diff --git a/.github/workflows/agentex-tutorials-test.yml b/.github/workflows/agentex-tutorials-test.yml
index 7f2c762dd..19cfc8468 100644
--- a/.github/workflows/agentex-tutorials-test.yml
+++ b/.github/workflows/agentex-tutorials-test.yml
@@ -124,10 +124,13 @@ jobs:
 
       - name: Build AgentEx SDK
         run: |
-          echo "🔨 Building AgentEx SDK wheel..."
-          uv build
-          echo "✅ SDK built successfully"
+          echo "🔨 Building slim agentex-sdk-client wheel (root)..."
+          uv build --wheel
+          echo "🔨 Building heavy agentex-sdk wheel (adk/)..."
+          (cd adk && uv build --wheel)
+          echo "✅ Both SDK wheels built successfully"
           ls -la dist/
+          ls -la adk/dist/
 
       - name: Test Tutorial
         id: run-test
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b29d7f3ab..5d25b41d9 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -32,11 +32,14 @@ jobs:
           RYE_INSTALL_OPTION: '--yes'
 
       - name: Install dependencies
-        run: rye sync --all-features
+        run: ./scripts/bootstrap
 
       - name: Run lints
         run: ./scripts/lint
 
+      - name: Check slim dependency set
+        run: ./scripts/check-slim-deps
+
   build:
     if: (github.event_name == 'push' || github.event.pull_request.head.repo.fork) && (github.event_name != 'push' || github.event.head_commit.message != 'codegen metadata')
     timeout-minutes: 10
@@ -57,10 +60,19 @@ jobs:
           RYE_INSTALL_OPTION: '--yes'
 
       - name: Install dependencies
-        run: rye sync --all-features
+        run: ./scripts/bootstrap
+
+      - name: Run build (slim agentex-sdk-client)
+        # --wheel only: avoid the sdist intermediate step, which would
+        # otherwise force the heavy build below to resolve cross-directory
+        # paths from inside a sdist tarball.
+        run: rye build --wheel
 
-      - name: Run build
-        run: rye build
+      - name: Run build (ADK overlay agentex-sdk)
+        # Heavy wheel uses hatchling force-include to pull
+        # ../src/agentex/lib into agentex/lib. Building --wheel directly
+        # (vs sdist-then-wheel) keeps the relative path resolvable.
+        run: (cd adk && rye build --wheel)
 
