mcp

package
v1.4.0 Latest Latest
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 Go to latest Published: Oct 9, 2025 License: Apache-2.0 Imports: 21 Imported by: 0

Documentation

Overview

Package mcp implements Dynamic Client Registration Protocol (RFC 7591)

Package mcp provides a client for the Model Control Protocol (MCP) that allows the AI plugin to access external tools provided by MCP servers.

The UserClients represents a single user's connection to multiple MCP servers. The Client represents a connection to a single MCP server. The UserClients currently only supports authentication via Mattermost user ID header X-Mattermost-UserID. In the future it will support our OAuth implementation.

The ClientManager manages multiple UserClients, allowing for efficient mangement of connections. It is responsible for creating and closing UserClients as needed.

The organization reflects the need for each user to have their own connection to the MCP server given the design of MCP.

Index

Constants

View Source 
const MMUserIDHeader = "X-Mattermost-UserID"

Variables

This section is empty.

Functions

func GetRegistrationEndpoint added in v1.4.0 

func GetRegistrationEndpoint(ctx context.Context, httpClient *http.Client, serverURL string) (string, error)

GetRegistrationEndpoint discovers the registration endpoint from server metadata

Types

type AuthorizationServerMetadata added in v1.4.0 

type AuthorizationServerMetadata struct {
	Issuer                 string   `json:"issuer"`
	AuthorizationEndpoint  string   `json:"authorization_endpoint"`
	TokenEndpoint          string   `json:"token_endpoint"`
	ResponseTypesSupported []string `json:"response_types_supported"`
	GrantTypesSupported    []string `json:"grant_types_supported,omitempty"`
	ScopesSupported        []string `json:"scopes_supported,omitempty"`
	RegistrationEndpoint   string   `json:"registration_endpoint,omitempty"`
}

AuthorizationServerMetadata represents the OAuth 2.0 Authorization Server Metadata (RFC 8414)

type Client added in v1.4.0 

type Client struct {
	// contains filtered or unexported fields
}

Client represents the connection to a single MCP server

func NewClient added in v1.4.0 

func NewClient(ctx context.Context, userID string, serverConfig ServerConfig, log pluginapi.LogService, oauthManager *OAuthManager) (*Client, error)

NewClient creates a new MCP client for the given server and user and connects to the specified MCP server

func (*Client) CallTool added in v1.4.0 

func (c *Client) CallTool(ctx context.Context, toolName string, args map[string]any) (string, error)

CallTool calls a tool on this MCP server

func (*Client) Close added in v1.4.0 

func (c *Client) Close() error

Close closes the connection to the MCP server

func (*Client) Tools added in v1.4.0 

func (c *Client) Tools() map[string]*mcp.Tool

Tools returns the tools available from this client

type ClientCredentials added in v1.4.0 

type ClientCredentials struct {
	ClientID     string    `json:"clientID"`
	ClientSecret string    `json:"clientSecret"`
	ServerURL    string    `json:"serverURL"`
	CreatedAt    time.Time `json:"createdAt"`
}

type ClientManager 

type ClientManager struct {
	// contains filtered or unexported fields
}

ClientManager manages MCP clients for multiple users

func NewClientManager 

func NewClientManager(config Config, log pluginapi.LogService, pluginAPI *pluginapi.Client, oauthManager *OAuthManager) *ClientManager

NewClientManager creates a new MCP client manager

func (*ClientManager) Close 

func (m *ClientManager) Close()

Close closes the client manager and all managed clients The client manger should not be used after Close is called

func (*ClientManager) GetOAuthManager added in v1.4.0 

func (m *ClientManager) GetOAuthManager() *OAuthManager

GetOAuthManager returns the OAuth manager instance

func (*ClientManager) GetToolsForUser 

func (m *ClientManager) GetToolsForUser(userID string) ([]llm.Tool, *Errors)

GetToolsForUser returns the tools available for a specific user

func (*ClientManager) ProcessOAuthCallback added in v1.4.0 

func (m *ClientManager) ProcessOAuthCallback(ctx context.Context, userID, state, code string) (*OAuthSession, error)

