experimental-ext-interceptors/go/sdk/interceptors/wire.go
Ukjae Jeong 23d889254b
Go SDK: Align hooks with SEP (#23)
The SEP spec and C# SDK use hooks (plural, JSON array) but the Go SDK
had hook (singular, single object). This meant the wire formats were
incompatible — Go would send `{"hook": {...}}` while everything else
expects `{"hooks": [...]}`.

Signed-off-by: Ukjae Jeong <jeongukjae@gmail.com>
2026-06-16 15:49:49 +01:00

106 lines
3.4 KiB
Go

// Copyright 2025 The MCP Interceptors Authors. All rights reserved.
// Use of this source code is governed by an Apache-2.0
// license that can be found in the LICENSE file.
package interceptors
import (
"encoding/json"
"github.com/modelcontextprotocol/go-sdk/mcp"
)
// JSON-RPC method names for the interceptor protocol.
const (
MethodList = "interceptors/list"
MethodInvoke = "interceptor/invoke"
)
// Event name constants for standard MCP methods.
const (
// Server Features
EventToolsList = "tools/list"
EventToolsCall = "tools/call"
EventPromptsList = "prompts/list"
EventPromptsGet = "prompts/get"
EventResourcesList = "resources/list"
EventResourcesRead = "resources/read"
EventResourcesSubscribe = "resources/subscribe"
)
// --- interceptors/list ---
// ListParams are the optional parameters for the interceptors/list method.
type ListParams struct {
mcp.ParamsBase
Event string `json:"event,omitempty"` // Filter by event name; empty = all
}
// InterceptorInfo describes a registered interceptor in wire format.
type InterceptorInfo struct {
Name string `json:"name"`
Version string `json:"version,omitempty"`
Description string `json:"description,omitempty"`
Type InterceptorType `json:"type"`
Hooks []Hook `json:"hooks"`
PriorityHint Priority `json:"priorityHint,omitempty"`
Compat *Compat `json:"compat,omitempty"`
ConfigSchema json.RawMessage `json:"configSchema,omitempty"`
Mode Mode `json:"mode"`
FailOpen bool `json:"failOpen,omitempty"`
}
// InfoFromInterceptor builds an InterceptorInfo from an Interceptor.
func InfoFromInterceptor(i Interceptor) InterceptorInfo {
m := i.GetMetadata()
return InterceptorInfo{
Name: m.Name,
Version: m.Version,
Description: m.Description,
Type: i.GetType(),
Hooks: m.Hooks,
PriorityHint: m.PriorityHint,
Compat: m.Compat,
ConfigSchema: m.ConfigSchema,
Mode: m.Mode,
FailOpen: m.FailOpen,
}
}
// ListResult is the result of the interceptors/list method.
type ListResult struct {
mcp.ResultBase
Interceptors []InterceptorInfo `json:"interceptors"`
}
// --- interceptor/invoke ---
// InvokeParams are the parameters for the interceptor/invoke method.
// The caller specifies which interceptor to invoke by name.
type InvokeParams struct {
mcp.ParamsBase
Name string `json:"name"`
Event string `json:"event"`
Phase InterceptionPhase `json:"phase"`
Payload json.RawMessage `json:"payload"`
TimeoutMs int64 `json:"timeoutMs,omitempty"`
Config map[string]any `json:"config,omitempty"`
Context *InvocationContext `json:"context,omitempty"`
}
// InvokeResult is the result of the interceptor/invoke method.
// Fields are type-specific: validators populate Validation, mutators populate Mutation + Payload.
type InvokeResult struct {
mcp.ResultBase
Interceptor string `json:"interceptor"`
Type InterceptorType `json:"type"`
Phase InterceptionPhase `json:"phase"`
DurationMs int64 `json:"durationMs"`
// Validation result (type == "validation")
Validation *ValidationResult `json:"validation,omitempty"`
// Mutation result (type == "mutation")
Mutation *MutationResult `json:"mutation,omitempty"`
Payload json.RawMessage `json:"payload,omitempty"` // Mutated payload (only for mutators)
}