       - name: Get GitHub OIDC Token
         if: |-
diff --git a/.github/workflows/publish-pypi.yml b/.github/workflows/publish-pypi.yml
index 864901da6..adbf317d4 100644
--- a/.github/workflows/publish-pypi.yml
+++ b/.github/workflows/publish-pypi.yml
@@ -28,4 +28,11 @@ jobs:
         run: |
           bash ./bin/publish-pypi
         env:
+          # Heavy `agentex-sdk` package token (existing PyPI name).
+          AGENTEX_PYPI_TOKEN: ${{ secrets.AGENTEX_PYPI_TOKEN }}
+          # Slim `agentex-sdk-client` package token (new PyPI name; needs
+          # to be added to repo secrets when the slim is registered).
+          AGENTEX_SDK_CLIENT_PYPI_TOKEN: ${{ secrets.AGENTEX_SDK_CLIENT_PYPI_TOKEN }}
+          # Back-compat fallback — used by bin/publish-pypi when the
+          # dedicated tokens above are unset.
           PYPI_TOKEN: ${{ secrets.AGENTEX_PYPI_TOKEN || secrets.PYPI_TOKEN }}
diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 5a36a4131..e31704a76 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,4 @@
 {
-  ".": "0.11.5"
+  ".": "0.11.5",
+  "adk": "0.11.5"
 }
diff --git a/adk/README.md b/adk/README.md
new file mode 100644
index 000000000..d3f5e6d8f
--- /dev/null
+++ b/adk/README.md
@@ -0,0 +1,32 @@
+# agentex-sdk
+
+The Agent Development Kit (ADK) overlay for the Agentex API.
+
+## What's in here
+
+This package ships everything under `agentex.lib.*`:
+
+- **ACP server** (`agentex.lib.sdk.fastacp`) — FastAPI-based agent control plane.
+- **Temporal workflows** (`agentex.lib.core.temporal`) — durable agent execution.
+- **CLI** (`agentex.lib.cli`) — `agentex init`, `agentex run`, deploy helpers.
+- **LLM provider integrations** (`agentex.lib.adk.providers`, `agentex.lib.core.temporal.plugins`) — OpenAI Agents, Claude Agent SDK, pydantic-ai, langgraph, litellm.
+- **Observability** (`agentex.lib.core.tracing`, `agentex.lib.core.observability`) — SGP, Datadog, OpenTelemetry tracing processors.
+
+## Installation
+
+```sh
+pip install agentex-sdk
+```
+
+This automatically pulls in [`agentex-sdk-client`](../) (the slim Stainless-generated REST client) so `from agentex import Agentex, AsyncAgentex` works the same as before.
+
+## When to use this vs `agentex-sdk-client`
+
+- **`agentex-sdk`** — you're authoring agents. Pulls everything: ACP server, Temporal, MCP, LLM providers, observability, CLI. ~37 deps.
+- **`agentex-sdk-client`** — you only need to call the Agentex REST API. No agent authoring, no Temporal workflows, no FastACP server, no provider integrations. 6 deps.
+
+The two packages contribute disjoint files to the `agentex.*` namespace — `agentex/lib/*` ships only from `agentex-sdk`.
+
+## Repo layout
+
+This package is hand-authored and lives at `adk/` inside [scaleapi/scale-agentex-python](https://github.com/scaleapi/scale-agentex-python). The Stainless generator preserves `adk/**` via `keep_files` so its codegen never touches anything here. The sibling `agentex-sdk-client` package lives at the repo root and IS Stainless-generated.
diff --git a/adk/hatch_build.py b/adk/hatch_build.py
new file mode 100644
index 000000000..8baadfe5b
--- /dev/null
+++ b/adk/hatch_build.py
@@ -0,0 +1,41 @@
+"""Builds the agentex/lib force-include map per-file so test files can be pruned
+— force-include ignores `exclude` (hatchling #1395)."""
+
+from __future__ import annotations
+
+import os
+
+from hatchling.builders.hooks.plugin.interface import BuildHookInterface
+
+_SKIP_DIRS = {"__pycache__", "tests"}
+_SKIP_NAMES = {"conftest.py", "pytest.ini", "run_tests.py"}
+# Floor below the ~333 shippable files: a collapse means the walk broke — fail
+# loud rather than ship a near-empty wheel.
+_MIN_FILES = 320
+
+
+def _is_test_file(name: str) -> bool:
+    return name in _SKIP_NAMES or (name.startswith("test_") and name.endswith(".py"))
+
+
+class CustomBuildHook(BuildHookInterface):
+    PLUGIN_NAME = "custom"
+
+    def initialize(self, version: str, build_data: dict) -> None:  # noqa: ARG002
+        lib_root = os.path.normpath(os.path.join(self.root, "..", "src", "agentex", "lib"))
+        force_include = build_data.setdefault("force_include", {})
+        collected = 0
+        for dirpath, dirnames, filenames in os.walk(lib_root):
+            dirnames[:] = [d for d in dirnames if d not in _SKIP_DIRS]
+            for name in filenames:
+                if _is_test_file(name):
+                    continue
+                src = os.path.join(dirpath, name)
+                rel = os.path.relpath(src, lib_root)
+                force_include[src] = os.path.join("agentex", "lib", rel)
