[Agent Builder] Rename send message references to streaming context (#268876)

Author: chrisbmar

x-pack/platform/plugins/shared/agent_builder/CONTRIBUTOR_GUIDE.md

@@ -1322,31 +1322,40 @@ The full implementation is ~130 lines and serves as the reference for new types.
 
 ## Streams lifecycle (frontend)
 
-The chat streaming layer lives in `public/application/context/send_message/`. This section
-documents how mutations, lifted state, and the React Query cache fit together. Read this
-before touching any of:
-`send_message_context.tsx`, `use_send_message.ts`, `use_send_message_mutation.ts`,
-`use_resume_round_mutation.ts`, `use_subscribe_to_chat_events.ts`,
+The chat streaming layer lives across two folders:
+
+- `public/application/context/streaming/` — the lifted provider, its context hook, the
+  send/regenerate and resume mutation hooks, the chat-events subscriber, and shared types.
+- `public/application/hooks/` — the per-conversation convenience hook
+  (`use_conversation_stream.ts`) and the "any stream active?" derived hook
+  (`use_is_any_conversation_streaming.ts`). They live here because they compose
+  `useConversation` (a sibling in `hooks/`) with the streaming context.
+
+This section documents how mutations, lifted state, and the React Query cache fit
+together. Read this before touching any of: `streaming_context.tsx`,
+`use_send_message_mutation.ts`, `use_resume_round_mutation.ts`,
+`use_subscribe_to_chat_events.ts`, `use_conversation_stream.ts`,
 `use_is_any_conversation_streaming.ts`.
 
 ### The lift
 
-`<SendMessageProvider>` is mounted **once** above the routes/sidebar:
+`<StreamingProvider>` is mounted **once** above the routes/sidebar:
 
 - Routed app: in `mount.tsx`, above `<AgentBuilderRoutes>`. The sidebar is part of the
   routes, so it can read streaming state directly.
 - Embeddable: in `embeddable_conversations_provider.tsx`, one provider per embeddable
   instance because each instance has its own `QueryClient`.
 
-The sidebar uses `useSendMessageContext()` directly. `useIsAnyConversationStreaming()`
+The sidebar uses `useStreamingContext()` directly. `useIsAnyConversationStreaming()`
 is derived from the same context and is used by the page-leave guard and the
 embeddable welcome-message dismiss — both genuinely care about "is anything in
 flight, anywhere?". Anything inside the conversation tree should use the per-conversation
-scoped hook, `useSendMessage()` (in `use_send_message.ts`).
+scoped hook, `useConversationStream()` (in `hooks/use_conversation_stream.ts`).
+
 
 ### Lifted state
 
-`SendMessageProvider` owns two slices with split lifecycles:
+`StreamingProvider` owns two slices with split lifecycles:
 
 - `activeStreams: Map<conversationId, { type, agentReasoning }>` — one entry per
   in-flight stream. Set synchronously when each mutation kicks off; deleted in the
@@ -1426,7 +1435,7 @@ cache, B writes to its own. Cancelling one doesn't affect the other.
 What this means in practice:
 
 - **Submit gate** (`conversation_input.tsx`) is per-conversation: `isResponseLoading`
-  from `useSendMessage()`. The new-conversation route (`/conversations/new`) has
+  from `useConversationStream()`. The new-conversation route (`/conversations/new`) has
   no `conversationId`, so `isResponseLoading` is `false` and submit is always
   allowed there even while other conversations stream.
 - **HITL Approve / Cancel gate** (`round_layout.tsx`) is per-conversation:

x-pack/platform/plugins/shared/agent_builder/public/application/components/conversations/actions/start_new_conversation_button.tsx

@@ -9,7 +9,7 @@ import React, { useCallback } from 'react';
 import { EuiButton } from '@elastic/eui';
 import { i18n } from '@kbn/i18n';
 import { useConversationContext } from '../../../context/conversation/conversation_context';
-import { useSendMessage } from '../../../context/send_message/send_message_context';
+import { useConversationStream } from '../../../hooks/use_conversation_stream';
 import { useNavigation } from '../../../hooks/use_navigation';
 import { useLastAgentId } from '../../../hooks/use_last_agent_id';
 import { appPaths } from '../../../utils/app_paths';
@@ -24,7 +24,7 @@ const NEW_CONVERSATION_BUTTON_LABEL = i18n.translate(
 export const StartNewConversationButton: React.FC = () => {
   const { navigateToAgentBuilderUrl } = useNavigation();
   const { isEmbeddedContext, setConversationId } = useConversationContext();
-  const { removeError } = useSendMessage();
+  const { removeError } = useConversationStream();
   const lastAgentId = useLastAgentId();
 
   const handleClick = useCallback(() => {

x-pack/platform/plugins/shared/agent_builder/public/application/components/conversations/conversation.tsx

