TanStack · github-actions · May 6, 2026
diff --git a/.changeset/thinking-blocks-per-step.md b/.changeset/thinking-blocks-per-step.md
diff --git a/examples/ts-svelte-chat/CHANGELOG.md b/examples/ts-svelte-chat/CHANGELOG.md
@@ -1,5 +1,18 @@
 # ts-svelte-chat
 
+## 0.1.39
+
+### Patch Changes
+
+- Updated dependencies [[`b2d3cc1`](https://github.com/TanStack/ai/commit/b2d3cc131a31c54bd1e5841f958fbe333514e508)]:
+  - @tanstack/ai@0.15.0
+  - @tanstack/ai-anthropic@0.8.4
+  - @tanstack/ai-client@0.9.0
+  - @tanstack/ai-gemini@0.10.1
+  - @tanstack/ai-ollama@0.6.11
+  - @tanstack/ai-openai@0.8.3
+  - @tanstack/ai-svelte@0.7.1
+
 ## 0.1.38
 
 ### Patch Changes

diff --git a/examples/ts-svelte-chat/package.json b/examples/ts-svelte-chat/package.json
@@ -1,7 +1,7 @@
 {
   "name": "ts-svelte-chat",
   "private": true,
-  "version": "0.1.38",
+  "version": "0.1.39",
   "type": "module",
   "scripts": {
     "dev": "vite dev --port 3000",

diff --git a/examples/ts-vue-chat/CHANGELOG.md b/examples/ts-vue-chat/CHANGELOG.md
@@ -1,5 +1,19 @@
 # ts-vue-chat
 
+## 0.1.39
+
+### Patch Changes
+
+- Updated dependencies [[`b2d3cc1`](https://github.com/TanStack/ai/commit/b2d3cc131a31c54bd1e5841f958fbe333514e508)]:
+  - @tanstack/ai@0.15.0
+  - @tanstack/ai-anthropic@0.8.4
+  - @tanstack/ai-client@0.9.0
+  - @tanstack/ai-gemini@0.10.1
+  - @tanstack/ai-ollama@0.6.11
+  - @tanstack/ai-openai@0.8.3
+  - @tanstack/ai-vue@0.7.1
+  - @tanstack/ai-vue-ui@0.1.32
+
 ## 0.1.38
 
 ### Patch Changes

diff --git a/examples/ts-vue-chat/package.json b/examples/ts-vue-chat/package.json
@@ -1,6 +1,6 @@
 {
   "name": "ts-vue-chat",
-  "version": "0.1.38",
+  "version": "0.1.39",
   "private": true,
   "type": "module",
   "scripts": {

diff --git a/examples/vanilla-chat/CHANGELOG.md b/examples/vanilla-chat/CHANGELOG.md
@@ -1,5 +1,12 @@
 # vanilla-chat
 
+## 0.0.36
+
+### Patch Changes
+
+- Updated dependencies [[`b2d3cc1`](https://github.com/TanStack/ai/commit/b2d3cc131a31c54bd1e5841f958fbe333514e508)]:
+  - @tanstack/ai-client@0.9.0
+
 ## 0.0.35
 
 ### Patch Changes

diff --git a/examples/vanilla-chat/package.json b/examples/vanilla-chat/package.json
@@ -2,7 +2,7 @@
   "name": "vanilla-chat",
   "private": true,
   "type": "module",
-  "version": "0.0.35",
+  "version": "0.0.36",
   "scripts": {
     "start": "vite --port 3001",
     "dev": "vite --port 3001",

diff --git a/packages/typescript/ai-anthropic/CHANGELOG.md b/packages/typescript/ai-anthropic/CHANGELOG.md
@@ -1,5 +1,34 @@
 # @tanstack/ai-anthropic
 