+                collected += 1
+        if collected < _MIN_FILES:
+            raise RuntimeError(
+                f"agentex/lib force-include collected only {collected} files "
+                f"(expected >= {_MIN_FILES}); aborting build."
+            )
diff --git a/adk/pyproject.toml b/adk/pyproject.toml
new file mode 100644
index 000000000..48f238295
--- /dev/null
+++ b/adk/pyproject.toml
@@ -0,0 +1,105 @@
+[project]
+# Hand-authored ADK overlay for agentex. This package contributes only
+# `agentex/lib/*` to the agentex.* namespace; the REST client surface
+# (agentex/{__init__.py, _*.py, types/, resources/}) ships from the slim
+# sibling package `agentex-sdk-client` which is pinned as a runtime dep.
+#
+# This entire `adk/` directory must be preserved across Stainless codegen
+# via `keep_files: ["adk/**"]` in the Stainless dashboard config.
+name = "agentex-sdk"
+version = "0.11.5"
+description = "Agent Development Kit (ADK) overlay for the Agentex API — FastACP server, Temporal workflows, LLM provider integrations, observability"
+license = "Apache-2.0"
+authors = [
+  { name = "Agentex", email = "roxanne.farhad@scale.com" },
+]
+readme = "README.md"
+
+dependencies = [
+    # Co-released in lockstep; floor-only by design — a ceiling would
+    # eventually exclude the co-versioned slim (release-please can't bump it).
+    "agentex-sdk-client>=0.11.5",
+    # CLI surface (agentex.lib.cli.*, agentex.lib.sdk.config.*)
+    "typer>=0.16,<0.17",
+    "questionary>=2.0.1,<3",
+    "rich>=13.9.2,<14",
+    "yaspin>=3.1.0",
+    "pyyaml>=6.0.2,<7",
+    "python-on-whales>=0.73.0,<0.74",
+    "kubernetes>=25.0.0,<36.0.0",
+    "jsonref>=1.1.0,<2",
+    "jsonschema>=4.23.0,<5",
+    "jinja2>=3.1.3,<4",
+    "watchfiles>=0.24.0,<1.0",
+    # ACP server (FastAPI app surface)
+    "fastapi>=0.115.0",
+    "starlette>=0.49.1",
+    "uvicorn>=0.31.1",
+    "aiohttp>=3.10.10,<4",
+    # Temporal workflows
+    "temporalio>=1.26.0,<2",
+    "cloudpickle>=3.1.1",
+    # Async streaming infra
+    "redis>=5.2.0,<8",
+    # LLM provider integrations
+    "litellm>=1.83.7,<2",
+    "openai-agents>=0.14.3,<0.15",
+    "openai>=2.2,<3", # Required by openai-agents; litellm now supports openai 2.x (issue #13711 resolved: https://github.com/BerriAI/litellm/issues/13711)
+    "claude-agent-sdk>=0.1.0",
+    "pydantic-ai-slim>=1.0,<2",
+    "langgraph-checkpoint>=2.0.0",
+    "scale-gp>=0.1.0a59",
+    "scale-gp-beta>=0.2.0",
+    "mcp>=1.4.1",
+    # Observability
+    "ddtrace>=3.13.0",
+    "opentelemetry-api>=1.20.0",
+    "opentelemetry-sdk>=1.20.0",
+    "json_log_formatter>=1.1.1",
+]
+
+# agentex/lib/* uses `from typing import override` (3.12+) in 19 files.
+# The slim agentex-sdk-client keeps 3.11 support.
+requires-python = ">= 3.12,<4"
+classifiers = [
+  "Typing :: Typed",
+  "Intended Audience :: Developers",
+  "Programming Language :: Python :: 3.12",
+  "Programming Language :: Python :: 3.13",
+  "Programming Language :: Python :: 3.14",
+  "Operating System :: OS Independent",
+  "Topic :: Software Development :: Libraries :: Python Modules",
+  "License :: OSI Approved :: Apache Software License",
+]
+
+[project.urls]
+Homepage = "https://github.com/scaleapi/scale-agentex-python"
+Repository = "https://github.com/scaleapi/scale-agentex-python"
+
+[project.scripts]
+agentex = "agentex.lib.cli.commands.main:app"
+
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+# Ship only agentex/lib/*, pulled in from the parent repo's `src/agentex/lib`
+# tree. The rest of agentex.* (the Stainless-generated client) ships from the
+# sibling agentex-sdk-client package, which this package pins as a runtime dep.
+# Stainless explicitly preserves `src/agentex/lib/` across codegen (per
+# CONTRIBUTING.md), so it's safe to keep the source where it is.
+[tool.hatch.build.targets.wheel]
+bypass-selection = true
+
+# Builds the ../src/agentex/lib force-include map per-file (see hatch_build.py)
+# so test files can be pruned — force-include ignores `exclude` (hatchling #1395).
+[tool.hatch.build.targets.wheel.hooks.custom]
+path = "hatch_build.py"
+
+# Sdist deferred: hatchling can't represent the wheel's ../src/agentex/lib
+# force-include in an sdist include list. CI + bin/publish-pypi pass --wheel.
+[tool.hatch.build.targets.sdist]
+include = [
+  "/pyproject.toml",
+  "/README.md",
+]
diff --git a/bin/check-release-environment b/bin/check-release-environment
index b845b0f4c..7b8488507 100644
--- a/bin/check-release-environment
+++ b/bin/check-release-environment
@@ -1,9 +1,21 @@
 #!/usr/bin/env bash
 
