chore: release v4.5.0-rc.2 (#3702)

## Summary
3 improvements, 1 bug fix.

## Improvements
- The per-turn merge now overlays the wire copy's tool-part state
advancement onto the agent's existing chain — `state` + the matching
resolution field (`output` / `errorText` / `approval`) come from the
wire, everything else (text, reasoning, tool `input`, provider metadata)
stays whatever the snapshot or `hydrateMessages` returned. Previously a
full-message replace overwrote those fields with whatever the client
shipped, so a slimmed wire copy landed a tool call with no `arguments`
on the next LLM call. Covers `output-available` / `output-error` (HITL
`addToolOutput`) and `approval-responded` / `output-denied` (approval
flow).
- `TriggerChatTransport.sendMessages` and `AgentChat.sendRaw` now slim
assistant messages that carry advanced tool parts. The wire payload is
just `{ id, role, parts: [<state + resolution field>] }` for
`submit-message` continuations; everything else passes through.
Reasoning blobs and full tool inputs no longer ride the wire on every
`addToolOutput` / `addToolApproveResponse`, so continuation payloads
stay well under the `.in/append` cap on long agent loops.
- Add `TriggerClient` for running multiple SDK clients side-by-side,
each with its own auth, preview branch, and baseURL. Useful when a
single process needs to trigger tasks or read runs across multiple
projects, environments, or preview branches without mutating shared
global state.
([#3683](https://github.com/triggerdotdev/trigger.dev/pull/3683))

## Bug fixes
- Fix `chat.agent` HITL continuations on reasoning-heavy turns. Two
changes that work together:
([#3719](https://github.com/triggerdotdev/trigger.dev/pull/3719))

<details>
<summary>Raw changeset output</summary>

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`main` is currently in **pre mode** so this branch has prereleases
rather than normal releases. If you want to exit prereleases, run
`changeset pre exit` on `main`.

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# Releases
## @trigger.dev/build@4.5.0-rc.2

### Patch Changes

-   Updated dependencies:
    -   `@trigger.dev/core@4.5.0-rc.2`

## trigger.dev@4.5.0-rc.2

### Patch Changes

-   Updated dependencies:
    -   `@trigger.dev/build@4.5.0-rc.2`
    -   `@trigger.dev/core@4.5.0-rc.2`
    -   `@trigger.dev/schema-to-json@4.5.0-rc.2`

## @trigger.dev/plugins@4.5.0-rc.2

### Patch Changes

-   Updated dependencies:
    -   `@trigger.dev/core@4.5.0-rc.2`

## @trigger.dev/python@4.5.0-rc.2

### Patch Changes

-   Updated dependencies:
    -   `@trigger.dev/sdk@4.5.0-rc.2`
    -   `@trigger.dev/build@4.5.0-rc.2`
    -   `@trigger.dev/core@4.5.0-rc.2`

## @trigger.dev/react-hooks@4.5.0-rc.2

### Patch Changes

-   Updated dependencies:
    -   `@trigger.dev/core@4.5.0-rc.2`

## @trigger.dev/redis-worker@4.5.0-rc.2

### Patch Changes

-   Updated dependencies:
    -   `@trigger.dev/core@4.5.0-rc.2`

## @trigger.dev/rsc@4.5.0-rc.2

### Patch Changes

-   Updated dependencies:
    -   `@trigger.dev/core@4.5.0-rc.2`

## @trigger.dev/schema-to-json@4.5.0-rc.2

### Patch Changes

-   Updated dependencies:
    -   `@trigger.dev/core@4.5.0-rc.2`

## @trigger.dev/sdk@4.5.0-rc.2

### Patch Changes

- Fix `chat.agent` HITL continuations on reasoning-heavy turns. Two
changes that work together:
([#3719](https://github.com/triggerdotdev/trigger.dev/pull/3719))

- The per-turn merge now overlays the wire copy's tool-part state
advancement onto the agent's existing chain — `state` + the matching
resolution field (`output` / `errorText` / `approval`) come from the
wire, everything else (text, reasoning, tool `input`, provider metadata)
stays whatever the snapshot or `hydrateMessages` returned. Previously a
full-message replace overwrote those fields with whatever the client
shipped, so a slimmed wire copy landed a tool call with no `arguments`
on the next LLM call. Covers `output-available` / `output-error` (HITL
`addToolOutput`) and `approval-responded` / `output-denied` (approval
flow).
- `TriggerChatTransport.sendMessages` and `AgentChat.sendRaw` now slim
assistant messages that carry advanced tool parts. The wire payload is
just `{ id, role, parts: [<state + resolution field>] }` for
`submit-message` continuations; everything else passes through.
Reasoning blobs and full tool inputs no longer ride the wire on every
`addToolOutput` / `addToolApproveResponse`, so continuation payloads
stay well under the `.in/append` cap on long agent loops.

