToolResult, if you only care about returning a output value
+// or error. The effective result will be populated as described above.
+type ToolHandlerFor[In, Out any] func(_ context.Context, request *CallToolRequest, input In) (result *CallToolResult, output Out, _ error)
+
+// A serverTool is a tool definition that is bound to a tool handler.
+type serverTool struct {
+	tool    *Tool
+	handler ToolHandler
+}
+
+// applySchema validates whether data is valid JSON according to the provided
+// schema, after applying schema defaults.
+//
+// If forOutput is false, the data is treated as tool input: the schema's root
+// type must be "object" and the value is unmarshaled into a map.
+//
+// If forOutput is true, the data is treated as tool output: the schema's root
+// may be of any type (object, array, primitive, composition).
+//
+// Returns the JSON value, augmented with defaults where applicable.
+func applySchema(data json.RawMessage, resolved *jsonschema.Resolved, forOutput bool) (json.RawMessage, error) {
+	// TODO: use reflection to create the struct type to unmarshal into.
+	// Separate validation from assignment.
+
+	// Use default JSON marshalling for validation.
+	//
+	// This avoids inconsistent representation due to custom marshallers, such as
+	// time.Time (issue #449).
+	//
+	// For input, unmarshalling into a map ensures that the resulting JSON is
+	// at least {}, even if data is empty. For example, arguments is technically
+	// an optional property of callToolParams, and we still want to apply the
+	// defaults in this case.
+	//
+	// TODO(rfindley): in which cases can resolved be nil?
+	if resolved == nil {
+		return data, nil
+	}
+
+	var unmarshaled any
+	if !forOutput {
+		v := make(map[string]any)
+		if len(data) > 0 {
+			if err := internaljson.Unmarshal(data, &v); err != nil {
+				return nil, fmt.Errorf("unmarshaling arguments: %w", err)
+			}
+		}
+		unmarshaled = v
+	} else {
+		if len(data) > 0 {
+			if err := internaljson.Unmarshal(data, &unmarshaled); err != nil {
+				return nil, fmt.Errorf("unmarshaling output: %w", err)
+			}
+		}
+	}
+
+	// Apply defaults only when the value is a map: jsonschema.Resolved.ApplyDefaults
+	// only operates on object properties. For object-rooted output schemas,
+	// coerce a nil result (from "null" or empty data) into {} so handlers that
+	// return a typed-nil map still validate.
+	appliedDefaults := false
+	if _, ok := unmarshaled.(map[string]any); ok {
+		if err := resolved.ApplyDefaults(&unmarshaled); err != nil {
+			return nil, fmt.Errorf("applying schema defaults:\n%w", err)
+		}
+		appliedDefaults = true
+	} else if forOutput && unmarshaled == nil && resolved.Schema().Type == "object" {
+		unmarshaled = make(map[string]any)
+		if err := resolved.ApplyDefaults(&unmarshaled); err != nil {
+			return nil, fmt.Errorf("applying schema defaults:\n%w", err)
+		}
+		appliedDefaults = true
+	}
+
+	if err := resolved.Validate(&unmarshaled); err != nil {
+		return nil, err
+	}
+
+	// Re-marshal only when defaults may have changed the value.
+	if !appliedDefaults {
+		return data, nil
+	}
+	out, err := json.Marshal(unmarshaled)
+	if err != nil {
+		return nil, fmt.Errorf("marshalling with defaults: %v", err)
+	}
+	return out, nil
+}
+
+// isObjectJSON reports whether data is a JSON object (i.e., starts with '{'
+// after any leading whitespace). Returns false for arrays, primitives, null,
+// or empty input.
+func isObjectJSON(data json.RawMessage) bool {
+	for _, b := range data {
+		switch b {
+		case ' ', '\t', '\n', '\r':
+			continue
+		case '{':
+			return true
+		default:
+			return false
+		}
+	}
+	return false
+}
+
+// validateToolName checks whether name is a valid tool name, reporting a
+// non-nil error if not.
+func validateToolName(name string) error {
+	if name == "" {
+		return fmt.Errorf("tool name cannot be empty")
+	}
+	if len(name) > 128 {
+		return fmt.Errorf("tool name exceeds maximum length of 128 characters (current: %d)", len(name))
+	}
+	// For consistency with other SDKs, report characters in the order the appear
+	// in the name.
+	var invalidChars []string
+	seen := make(map[rune]bool)
+	for _, r := range name {
+		if !validToolNameRune(r) {
+			if !seen[r] {
+				invalidChars = append(invalidChars, fmt.Sprintf("%q", string(r)))
+				seen[r] = true
+			}
+		}
+	}
+	if len(invalidChars) > 0 {
+		return fmt.Errorf("tool name contains invalid characters: %s", strings.Join(invalidChars, ", "))
+	}
+	return nil
+}
+
+// validToolNameRune reports whether r is valid within tool names.
+func validToolNameRune(r rune) bool {
+	return (r >= 'a' && r <= 'z') ||
+		(r >= 'A' && r <= 'Z') ||
+		(r >= '0' && r <= '9') ||
+		r == '_' || r == '-' || r == '.'
+}