+# This script is run by Release Doctor to validate the release environment.
+# After the dual-package split (slim agentex-sdk-client + heavy agentex-sdk),
+# both PyPI tokens must be present — one for each package name. If only
+# PYPI_TOKEN is set, fall back to using it for both (back-compat for legacy
+# single-token setups, which forces an account-scoped token).
+
 errors=()
 
-if [ -z "${PYPI_TOKEN}" ]; then
-  errors+=("The PYPI_TOKEN secret has not been set. Please set it in either this repository's secrets or your organization secrets.")
+# Heavy `agentex-sdk` token (existing PyPI name).
+if [ -z "${AGENTEX_PYPI_TOKEN}" ] && [ -z "${PYPI_TOKEN}" ]; then
+  errors+=("The AGENTEX_PYPI_TOKEN secret has not been set (and no fallback PYPI_TOKEN). Add it in repo secrets so the heavy 'agentex-sdk' package can be published.")
+fi
+
+# Slim `agentex-sdk-client` token (new PyPI name).
+if [ -z "${AGENTEX_SDK_CLIENT_PYPI_TOKEN}" ] && [ -z "${PYPI_TOKEN}" ]; then
+  errors+=("The AGENTEX_SDK_CLIENT_PYPI_TOKEN secret has not been set (and no fallback PYPI_TOKEN). Add it in repo secrets so the slim 'agentex-sdk-client' package can be published. Falling back to PYPI_TOKEN requires an account-scoped token.")
 fi
 
 lenErrors=${#errors[@]}
diff --git a/bin/publish-pypi b/bin/publish-pypi
index 826054e92..5a3486a32 100644
--- a/bin/publish-pypi
+++ b/bin/publish-pypi
@@ -1,6 +1,35 @@
 #!/usr/bin/env bash
 
+# Publish both the Stainless-managed slim `agentex-sdk-client` package (built
+# from this repo's root) and the hand-authored `agentex-sdk` ADK overlay
+# (built from adk/). The two packages contribute disjoint files to the same
+# `agentex.*` namespace; `agentex-sdk` pins `agentex-sdk-client` as a runtime
+# dep so installing `agentex-sdk` transitively pulls in the slim client.
+#
+# Publish ORDER matters: slim first, then heavy. Heavy's dep on slim means
+# anyone installing `agentex-sdk` hits resolver failure if slim hasn't shipped
+# yet. Failing the slim publish before the heavy gives us a chance to abort
+# without leaving an inconsistent registry state.
+#
+# Tokens:
+#   - $AGENTEX_SDK_CLIENT_PYPI_TOKEN — auths publishing the slim client
+#   - $AGENTEX_PYPI_TOKEN (alias $PYPI_TOKEN for back-compat) — auths
+#     publishing the heavy ADK overlay (which continues to claim the
+#     `agentex-sdk` name on PyPI)
+
 set -eux
+
+# Slim Stainless-managed client (root) — `agentex-sdk-client` on PyPI.
 mkdir -p dist
-rye build --clean
-rye publish --yes --token=$PYPI_TOKEN
+rye build --clean --wheel  # --wheel: sdist deferred (see adk/pyproject.toml).
+rye publish --yes --skip-existing --token="${AGENTEX_SDK_CLIENT_PYPI_TOKEN:-$PYPI_TOKEN}"
+
+# Heavy ADK overlay (adk/) — `agentex-sdk` on PyPI; pins the slim above.
+(
+  cd adk
+  mkdir -p dist
+  # --wheel load-bearing: rye's sdist-then-wheel default can't resolve
+  # the force-include of ../src/agentex/lib → silent empty wheel.
+  rye build --clean --wheel
+  rye publish --yes --skip-existing --token="${AGENTEX_PYPI_TOKEN:-$PYPI_TOKEN}"
+)
diff --git a/examples/tutorials/run_agent_test.sh b/examples/tutorials/run_agent_test.sh
index c6fd17960..8d0912d6f 100755
--- a/examples/tutorials/run_agent_test.sh
+++ b/examples/tutorials/run_agent_test.sh
@@ -126,18 +126,26 @@ start_agent() {
 
