Package io.meeds.mcp.server.service

Class McpToolApprovalService

java.lang.Object

io.meeds.mcp.server.service.McpToolApprovalService

@Component
public class McpToolApprovalService
extends Object

Asks the user to approve a tool call on a card in their chat, and waits for the answer. The answer travels over CometD as answer:<id>:<true|false> or, for "Always allow", answer:<id>:always:<AGENT|TOOL>:<days>:<CONSTRAINED|ANY>. Only the client subscribed as the requesting user may answer, the first answer wins, and an "Always allow" answer creates its standing approval once, from the pending call the server recorded.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
class	McpToolApprovalService.WebSocketServerListener	Reads card answers published by the chat on COMETD_CHANNEL.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	COMETD_CHANNEL

Constructor Summary

Constructors

Constructor	Description
McpToolApprovalService()

Method Summary

Modifier and Type	Method	Description
void	init()	Listens to answers on the CometD channel and starts the periodic timeout check of pending cards.
void	receiveAnswer(String id, String wsClientId, boolean approved)	Records a plain approve or deny answer.
void	receiveAnswer(String id, String wsClientId, boolean approved, boolean always, McpToolGrantChoice choice)	Records an answer to a pending card.
boolean	requestApproval(String id, String conversationId, String toolName, String toolInput, String username)	Asks the user to approve a call on a card without "Always allow", and waits for the answer.
boolean	requestApproval(String id, String conversationId, String toolName, String toolInput, String username, McpToolGrantRequest grantRequest, boolean grantable, McpToolGrantConstraint offeredConstraint)	Asks the user to approve a call on a card, offering "Always allow" when the call is grantable, and waits for the answer.
void	shutdown()	Stops the periodic timeout check.
void	traceToolExecution(UserToolExecution toolExecution)	Publishes one step of a tool call to the user's chat and to the platform listeners (ai-agent-tool-execution).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

COMETD_CHANNEL

public static final String COMETD_CHANNEL

See Also:

• Constant Field Values

Constructor Details

McpToolApprovalService

public McpToolApprovalService()

Method Details

init

@PostConstruct
public void init()

Listens to answers on the CometD channel and starts the periodic timeout check of pending cards.

shutdown

@PreDestroy
public void shutdown()

Stops the periodic timeout check.

requestApproval

public boolean requestApproval(String id,
 String conversationId,
 String toolName,
 String toolInput,
 String username)

Asks the user to approve a call on a card without "Always allow", and waits for the answer.

Parameters:

id - the call identifier

conversationId - the chat conversation showing the card

toolName - the tool name shown on the card

toolInput - the call input shown on the card

username - the user asked

Returns:

true when the user approved

requestApproval

public boolean requestApproval(String id,
 String conversationId,
 String toolName,
 String toolInput,
 String username,
 McpToolGrantRequest grantRequest,
 boolean grantable,
 McpToolGrantConstraint offeredConstraint)

Asks the user to approve a call on a card, offering "Always allow" when the call is grantable, and waits for the answer.

Parameters:

id - the call identifier

conversationId - the chat conversation showing the card

toolName - the tool name shown on the card

toolInput - the call input shown on the card

username - the user asked

grantRequest - the call as the server resolved it, the only source of a grant created from this card

grantable - whether the card may offer "Always allow"

offeredConstraint - the argument limit the card may offer, or null

Returns:

true when the user approved, once or always

receiveAnswer

public void receiveAnswer(String id,
 String wsClientId,
 boolean approved)
                   throws IllegalAccessException

Records a plain approve or deny answer.

Parameters:

id - the call identifier

wsClientId - the CometD client that sent the answer

approved - the answer

Throws:

IllegalAccessException - when the client isn't subscribed as the requesting user

receiveAnswer

public void receiveAnswer(String id,
 String wsClientId,
 boolean approved,
 boolean always,
 McpToolGrantChoice choice)
                   throws IllegalAccessException

Records an answer to a pending card. Only the client subscribed as the requesting user may answer, and only the first answer counts: the card resends its answer every half second until it is confirmed, so a later copy changes nothing and never creates a second grant. An "Always allow" answer approves the call and, when the card was grantable and the choice valid, creates the standing approval from the pending call; otherwise it approves the call once, creates nothing, and is logged. The grant is created outside the card's lock: its store may be slow, and the lock is the one the timeout checker takes to wake every pending card.

Parameters:

id - the call identifier

wsClientId - the CometD client that sent the answer

approved - whether the call is approved

always - whether the answer is "Always allow"

choice - the checked "Always allow" choice, null when invalid

Throws:

IllegalAccessException - when the client isn't subscribed as the requesting user

traceToolExecution

public void traceToolExecution(UserToolExecution toolExecution)

Publishes one step of a tool call to the user's chat and to the platform listeners (ai-agent-tool-execution). A call run under a standing approval carries the grant id and its owner type.

Parameters:

toolExecution - the step to publish