+## 0.8.4
+
+### Patch Changes
+
+- **Fix thinking blocks getting merged across steps and lost on turn 2+ of Anthropic tool loops.** ([#391](https://github.com/TanStack/ai/pull/391))
+
+  Each thinking step emitted by the adapter now produces its own `ThinkingPart` on the `UIMessage` instead of being merged into a single part, and thinking content + Anthropic signatures are preserved in server-side message history so multi-turn tool flows with extended thinking work correctly.
+
+  This includes a public callback signature change: `StreamProcessorEvents.onThinkingUpdate` now receives `(messageId, stepId, content)` instead of `(messageId, content)`. `ChatClient` has been updated to handle the new `stepId` argument internally, but consumers implementing `StreamProcessorEvents` directly need to add the new parameter.
+
+  `@tanstack/ai`:
+  - `ThinkingPart` gains optional `stepId` and `signature` fields.
+  - `ModelMessage` gains an optional `thinking?: Array<{ content; signature? }>` field so prior thinking can be replayed in subsequent turns.
+  - `StepFinishedEvent` gains an optional `signature` field for provider-supplied thinking signatures.
+  - `StreamProcessor` tracks thinking per-step via `stepId` and keeps step ordering. `getState().thinking` / `getResult().thinking` concatenate step contents in order.
+  - The `onThinkingUpdate` callback on `StreamProcessorEvents` now receives `(messageId, stepId, content)` — consumers implementing it directly must add the `stepId` parameter.
+  - `TextEngine` accumulates thinking + signatures per iteration and includes them in assistant messages with tool calls so the next turn can replay them.
+
+  `@tanstack/ai-anthropic`:
+  - Captures `signature_delta` stream events and emits the final `STEP_FINISHED` with the signature on `content_block_stop`.
+  - Includes thinking blocks with signatures in `formatMessages` for multi-turn history.
+  - Passes `betas: ['interleaved-thinking-2025-05-14']` to the `beta.messages.create` call site when a thinking budget is configured. The beta flag is scoped to the streaming path only, so `structuredOutput` (which uses the non-beta `messages.create` endpoint) is unaffected.
+
+  `@tanstack/ai-client`:
+  - `ChatClient`'s internal `onThinkingUpdate` wiring is updated for the new `stepId` parameter.
+
+- Updated dependencies [[`b2d3cc1`](https://github.com/TanStack/ai/commit/b2d3cc131a31c54bd1e5841f958fbe333514e508)]:
+  - @tanstack/ai@0.15.0
+
 ## 0.8.3
 
 ### Patch Changes

diff --git a/packages/typescript/ai-anthropic/package.json b/packages/typescript/ai-anthropic/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@tanstack/ai-anthropic",
-  "version": "0.8.3",
+  "version": "0.8.4",
   "description": "Anthropic Claude adapter for TanStack AI",
   "author": "",
   "license": "MIT",

diff --git a/packages/typescript/ai-client/CHANGELOG.md b/packages/typescript/ai-client/CHANGELOG.md
@@ -1,5 +1,37 @@
 # @tanstack/ai-client
 
+## 0.9.0
+
+### Minor Changes
+
+- **Fix thinking blocks getting merged across steps and lost on turn 2+ of Anthropic tool loops.** ([#391](https://github.com/TanStack/ai/pull/391))
+
+  Each thinking step emitted by the adapter now produces its own `ThinkingPart` on the `UIMessage` instead of being merged into a single part, and thinking content + Anthropic signatures are preserved in server-side message history so multi-turn tool flows with extended thinking work correctly.
+
+  This includes a public callback signature change: `StreamProcessorEvents.onThinkingUpdate` now receives `(messageId, stepId, content)` instead of `(messageId, content)`. `ChatClient` has been updated to handle the new `stepId` argument internally, but consumers implementing `StreamProcessorEvents` directly need to add the new parameter.
+
+  `@tanstack/ai`:
+  - `ThinkingPart` gains optional `stepId` and `signature` fields.
+  - `ModelMessage` gains an optional `thinking?: Array<{ content; signature? }>` field so prior thinking can be replayed in subsequent turns.
+  - `StepFinishedEvent` gains an optional `signature` field for provider-supplied thinking signatures.
+  - `StreamProcessor` tracks thinking per-step via `stepId` and keeps step ordering. `getState().thinking` / `getResult().thinking` concatenate step contents in order.
+  - The `onThinkingUpdate` callback on `StreamProcessorEvents` now receives `(messageId, stepId, content)` — consumers implementing it directly must add the `stepId` parameter.
+  - `TextEngine` accumulates thinking + signatures per iteration and includes them in assistant messages with tool calls so the next turn can replay them.
+
+  `@tanstack/ai-anthropic`:
+  - Captures `signature_delta` stream events and emits the final `STEP_FINISHED` with the signature on `content_block_stop`.
+  - Includes thinking blocks with signatures in `formatMessages` for multi-turn history.
+  - Passes `betas: ['interleaved-thinking-2025-05-14']` to the `beta.messages.create` call site when a thinking budget is configured. The beta flag is scoped to the streaming path only, so `structuredOutput` (which uses the non-beta `messages.create` endpoint) is unaffected.
+
+  `@tanstack/ai-client`:
+  - `ChatClient`'s internal `onThinkingUpdate` wiring is updated for the new `stepId` parameter.
+
+### Patch Changes
+
+- Updated dependencies [[`b2d3cc1`](https://github.com/TanStack/ai/commit/b2d3cc131a31c54bd1e5841f958fbe333514e508)]:
+  - @tanstack/ai@0.15.0
+  - @tanstack/ai-event-client@0.2.9
+
 ## 0.8.0
 