     if [ "$BUILD_CLI" = true ]; then
 
-        # Use wheel from dist directory at repo root
-        local wheel_file=$(ls /home/runner/work/*/*/dist/agentex_sdk-*.whl 2>/dev/null | head -n1)
-        if [[ -z "$wheel_file" ]]; then
-            echo -e "${RED}❌ No built wheel found in dist/agentex_sdk-*.whl${NC}"
-            echo -e "${YELLOW}💡 Please build the local SDK first by running: uv build${NC}"
-            echo -e "${YELLOW}💡 From the repo root directory${NC}"
+        # Heavy ADK wheel ships from adk/dist/; slim client wheel ships from dist/.
+        # We need both: heavy pins agentex-sdk-client which isn't on PyPI yet,
+        # so uv must resolve both from local wheels rather than the registry.
+        local heavy_wheel=$(ls /home/runner/work/*/*/adk/dist/agentex_sdk-*.whl 2>/dev/null | head -n1)
+        local slim_wheel=$(ls /home/runner/work/*/*/dist/agentex_sdk_client-*.whl 2>/dev/null | head -n1)
+        if [[ -z "$heavy_wheel" ]]; then
+            echo -e "${RED}❌ No built heavy wheel found in adk/dist/agentex_sdk-*.whl${NC}"
+            echo -e "${YELLOW}💡 Build it first: (cd adk && uv build --wheel)${NC}"
+            cd "$original_dir"
+            return 1
+        fi
+        if [[ -z "$slim_wheel" ]]; then
+            echo -e "${RED}❌ No built slim wheel found in dist/agentex_sdk_client-*.whl${NC}"
+            echo -e "${YELLOW}💡 Build it first: uv build --wheel${NC}"
             cd "$original_dir"
             return 1
         fi
 
-        # Use the built wheel
-        uv run --with "$wheel_file" agentex agents run --manifest "$manifest_path" > "$logfile" 2>&1 &
+        # Pass both wheels so the local heavy resolves its slim dep locally
+        uv run --with "$heavy_wheel" --with "$slim_wheel" agentex agents run --manifest "$manifest_path" > "$logfile" 2>&1 &
     else
         uv run agentex agents run --manifest manifest.yaml > "$logfile" 2>&1 &
     fi
@@ -269,14 +277,20 @@ run_test() {
     # robust across all tutorials regardless of how each declares test deps.
     local -a pytest_cmd=("uv" "run" "--with" "pytest" "--with" "pytest-asyncio" "pytest")
     if [ "$BUILD_CLI" = true ]; then
-        local wheel_file
-        wheel_file=$(ls /home/runner/work/*/*/dist/agentex_sdk-*.whl 2>/dev/null | head -n1)
-        if [[ -z "$wheel_file" ]]; then
-            wheel_file=$(ls "${SCRIPT_DIR}/../../dist/agentex_sdk-*.whl" 2>/dev/null | head -n1)
+        local heavy_wheel slim_wheel
+        heavy_wheel=$(ls /home/runner/work/*/*/adk/dist/agentex_sdk-*.whl 2>/dev/null | head -n1)
+        if [[ -z "$heavy_wheel" ]]; then
+            heavy_wheel=$(ls "${SCRIPT_DIR}"/../../adk/dist/agentex_sdk-*.whl 2>/dev/null | head -n1)
+        fi
+        slim_wheel=$(ls /home/runner/work/*/*/dist/agentex_sdk_client-*.whl 2>/dev/null | head -n1)
+        if [[ -z "$slim_wheel" ]]; then
+            slim_wheel=$(ls "${SCRIPT_DIR}"/../../dist/agentex_sdk_client-*.whl 2>/dev/null | head -n1)
         fi
-        if [[ -n "$wheel_file" ]]; then
-            pytest_cmd=("uv" "run" "--with" "$wheel_file" "--with" "pytest" "--with" "pytest-asyncio" "pytest")
+        if [[ -z "$heavy_wheel" || -z "$slim_wheel" ]]; then
+            echo -e "${RED}❌ BUILD_CLI=true but a wheel is missing (heavy='${heavy_wheel}' slim='${slim_wheel}'); refusing to test against the pre-installed SDK${NC}"
+            return 1
         fi
+        pytest_cmd=("uv" "run" "--with" "$heavy_wheel" "--with" "$slim_wheel" "--with" "pytest" "--with" "pytest-asyncio" "pytest")
     fi
 
     local max_retries=5
@@ -350,7 +364,7 @@ execute_tutorial_test() {
     fi
 }
 
-# Function to check if built wheel is available
+# Function to check if both built wheels are available
 check_built_wheel() {
 