ProcessOAuthCallback processes the OAuth callback for a user

func (*ClientManager) ReInit 

func (m *ClientManager) ReInit(config Config)

ReInit re-initializes the client manager with a new configuration

type Config 

type Config struct {
	Enabled            bool           `json:"enabled"`
	Servers            []ServerConfig `json:"servers"`
	IdleTimeoutMinutes int            `json:"idleTimeoutMinutes"`
}

Config contains the configuration for the MCP servers

type Errors added in v1.4.0 

type Errors struct {
	ToolAuthErrors []llm.ToolAuthError // Authentication errors users need to resolve
	Errors         []error             // Generic errors (connection, config, etc.)
}

Errors represents a collection of errors from MCP operations.

type OAuthManager added in v1.4.0 

type OAuthManager struct {
	// contains filtered or unexported fields
}

func NewOAuthManager added in v1.4.0 

func NewOAuthManager(pluginAPI mmapi.Client, callbackURL string) *OAuthManager

func (*OAuthManager) InitiateOAuthFlow added in v1.4.0 

func (m *OAuthManager) InitiateOAuthFlow(ctx context.Context, userID, serverID, serverURL, metadataURL string) (string, error)

func (*OAuthManager) ProcessCallback added in v1.4.0 

func (m *OAuthManager) ProcessCallback(ctx context.Context, loggedInUserID, state, code string) (*OAuthSession, error)

type OAuthNeededError added in v1.4.0 

type OAuthNeededError struct {
	// contains filtered or unexported fields
}

func (*OAuthNeededError) AuthURL added in v1.4.0 

func (e *OAuthNeededError) AuthURL() string

func (*OAuthNeededError) Error added in v1.4.0 

func (e *OAuthNeededError) Error() string

func (*OAuthNeededError) Unwrap added in v1.4.0 

func (e *OAuthNeededError) Unwrap() error

type OAuthSession added in v1.4.0 

type OAuthSession struct {
	UserID            string    `json:"userID"`
	ServerID          string    `json:"serverID"`
	ServerURL         string    `json:"serverURL"`
	ServerMetadataURL string    `json:"serverMetadataURL"`
	CodeVerifier      string    `json:"codeVerifier"`
	State             string    `json:"state"`
	CreatedAt         time.Time `json:"createdAt"`
}

type ProtectedResourceMetadata added in v1.4.0 

type ProtectedResourceMetadata struct {
	Resource             string   `json:"resource"`
	AuthorizationServers []string `json:"authorization_servers"`
}

ProtectedResourceMetadata represents the OAuth 2.0 Protected Resource Metadata (RFC 9728)

type RegistrationError added in v1.4.0 

type RegistrationError struct {
	ErrorCode        string         `json:"error"`
	ErrorDescription string         `json:"error_description,omitempty"`
	HTTPStatusCode   int            `json:"-"`
	HTTPResponse     *http.Response `json:"-"`
}

RegistrationError represents an error response per RFC 7591

func (*RegistrationError) Error added in v1.4.0 

func (e *RegistrationError) Error() string

type RegistrationRequest added in v1.4.0 

type RegistrationRequest struct {
	// Required fields
	RedirectURIs []string `json:"redirect_uris"`

	// Optional fields commonly used
	TokenEndpointAuthMethod string   `json:"token_endpoint_auth_method,omitempty"`
	GrantTypes              []string `json:"grant_types,omitempty"`
	ResponseTypes           []string `json:"response_types,omitempty"`
	ClientName              string   `json:"client_name,omitempty"`
	Scope                   string   `json:"scope,omitempty"`
	Contacts                []string `json:"contacts,omitempty"`

	// Additional optional fields can be added as needed
	ClientURI string `json:"client_uri,omitempty"`
	LogoURI   string `json:"logo_uri,omitempty"`
	ToSURI    string `json:"tos_uri,omitempty"`
	PolicyURI string `json:"policy_uri,omitempty"`
}

