[isekovanic]

Ticket: https://linear.app/stream/issue/RN-485

Stacked on #3921.

🎯 Goal

Show an agent reply's steps: its rounds of reasoning, its tool calls, and the questions a tool asks before it runs. The views are ported from React's AI components (#3376). Effects follow the native SDKs instead.

🛠 Implementation details

Views (all props-only, none of them reads <Channel>)

• AIReasoning shows a header that counts up while the agent thinks ("Thinking... 7s") and then reads "Thought for 12s" with the step's summary.
  • The panel opens while the agent thinks and follows the reasoning as it streams in, then folds once the step is done. Tapping the header opens or folds it.
  • The first step takes over the turn's thinking clock, so the time carries on from AIThinking.
• AIThinking is the same header for a turn that hasn't shown any reasoning yet.
• AIToolCall shows the call's title, a detail line, a status icon and its duration. The detail line covers waiting for approval, a sign-in or the device, and declined, didn't complete or cancelled.
• AIToolApproval and AIToolApprovalCard ask the person a tool's question, such as "Share your location?", with the agent's reason and Allow / Don't Allow.
  • The question is only asked of the targeted user on the targeted install.
  • The buttons wait while the answer is sent, and a failed send lets the person answer again.
• AIMessageParts / AIMessagePart render a reply's steps in order, with a neutral line for a kind this version can't show.
• AIToolApproverProvider / useAIToolApprover say who answers the questions on this device.

Shared bits

• In-progress states use our NativeShimmerView through a small internal Shimmer, which AITypingIndicatorView now uses too. Running calls use the platform ActivityIndicator. This matches Swift and Android, not React's CSS.
• Durations come out as "0.4s" and "1m 5s" on both platforms. Hermes on iOS ignores narrow units in Intl, so we fall back the same way React does.
• There's a new, optional messageParts section in the AI theme.
• New strings are added to all 13 locales. The thinking header reuses the existing Thinking... key. The ar and he translations are new and could use a native speaker's look.

ExpoChatGPTSample

• A reply renders its steps above its text.
• Live reasoning comes from calypso's LiveReasoning, fed by message.updated, and "thinking" comes from the session's state.
• Approvals go through session.decide.
• The drawer lists the router's sessions.
• The steps take the row's full width. The stand-in MessageList sizes bubbles to their content, and AIConversation replaces it later anyway.

🎨 UI Changes

Reasoning steps (folded, open, streaming), tool calls (running, waiting, done, failed, declined) and the approval card.

🧪 Testing

• Unit tests are ported from React's AIMessagePartViews suite, plus duration formatting, including the iOS fallback.
• On an Android emulator against a local Vision-Agents router:
  • thinking, the reasoning steps folding and opening, and a web search with its spinner, check and duration;
  • the approval card: Share runs the call, Not now declines it, and no answer shows the call as failed after the router's 30s;
  • reasoning streaming into an open panel. Our router's models send their thinking in one piece, so this was driven with router-shaped events.
• On the iOS simulator: a reply with a web search step and its duration.
• To get an approval at all, the sample needs a phone-side tool, and the question has to carry the install id (/respond with client_id). calypso 0.2.3's responses.create doesn't send one. Both come with the client tool runner later in this stack.
• Not tested: RTL and screen readers, on either platform.
• yarn lint, yarn typecheck, yarn build and yarn test:unit pass.

☑️ Checklist

• I have signed the Stream CLA (required)
• PR targets the develop branch (stacked on feat(ai-components): AI translations via the chat SDK, AI sample on the agents router #3921)
• Documentation is updated
• New code is tested in main example apps, including all possible scenarios
  • SampleApp iOS and Android
  • Expo iOS and Android

[Stream-SDK-Bot]

SDK Size

title	develop	branch	diff	status
js_bundle_size	2037 KB	2038 KB	+213 B	🟢
ai_components_size	163 KB	196 KB	+34134 B	🔴