     # Navigate to the repo root (two levels up from examples/tutorials)
@@ -362,19 +376,26 @@ check_built_wheel() {
         return 1
     }
 
-    # Check if wheel exists in dist directory at repo root
-    local wheel_file=$(ls /home/runner/work/*/*/dist/agentex_sdk-*.whl 2>/dev/null | head -n1)
-    if [[ -z "$wheel_file" ]]; then
-        echo -e "${RED}❌ No built wheel found in dist/agentex_sdk-*.whl${NC}"
-        echo -e "${YELLOW}💡 Please build the local SDK first by running: uv build${NC}"
-        echo -e "${YELLOW}💡 From the repo root directory${NC}"
+    # Heavy ADK wheel + slim client wheel — we need both because heavy pins
+    # agentex-sdk-client which isn't on PyPI yet.
+    local heavy_wheel=$(ls /home/runner/work/*/*/adk/dist/agentex_sdk-*.whl 2>/dev/null | head -n1)
+    local slim_wheel=$(ls /home/runner/work/*/*/dist/agentex_sdk_client-*.whl 2>/dev/null | head -n1)
+    if [[ -z "$heavy_wheel" ]]; then
+        echo -e "${RED}❌ No built heavy wheel found in adk/dist/agentex_sdk-*.whl${NC}"
+        echo -e "${YELLOW}💡 Build it first: (cd adk && uv build --wheel)${NC}"
+        cd "$original_dir"
+        return 1
+    fi
+    if [[ -z "$slim_wheel" ]]; then
+        echo -e "${RED}❌ No built slim wheel found in dist/agentex_sdk_client-*.whl${NC}"
+        echo -e "${YELLOW}💡 Build it first: uv build --wheel${NC}"
         cd "$original_dir"
         return 1
     fi
 
-    # Test the wheel by running agentex --help
-    if ! uv run --with "$wheel_file" agentex --help >/dev/null 2>&1; then
-        echo -e "${RED}❌ Failed to run agentex with built wheel${NC}"
+    # Test the heavy wheel by running agentex --help (uses both wheels for resolution)
+    if ! uv run --with "$heavy_wheel" --with "$slim_wheel" agentex --help >/dev/null 2>&1; then
+        echo -e "${RED}❌ Failed to run agentex with built wheels${NC}"
         cd "$original_dir"
         return 1
     fi
diff --git a/pyproject.toml b/pyproject.toml
index 7cf27ff4e..ac85b3701 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,15 @@
 [project]
-name = "agentex-sdk"
+# This is the Stainless-generated REST client. The hand-authored ADK
+# overlay (formerly `src/agentex/lib/*`) now lives in `adk/` and ships
+# as the sibling `agentex-sdk` package — see `adk/pyproject.toml`.
+#
+# Stainless dashboard config must:
+#   - Rename `package_name` from `agentex-sdk` to `agentex-sdk-client`
+#   - Reduce the dep list to the 6 bare-client deps below
+#   - Add `adk/**` to `keep_files` so the ADK overlay persists across codegen
+name = "agentex-sdk-client"
 version = "0.11.5"
-description = "The official Python library for the agentex API"
+description = "The official Python REST client for the Agentex API"
 dynamic = ["readme"]
 license = "Apache-2.0"
 authors = [
@@ -15,37 +23,6 @@ dependencies = [
     "anyio>=3.5.0, <5",
     "distro>=1.7.0, <2",
     "sniffio",
-    "typer>=0.16,<0.17",
-    "questionary>=2.0.1,<3",
-    "rich>=13.9.2,<14",
-    "fastapi>=0.115.0",
-    "starlette>=0.49.1",
-    "uvicorn>=0.31.1",
-    "watchfiles>=0.24.0,<1.0",
-    "python-on-whales>=0.73.0,<0.74",
-    "pyyaml>=6.0.2,<7",
-    "jsonschema>=4.23.0,<5",
-    "jsonref>=1.1.0,<2",
-    "temporalio>=1.26.0,<2",
-    "aiohttp>=3.10.10,<4",
-    "redis>=5.2.0,<8",
-    "litellm>=1.83.7,<2",
-    "kubernetes>=25.0.0,<36.0.0",
-    "jinja2>=3.1.3,<4",
-    "mcp>=1.4.1",
-    "scale-gp>=0.1.0a59",
-    "openai-agents>=0.14.3,<0.15",
-    "pydantic-ai-slim>=1.0,<2",
-    "json_log_formatter>=1.1.1",
-    "scale-gp-beta>=0.2.0",
-    "openai>=2.2,<3", # Required by openai-agents; litellm now supports openai 2.x (issue #13711 resolved: https://github.com/BerriAI/litellm/issues/13711)
-    "cloudpickle>=3.1.1",
-    "ddtrace>=3.13.0",
-    "yaspin>=3.1.0",
-    "claude-agent-sdk>=0.1.0",
-    "langgraph-checkpoint>=2.0.0",
-    "opentelemetry-sdk>=1.20.0",
-    "opentelemetry-api>=1.20.0",
 ]
 
