utils/messages/message_utils library

Classes

AssistantMessage

Assistant message.

AttachmentMessage

Attachment message.

ContentBlock

A content block within a message.

ImageBlock

Image content block.

Message

Base message type.

MessageLookups

Pre-computed lookups for O(1) access to message relationships.

NormalizedMessage

A normalized message with exactly one content block.

ProgressMessage

Progress message for tool execution.

SystemMessage

System message.

TextBlock

Text content block.

ToolResultBlock

Tool result content block.

ToolUseBlock

Tool use content block.

Usage

Usage statistics for an API response.

UserMessage

User message.

Enums

HookEvent

Hook event types.

MessageOrigin

Origin of a message.

MessageType

Message types in the conversation.

PermissionMode

Permission mode for message context.

SystemMessageLevel

System message severity level.

SystemMessageSubtype

System message subtypes.

Constants

cancelMessage → const String

denialWorkaroundGuidance → const String

interruptMessage → const String

interruptMessageForToolUse → const String

noContentMessage → const String

noResponseRequested → const String

planRejectionPrefix → const String

rejectMessage → const String

rejectMessageWithReasonPrefix → const String

subagentRejectMessage → const String

subagentRejectMessageWithReasonPrefix → const String

syntheticModel → const String

syntheticToolResultPlaceholder → const String

Properties

syntheticMessages → Set<String>

final

Functions

autoRejectMessage(String toolName) → String

Build an auto-reject message for a denied tool.

buildClassifierUnavailableMessage(String toolName, String classifierModel) → String

Build a message for when the classifier is temporarily unavailable.

buildMessageLookups(List<Message> normalizedMessages, List<Message> messages) → MessageLookups

Build pre-computed lookups for O(1) access to message relationships.

buildYoloRejectionMessage(String reason) → String

Build a rejection message for auto mode classifier denials.

createAssistantAPIErrorMessage({required String content, Map<String, dynamic>? apiError, Map<String, dynamic>? error, String? errorDetails}) → AssistantMessage

Create an assistant API error message.

createAssistantMessage({required dynamic content, Usage? usage, bool? isVirtual}) → AssistantMessage

Create an assistant message.

createProgressMessage({required String toolUseID, required String parentToolUseID, required Map<String, dynamic> data}) → ProgressMessage

Create a progress message.

createToolResultStopMessage(String toolUseID) → ToolResultBlock

Create a tool result stop message.

createUserInterruptionMessage({bool toolUse = false}) → UserMessage

Create a user interruption message.

createUserMessage({required dynamic content, bool? isMeta, bool? isVisibleInTranscriptOnly, bool? isVirtual, bool? isCompactSummary, dynamic toolUseResult, Map<String, dynamic>? mcpMeta, String? uuid, String? timestamp, List<int>? imagePasteIds, String? sourceToolAssistantUUID, PermissionMode? permissionMode, MessageOrigin? origin, Map<String, dynamic>? summarizeMetadata}) → UserMessage

Create a user message with the given content.

deriveShortMessageId(String uuid) → String

Derive a short stable message ID (6-char base36) from a UUID.

deriveUUID(String parentUUID, int index) → String

Deterministic UUID derivation from parent UUID + index.

dontAskRejectMessage(String toolName) → String

Build a don't-ask reject message for a denied tool.

extractTag(String html, String tagName) → String?

Extract content from an XML-like tag in a string.

extractTextContent(Message message) → String

Extract text content from a message.

getLastAssistantMessage(List<Message> messages) → AssistantMessage?

Get the last assistant message from a list.

getProgressMessagesFromLookup(Message message, MessageLookups lookups) → List<ProgressMessage>

Get progress messages from lookup.

getSiblingToolUseIDsFromLookup(Message message, MessageLookups lookups) → Set<String>

Get sibling tool use IDs from lookup.

getToolResultIDs(List<Message> messages) → Map<String, bool>

Get tool result IDs from normalized messages.

getToolUseID(Message message) → String?

Get the tool use ID from a normalized message.

getToolUseIDs(List<Message> messages) → Set<String>

Get all tool use IDs from a list of messages.

getUserMessageText(Message message) → String

Get user message text content.

hasToolCallsInLastAssistantTurn(List<Message> messages) → bool

Check if the last assistant turn has tool calls.

hasUnresolvedHooksFromLookup(String toolUseID, HookEvent hookEvent, MessageLookups lookups) → bool

Check for unresolved hooks using pre-computed lookup.

isClassifierDenial(String content) → bool

Check if a tool result is a classifier denial.

isNotEmptyMessage(Message message) → bool

Check if a message is not empty.

isSyntheticMessage(Message message) → bool

Check if a message is synthetic (interrupt, cancel, reject, etc.).

isThinkingMessage(Message message) → bool

Check if a message is a thinking message (extended thinking).

isToolUseRequestMessage(Message message) → bool

Check if a message is a tool use request.

isToolUseResultMessage(Message message) → bool

Check if a message is a tool use result.

mergeAssistantMessages(AssistantMessage a, AssistantMessage b) → AssistantMessage

Merge two assistant messages.

mergeUserMessages(UserMessage a, UserMessage b) → UserMessage

Merge two user messages.

mergeUserMessagesAndToolResults(UserMessage a, UserMessage b) → UserMessage

Merge two user messages including tool results.

prepareUserContent({required String inputString, required List<ContentBlock> precedingInputBlocks}) → dynamic

Prepare user content with preceding input blocks.

withMemoryCorrectionHint(String message, {bool autoMemoryEnabled = false}) → String

Append a memory correction hint when auto-memory is enabled.

wrapInSystemReminder(String text) → String

Wrap text in system-reminder XML tags.