 ### Minor Changes

diff --git a/packages/typescript/ai-client/package.json b/packages/typescript/ai-client/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@tanstack/ai-client",
-  "version": "0.8.0",
+  "version": "0.9.0",
   "description": "Framework-agnostic headless client for TanStack AI",
   "author": "",
   "license": "MIT",

diff --git a/packages/typescript/ai-code-mode-skills/CHANGELOG.md b/packages/typescript/ai-code-mode-skills/CHANGELOG.md
@@ -1,5 +1,13 @@
 # @tanstack/ai-code-mode-skills
 
+## 0.1.9
+
+### Patch Changes
+
+- Updated dependencies [[`b2d3cc1`](https://github.com/TanStack/ai/commit/b2d3cc131a31c54bd1e5841f958fbe333514e508)]:
+  - @tanstack/ai@0.15.0
+  - @tanstack/ai-code-mode@0.1.9
+
 ## 0.1.8
 
 ### Patch Changes

diff --git a/packages/typescript/ai-code-mode-skills/package.json b/packages/typescript/ai-code-mode-skills/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@tanstack/ai-code-mode-skills",
-  "version": "0.1.8",
+  "version": "0.1.9",
   "description": "Persistent skill library for TanStack AI Code Mode - LLM-created reusable code snippets",
   "author": "",
   "license": "MIT",

diff --git a/packages/typescript/ai-code-mode/CHANGELOG.md b/packages/typescript/ai-code-mode/CHANGELOG.md
@@ -1,5 +1,12 @@
 # @tanstack/ai-code-mode
 
+## 0.1.9
+
+### Patch Changes
+
+- Updated dependencies [[`b2d3cc1`](https://github.com/TanStack/ai/commit/b2d3cc131a31c54bd1e5841f958fbe333514e508)]:
+  - @tanstack/ai@0.15.0
+
 ## 0.1.8
 
 ### Patch Changes

diff --git a/packages/typescript/ai-code-mode/models-eval/CHANGELOG.md b/packages/typescript/ai-code-mode/models-eval/CHANGELOG.md
@@ -1,5 +1,20 @@
 # @tanstack/ai-code-mode-models-eval
 
+## 0.0.13
+
+### Patch Changes
+
+- Updated dependencies [[`b2d3cc1`](https://github.com/TanStack/ai/commit/b2d3cc131a31c54bd1e5841f958fbe333514e508)]:
+  - @tanstack/ai@0.15.0
+  - @tanstack/ai-anthropic@0.8.4
+  - @tanstack/ai-code-mode@0.1.9
+  - @tanstack/ai-gemini@0.10.1
+  - @tanstack/ai-grok@0.7.1
+  - @tanstack/ai-groq@0.1.9
+  - @tanstack/ai-ollama@0.6.11
+  - @tanstack/ai-openai@0.8.3
+  - @tanstack/ai-isolate-node@0.1.9
+
 ## 0.0.12
 
 ### Patch Changes

diff --git a/packages/typescript/ai-code-mode/models-eval/package.json b/packages/typescript/ai-code-mode/models-eval/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@tanstack/ai-code-mode-models-eval",
-  "version": "0.0.12",
+  "version": "0.0.13",
   "private": true,
   "type": "module",
   "description": "Dev benchmark: local/cloud models vs code-mode database-demo gold (not published)",

diff --git a/packages/typescript/ai-code-mode/package.json b/packages/typescript/ai-code-mode/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@tanstack/ai-code-mode",
-  "version": "0.1.8",
+  "version": "0.1.9",
   "description": "Code Mode for TanStack AI - LLM-driven code execution in secure sandboxes",
   "author": "",
   "license": "MIT",

diff --git a/packages/typescript/ai-devtools/CHANGELOG.md b/packages/typescript/ai-devtools/CHANGELOG.md
@@ -1,5 +1,13 @@
 # @tanstack/ai-devtools-core
 
+## 0.3.26
+
+### Patch Changes
+
+- Updated dependencies [[`b2d3cc1`](https://github.com/TanStack/ai/commit/b2d3cc131a31c54bd1e5841f958fbe333514e508)]:
+  - @tanstack/ai@0.15.0
+  - @tanstack/ai-event-client@0.2.9
+
 ## 0.3.25
 