 requires-python = ">= 3.11,<4"
@@ -75,8 +52,14 @@ dev = [
     "ruff>=0.3.4",
 ]
 
-[project.scripts]
-agentex = "agentex.lib.cli.commands.main:app"
+# The `agentex` CLI entry point ships from the ADK package — see
+# `adk/pyproject.toml`. The slim client has no CLI surface.
+
+[tool.rye.workspace]
+# `rye sync` from the root installs both this slim package and the ADK
+# overlay editably. `src/agentex/lib/` is shared source: the slim wheel
+# excludes it; the heavy wheel includes it via hatchling force-include.
+members = ["adk"]
 
 [tool.rye]
 managed = true
@@ -144,13 +127,11 @@ include = [
 
 [tool.hatch.build.targets.wheel]
 packages = ["src/agentex"]
-# Don't ship internal test files in the wheel. `lib/cli/templates/**/test_agent.py.j2`
-# is intentionally kept — those render into user projects.
+# agentex/lib/* ships from the sibling agentex-sdk package (see adk/pyproject.toml).
+# Excluding it here keeps the slim wheel disjoint from the heavy wheel so both
+# can install into the same site-packages/agentex/ without file conflicts.
 exclude = [
-  "src/agentex/lib/**/tests/**",
-  "src/agentex/lib/**/test_*.py",
-  "src/agentex/lib/**/conftest.py",
-  "src/agentex/lib/**/pytest.ini",
+  "src/agentex/lib/**",
 ]
 
 [tool.hatch.build.targets.sdist]
@@ -205,6 +186,8 @@ exclude = [
     # Exclude autogenerated Stainless code from type checking
     "src/agentex/resources",
     "src/agentex/types",
+    # Build-time hook; imports hatchling, a build dep absent from the synced env.
+    "adk/hatch_build.py",
 ]
 
 reportImplicitOverride = true
diff --git a/release-please-config.json b/release-please-config.json
index 52d4c546d..d49b37199 100644
--- a/release-please-config.json
+++ b/release-please-config.json
@@ -1,10 +1,18 @@
 {
   "packages": {
-    ".": {}
+    ".": {
+      "component": "agentex-sdk-client",
+      "extra-files": [
+        "src/agentex/_version.py"
+      ]
+    },
+    "adk": {
+      "component": "agentex-sdk"
+    }
   },
   "$schema": "https://raw.githubusercontent.com/stainless-api/release-please/main/schemas/config.json",
   "include-v-in-tag": true,
-  "include-component-in-tag": false,
+  "include-component-in-tag": true,
   "versioning": "prerelease",
   "prerelease": true,
   "bump-minor-pre-major": true,
@@ -59,8 +67,5 @@
       "hidden": true
     }
   ],
-  "release-type": "python",
-  "extra-files": [
-    "src/agentex/_version.py"
-  ]
+  "release-type": "python"
 }
\ No newline at end of file
diff --git a/requirements-dev.lock b/requirements-dev.lock
index dc7ee59b8..f1473c57d 100644
--- a/requirements-dev.lock
+++ b/requirements-dev.lock
@@ -10,10 +10,13 @@
 #   universal: false
 