@@ -25,10 +25,8 @@ import { ConversationRounds } from './conversation_rounds/conversation_rounds';
 import { NewConversationPrompt } from './new_conversation_prompt';
 import { useConversationId } from '../../context/conversation/use_conversation_id';
 import { useShouldStickToBottom } from '../../context/conversation/use_should_stick_to_bottom';
-import {
-  useSendMessage,
-  useSendMessageContext,
-} from '../../context/send_message/send_message_context';
+import { useConversationStream } from '../../hooks/use_conversation_stream';
+import { useStreamingContext } from '../../context/streaming/streaming_context';
 import { useIsAnyConversationStreaming } from '../../hooks/use_is_any_conversation_streaming';
 import { useConversationScrollActions } from '../../hooks/use_conversation_scroll_actions';
 import { useConversationStatus } from '../../hooks/use_conversation';
@@ -56,9 +54,9 @@ export const Conversation: React.FC<{}> = () => {
   const { euiTheme } = useEuiTheme();
   const conversationId = useConversationId();
   const hasActiveConversation = useHasActiveConversation();
-  const { isResponseLoading } = useSendMessage();
+  const { isResponseLoading } = useConversationStream();
   const isAnyStreaming = useIsAnyConversationStreaming();
-  const { cancelAllStreams } = useSendMessageContext();
+  const { cancelAllStreams } = useStreamingContext();
   const conversationRounds = useConversationRounds();
   const lastRound = conversationRounds.at(-1);
   const { isFetched } = useConversationStatus();

x-pack/platform/plugins/shared/agent_builder/public/application/components/conversations/conversation_input/conversation_input.tsx

@@ -17,7 +17,7 @@ import { i18n } from '@kbn/i18n';
 import type { PropsWithChildren } from 'react';
 import React, { useEffect, useMemo } from 'react';
 import { useConversationId } from '../../../context/conversation/use_conversation_id';
-import { useSendMessage } from '../../../context/send_message/send_message_context';
+import { useConversationStream } from '../../../hooks/use_conversation_stream';
 import { useSubmitMessage } from '../../../hooks/use_submit_message';
 import { useAgentBuilderAgents } from '../../../hooks/agents/use_agents';
 import { useValidateAgentId } from '../../../hooks/agents/use_validate_agent_id';
@@ -144,7 +144,7 @@ export const ConversationInput: React.FC<ConversationInputProps> = ({
   onSubmit,
   onEditorFocus,
 }) => {
-  const { pendingMessage, error, isResuming, isResponseLoading } = useSendMessage();
+  const { pendingMessage, error, isResuming, isResponseLoading } = useConversationStream();
   const { isFetched } = useAgentBuilderAgents();
   const agentId = useAgentId();
   const conversationId = useConversationId();

x-pack/platform/plugins/shared/agent_builder/public/application/components/conversations/conversation_input/input_actions/conversation_action_button.tsx

@@ -9,7 +9,7 @@ import React from 'react';
 import { EuiButtonIcon, useEuiTheme } from '@elastic/eui';
 import { css } from '@emotion/react';
 import { i18n } from '@kbn/i18n';
-import { useSendMessage } from '../../../../context/send_message/send_message_context';
+import { useConversationStream } from '../../../../hooks/use_conversation_stream';
 
 interface ConversationActionButtonProps {
   onSubmit: () => void;
@@ -31,7 +31,7 @@ export const ConversationActionButton: React.FC<ConversationActionButtonProps> =
   isSubmitDisabled,
   resetToPendingMessage,
 }) => {
-  const { canCancel, cancel } = useSendMessage();
+  const { canCancel, cancel } = useConversationStream();
   const { euiTheme } = useEuiTheme();
 
   const cancelButtonStyles = css`

x-pack/platform/plugins/shared/agent_builder/public/application/components/conversations/conversation_rounds/round_layout.tsx

@@ -21,7 +21,7 @@ import { isConfirmationPrompt } from '@kbn/agent-builder-common/agents';
 import { RoundInput } from './round_input';
 import { RoundThinking } from './round_thinking/round_thinking';
 import { RoundResponse } from './round_response/round_response';
-import { useSendMessage } from '../../../context/send_message/send_message_context';
+import { useConversationStream } from '../../../hooks/use_conversation_stream';
 import { RoundError } from './round_error/round_error';
 import { ConfirmationPrompt } from './round_prompt';
 import { RoundAttachmentReferences } from './round_attachment_references';
@@ -91,7 +91,7 @@ export const RoundLayout: React.FC<RoundLayoutProps> = ({
     retry: retrySendMessage,
     resumeRound,
     isResuming,
-  } = useSendMessage();
+  } = useConversationStream();
   // HITL Approve / Cancel is per-conversation: streamActions are closure-bound to
   // vars.conversationId, so other in-flight conversations cannot corrupt this cache.
   // Use `isStreaming` (not `isResponseLoading`) so the buttons stay disabled during the

x-pack/platform/plugins/shared/agent_builder/public/application/components/conversations/conversation_rounds/round_response/round_response_actions.tsx