 ### Patch Changes

diff --git a/packages/typescript/ai-devtools/package.json b/packages/typescript/ai-devtools/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@tanstack/ai-devtools-core",
-  "version": "0.3.25",
+  "version": "0.3.26",
   "description": "Core TanStack AI Devtools",
   "author": "",
   "license": "MIT",

diff --git a/packages/typescript/ai-elevenlabs/CHANGELOG.md b/packages/typescript/ai-elevenlabs/CHANGELOG.md
@@ -1,5 +1,13 @@
 # @tanstack/ai-elevenlabs
 
+## 0.2.1
+
+### Patch Changes
+
+- Updated dependencies [[`b2d3cc1`](https://github.com/TanStack/ai/commit/b2d3cc131a31c54bd1e5841f958fbe333514e508)]:
+  - @tanstack/ai@0.15.0
+  - @tanstack/ai-client@0.9.0
+
 ## 0.2.0
 
 ### Minor Changes

diff --git a/packages/typescript/ai-elevenlabs/package.json b/packages/typescript/ai-elevenlabs/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@tanstack/ai-elevenlabs",
-  "version": "0.2.0",
+  "version": "0.2.1",
   "description": "ElevenLabs adapter for TanStack AI realtime voice",
   "author": "",
   "license": "MIT",

diff --git a/packages/typescript/ai-event-client/CHANGELOG.md b/packages/typescript/ai-event-client/CHANGELOG.md
@@ -1,5 +1,12 @@
 # @tanstack/ai-event-client
 
+## 0.2.9
+
+### Patch Changes
+
+- Updated dependencies [[`b2d3cc1`](https://github.com/TanStack/ai/commit/b2d3cc131a31c54bd1e5841f958fbe333514e508)]:
+  - @tanstack/ai@0.15.0
+
 ## 0.2.8
 
 ### Patch Changes

diff --git a/packages/typescript/ai-event-client/package.json b/packages/typescript/ai-event-client/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@tanstack/ai-event-client",
-  "version": "0.2.8",
+  "version": "0.2.9",
   "description": "Event client for TanStack AI devtools integration",
   "author": "",
   "license": "MIT",

diff --git a/packages/typescript/ai-fal/CHANGELOG.md b/packages/typescript/ai-fal/CHANGELOG.md
@@ -1,5 +1,12 @@
 # @tanstack/ai-fal
 
+## 0.7.1
+
+### Patch Changes
+
+- Updated dependencies [[`b2d3cc1`](https://github.com/TanStack/ai/commit/b2d3cc131a31c54bd1e5841f958fbe333514e508)]:
+  - @tanstack/ai@0.15.0
+
 ## 0.7.0
 
 ### Minor Changes

diff --git a/packages/typescript/ai-fal/package.json b/packages/typescript/ai-fal/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@tanstack/ai-fal",
-  "version": "0.7.0",
+  "version": "0.7.1",
   "description": "fal.ai adapter for TanStack AI",
   "author": "",
   "license": "MIT",

diff --git a/packages/typescript/ai-gemini/CHANGELOG.md b/packages/typescript/ai-gemini/CHANGELOG.md
@@ -1,5 +1,12 @@
 # @tanstack/ai-gemini
 
+## 0.10.1
+
+### Patch Changes
+
+- Updated dependencies [[`b2d3cc1`](https://github.com/TanStack/ai/commit/b2d3cc131a31c54bd1e5841f958fbe333514e508)]:
+  - @tanstack/ai@0.15.0
+
 ## 0.10.0
 
 ### Minor Changes

diff --git a/packages/typescript/ai-gemini/package.json b/packages/typescript/ai-gemini/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@tanstack/ai-gemini",
-  "version": "0.10.0",
+  "version": "0.10.1",
   "description": "Google Gemini adapter for TanStack AI",
   "author": "",
   "license": "MIT",

diff --git a/packages/typescript/ai-grok/CHANGELOG.md b/packages/typescript/ai-grok/CHANGELOG.md
@@ -1,5 +1,12 @@
 # @tanstack/ai-grok
 
+## 0.7.1
+
+### Patch Changes
+
+- Updated dependencies [[`b2d3cc1`](https://github.com/TanStack/ai/commit/b2d3cc131a31c54bd1e5841f958fbe333514e508)]:
+  - @tanstack/ai@0.15.0
+
 ## 0.7.0
 
 ### Minor Changes

diff --git a/packages/typescript/ai-grok/package.json b/packages/typescript/ai-grok/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@tanstack/ai-grok",
-  "version": "0.7.0",
+  "version": "0.7.1",
   "description": "Grok (xAI) adapter for TanStack AI",
   "author": "",
   "license": "MIT",