RegistrationRequest represents a client registration request per RFC 7591

func DefaultRegistrationRequest added in v1.4.0 

func DefaultRegistrationRequest(redirectURI, clientName string) *RegistrationRequest

DefaultRegistrationRequest creates a default registration request for MCP clients

type RegistrationResponse added in v1.4.0 

type RegistrationResponse struct {
	// Required fields
	ClientID string `json:"client_id"`

	// Optional fields
	ClientSecret          string `json:"client_secret,omitempty"`
	ClientIDIssuedAt      *int64 `json:"client_id_issued_at,omitempty"`
	ClientSecretExpiresAt *int64 `json:"client_secret_expires_at,omitempty"`

	// Echo back the registration metadata
	RedirectURIs            []string `json:"redirect_uris,omitempty"`
	TokenEndpointAuthMethod string   `json:"token_endpoint_auth_method,omitempty"`
	GrantTypes              []string `json:"grant_types,omitempty"`
	ResponseTypes           []string `json:"response_types,omitempty"`
	ClientName              string   `json:"client_name,omitempty"`
	Scope                   string   `json:"scope,omitempty"`
	Contacts                []string `json:"contacts,omitempty"`
	ClientURI               string   `json:"client_uri,omitempty"`
	LogoURI                 string   `json:"logo_uri,omitempty"`
	ToSURI                  string   `json:"tos_uri,omitempty"`
	PolicyURI               string   `json:"policy_uri,omitempty"`
}

RegistrationResponse represents the server's response per RFC 7591

func DiscoverAndRegisterClient added in v1.4.0 

func DiscoverAndRegisterClient(ctx context.Context, httpClient *http.Client, serverURL, callbackURL, clientID, initialAccessToken string) (*RegistrationResponse, error)

DiscoverAndRegisterClient performs the complete client registration flow: 1. Discovers the registration endpoint from server metadata 2. Creates a default registration request 3. Registers the client with the server

func RegisterClient added in v1.4.0 

func RegisterClient(ctx context.Context, httpClient *http.Client, registrationEndpoint string, request *RegistrationRequest, initialAccessToken string) (*RegistrationResponse, error)

RegisterClient performs dynamic client registration per RFC 7591

type ServerConfig 

type ServerConfig struct {
	Name    string            `json:"name"`
	Enabled bool              `json:"enabled"`
	BaseURL string            `json:"baseURL"`
	Headers map[string]string `json:"headers,omitempty"`
}

ServerConfig contains the configuration for a single MCP server

type ToolInfo added in v1.4.0 

type ToolInfo struct {
	Name        string                 `json:"name"`
	Description string                 `json:"description"`
	InputSchema map[string]interface{} `json:"inputSchema"`
}

ToolInfo represents a tool's metadata for discovery purposes

func DiscoverServerTools added in v1.4.0 

func DiscoverServerTools(
	ctx context.Context,
	userID string,
	serverConfig ServerConfig,
	log pluginapi.LogService,
	oauthManger *OAuthManager,
) ([]ToolInfo, error)

DiscoverServerTools creates a temporary connection to an MCP server and discovers its tools

type UserClients added in v1.4.0 

type UserClients struct {
	// contains filtered or unexported fields
}

UserClients represents a per-user MCP client with multiple server connections

func NewUserClients added in v1.4.0 

func NewUserClients(userID string, log pluginapi.LogService, oauthManager *OAuthManager) *UserClients

func (*UserClients) Close added in v1.4.0 

func (c *UserClients) Close()

Close closes all server connections for a user client

func (*UserClients) ConnectToAllServers added in v1.4.0 

func (c *UserClients) ConnectToAllServers(servers []ServerConfig) *Errors

ConnectToAllServers initializes connections to all provided servers

func (*UserClients) GetTools added in v1.4.0 

func (c *UserClients) GetTools() []llm.Tool

GetTools returns the tools available from the clients

Source Files

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