Note: `onValidateMessages` receives the slim wire on HITL turns. If you
call `validateUIMessages` from `ai` against the full `messages` array it
will reject the slim assistant; filter to user messages (or skip on HITL
turns) — see the updated docstring on `onValidateMessages` for the
recommended pattern.

For `hydrateMessages` hooks that persist the chain, this release also
adds a small helper to the `@trigger.dev/sdk/ai` surface:

    ```ts
    import { chat, upsertIncomingMessage } from "@trigger.dev/sdk/ai";

    chat.agent({
hydrateMessages: async ({ chatId, trigger, incomingMessages }) => {
const record = await db.chat.findUnique({ where: { id: chatId } });
        const stored = record?.messages ?? [];
if (upsertIncomingMessage(stored, { trigger, incomingMessages })) {
await db.chat.update({ where: { id: chatId }, data: { messages: stored }
});
        }
        return stored;
      },
    });
    ```

It pushes fresh user messages by id, no-ops on HITL continuations (the
incoming shares an id with the existing assistant — the runtime overlays
the new tool-state advance), and skips on non-`submit-message` triggers.
Returns `true` if it mutated `stored` so the caller knows whether to
persist.

Net effect: `chat.addToolOutput(...)` /
`chat.addToolApproveResponse(...)` on multi-step reasoning agents
(OpenAI Responses with `store: false`, Anthropic extended thinking,
etc.) no longer blows the cap and no longer corrupts the LLM input.

- Add `TriggerClient` for running multiple SDK clients side-by-side,
each with its own auth, preview branch, and baseURL. Useful when a
single process needs to trigger tasks or read runs across multiple
projects, environments, or preview branches without mutating shared
global state.
([#3683](https://github.com/triggerdotdev/trigger.dev/pull/3683))

    ```ts
    import { TriggerClient } from "@trigger.dev/sdk";

const prod = new TriggerClient({ accessToken:
process.env.TRIGGER_PROD_KEY });
    const preview = new TriggerClient({
      accessToken: process.env.TRIGGER_PREVIEW_KEY,
      previewBranch: "signup-flow",
    });

    await prod.tasks.trigger("send-email", payload);
    await preview.runs.list({ status: ["COMPLETED"] });
    ```

-   Updated dependencies:
    -   `@trigger.dev/core@4.5.0-rc.2`

## @trigger.dev/core@4.5.0-rc.2

</details>

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

packages/python/CHANGELOG.md

@@ -1,5 +1,14 @@
 # @trigger.dev/python
 
+## 4.5.0-rc.2
+
+### Patch Changes
+
+- Updated dependencies:
+  - `@trigger.dev/sdk@4.5.0-rc.2`
+  - `@trigger.dev/build@4.5.0-rc.2`
+  - `@trigger.dev/core@4.5.0-rc.2`
+
 ## 4.5.0-rc.1
 
 ### Patch Changes

packages/python/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@trigger.dev/python",
-  "version": "4.5.0-rc.1",
+  "version": "4.5.0-rc.2",
   "description": "Python runtime and build extension for Trigger.dev",
   "license": "MIT",
   "publishConfig": {
@@ -45,7 +45,7 @@
     "check-exports": "attw --pack ."
   },
   "dependencies": {
-    "@trigger.dev/core": "workspace:4.5.0-rc.1",
+    "@trigger.dev/core": "workspace:4.5.0-rc.2",
     "tinyexec": "^0.3.2"
   },
   "devDependencies": {
@@ -56,12 +56,12 @@
     "tsx": "4.17.0",
     "esbuild": "^0.23.0",
     "@arethetypeswrong/cli": "^0.15.4",
-    "@trigger.dev/build": "workspace:4.5.0-rc.1",
-    "@trigger.dev/sdk": "workspace:4.5.0-rc.1"
+    "@trigger.dev/build": "workspace:4.5.0-rc.2",
+    "@trigger.dev/sdk": "workspace:4.5.0-rc.2"
   },
   "peerDependencies": {
-    "@trigger.dev/sdk": "workspace:^4.5.0-rc.1",
-    "@trigger.dev/build": "workspace:^4.5.0-rc.1"
+    "@trigger.dev/sdk": "workspace:^4.5.0-rc.2",
+    "@trigger.dev/build": "workspace:^4.5.0-rc.2"
   },
   "engines": {
     "node": ">=18.20.0"