@@ -11,7 +11,7 @@ import copy from 'copy-to-clipboard';
 import React, { useCallback } from 'react';
 import { i18n } from '@kbn/i18n';
 import { useToasts } from '../../../../hooks/use_toasts';
-import { useSendMessage } from '../../../../context/send_message/send_message_context';
+import { useConversationStream } from '../../../../hooks/use_conversation_stream';
 
 const labels = {
   copy: i18n.translate('xpack.agentBuilder.roundResponseActions.copy', {
@@ -37,7 +37,7 @@ export const RoundResponseActions: React.FC<RoundResponseActionsProps> = ({
   isLastRound,
 }) => {
   const { addSuccessToast } = useToasts();
-  const { regenerate, isRegenerating, isResponseLoading } = useSendMessage();
+  const { regenerate, isRegenerating, isResponseLoading } = useConversationStream();
 
   const handleCopy = useCallback(() => {
     const isSuccess = copy(content);

x-pack/platform/plugins/shared/agent_builder/public/application/components/conversations/conversation_rounds/round_thinking/round_thinking_title.tsx

@@ -9,7 +9,7 @@ import { EuiFlexGroup, EuiFlexItem, EuiIcon, EuiText } from '@elastic/eui';
 import React from 'react';
 import { i18n } from '@kbn/i18n';
 import { css } from '@emotion/react';
-import { useSendMessage } from '../../../../context/send_message/send_message_context';
+import { useConversationStream } from '../../../../hooks/use_conversation_stream';
 import { RoundIcon } from './round_icon';
 import { lineClampStyles } from '../../../../../common.styles';
 
@@ -38,7 +38,7 @@ interface RoundThinkingTitleProps {
 const MIN_HEIGHT = '40px';
 
 export const RoundThinkingTitle = ({ isLoading, hasSteps, onShow }: RoundThinkingTitleProps) => {
-  const { agentReasoning } = useSendMessage();
+  const { agentReasoning } = useConversationStream();
 
   let thinkingButtonLabel = thinkingCompletedLabel;
   if (isLoading) {

x-pack/platform/plugins/shared/agent_builder/public/application/components/conversations/conversation_rounds/rounds_screen_reader_status.tsx

@@ -10,7 +10,7 @@ import React, { useEffect, useRef, useState } from 'react';
 import type { ConversationRound } from '@kbn/agent-builder-common';
 import { css } from '@emotion/react';
 import { euiScreenReaderOnly } from '@elastic/eui';
-import { useSendMessage } from '../../../context/send_message/send_message_context';
+import { useConversationStream } from '../../../hooks/use_conversation_stream';
 
 // Intervals grow by 5s each announcement, capped at 30s.
 // e.g. announcements fire at: 0s, 5s, 15s, 30s, 50s, 75s, 105s, 135s, ...
@@ -66,7 +66,7 @@ const useGeneratingAnnouncements = (isActive: boolean) => {
 export const RoundsScreenReaderStatus: React.FC<{ lastRound?: ConversationRound }> = ({
   lastRound,
 }) => {
-  const { isResponseLoading } = useSendMessage();
+  const { isResponseLoading } = useConversationStream();
   const announcement = useGeneratingAnnouncements(isResponseLoading);
 
   const responseWasLoading = useRef(false);

x-pack/platform/plugins/shared/agent_builder/public/application/components/conversations/embeddable_conversation_header/agents_popover_view.tsx

@@ -20,7 +20,7 @@ import { css } from '@emotion/react';
 import { i18n } from '@kbn/i18n';
 import type { AgentDefinition } from '@kbn/agent-builder-common';
 import { useConversationContext } from '../../../context/conversation/conversation_context';
-import { useSendMessageContext } from '../../../context/send_message/send_message_context';
+import { useStreamingContext } from '../../../context/streaming/streaming_context';
 import { useAgentBuilderAgents } from '../../../hooks/agents/use_agents';
 import { useNavigation } from '../../../hooks/use_navigation';
 import { appPaths } from '../../../utils/app_paths';
@@ -56,7 +56,7 @@ export const AgentsPopoverView: React.FC<AgentsPopoverViewProps> = ({
 }) => {
   const { euiTheme } = useEuiTheme();
   const { agentId, setAgentId } = useConversationContext();
-  const { removeAllErrors } = useSendMessageContext();
+  const { removeAllErrors } = useStreamingContext();
   const { agents } = useAgentBuilderAgents();
   const { agentOptions, renderAgentOption } = useAgentOptions({ agents, selectedAgentId: agentId });