 -e file:.
+    # via agentex-sdk
+-e file:adk
 aiohappyeyeballs==2.6.1
     # via aiohttp
 aiohttp==3.13.5
     # via agentex-sdk
+    # via agentex-sdk-client
     # via httpx-aiohttp
     # via litellm
 aiosignal==1.4.0
@@ -22,11 +25,8 @@ annotated-doc==0.0.4
     # via fastapi
 annotated-types==0.7.0
     # via pydantic
-anthropic==0.86.0
-    # via agentex-sdk
 anyio==4.12.1
-    # via agentex-sdk
-    # via anthropic
+    # via agentex-sdk-client
     # via claude-agent-sdk
     # via httpx
     # via mcp
@@ -36,12 +36,8 @@ anyio==4.12.1
     # via sse-starlette
     # via starlette
     # via watchfiles
-appnope==0.1.4
-    # via ipykernel
 argcomplete==3.6.3
     # via nox
-asttokens==3.0.1
-    # via stack-data
 attrs==25.4.0
     # via aiohttp
     # via jsonschema
@@ -68,38 +64,26 @@ cloudpickle==3.1.2
     # via agentex-sdk
 colorlog==6.10.1
     # via nox
-comm==0.2.3
-    # via ipykernel
 cryptography==46.0.6
     # via google-auth
     # via pyjwt
-datadog==0.52.1
-    # via agentex-sdk
 ddtrace==4.6.4
     # via agentex-sdk
 debugpy==1.8.20
-    # via ipykernel
-decorator==5.2.1
-    # via ipython
 dependency-groups==1.3.1
     # via nox
 dirty-equals==0.11
 distlib==0.4.0
     # via virtualenv
 distro==1.9.0
-    # via agentex-sdk
-    # via anthropic
+    # via agentex-sdk-client
     # via openai
     # via scale-gp
     # via scale-gp-beta
-docstring-parser==0.17.0
-    # via anthropic
 envier==0.6.1
     # via ddtrace
 execnet==2.1.2
     # via pytest-xdist
-executing==2.2.1
-    # via stack-data
 fastapi==0.136.1
     # via agentex-sdk
 fastuuid==0.14.0
@@ -127,8 +111,7 @@ hf-xet==1.4.2
 httpcore==1.0.9
     # via httpx
 httpx==0.28.1
-    # via agentex-sdk
-    # via anthropic
+    # via agentex-sdk-client
     # via genai-prices
     # via httpx-aiohttp
     # via huggingface-hub
@@ -142,7 +125,7 @@ httpx==0.28.1
     # via scale-gp
     # via scale-gp-beta
 httpx-aiohttp==0.1.12
-    # via agentex-sdk
+    # via agentex-sdk-client
 httpx-sse==0.4.3
     # via mcp
 huggingface-hub==1.8.0
@@ -159,19 +142,10 @@ importlib-metadata==8.5.0
     # via opentelemetry-api
 iniconfig==2.1.0
     # via pytest
-ipykernel==7.2.0
-    # via agentex-sdk
-ipython==9.12.0
-    # via ipykernel
-ipython-pygments-lexers==1.1.1
-    # via ipython
-jedi==0.19.2
-    # via ipython
 jinja2==3.1.6
     # via agentex-sdk
     # via litellm
 jiter==0.13.0
-    # via anthropic
     # via openai
 json-log-formatter==1.1.1
     # via agentex-sdk
@@ -187,11 +161,6 @@ jsonschema==4.23.0
     # via mcp
 jsonschema-specifications==2025.9.1
     # via jsonschema
-jupyter-client==8.8.0
-    # via ipykernel
-jupyter-core==5.9.1
-    # via ipykernel
-    # via jupyter-client
 kubernetes==28.1.0
     # via agentex-sdk
 langchain-core==1.2.23
@@ -208,9 +177,6 @@ markdown-it-py==3.0.0
     # via rich
 markupsafe==3.0.3
     # via jinja2
-matplotlib-inline==0.2.1
-    # via ipykernel
-    # via ipython
 mcp==1.26.0
     # via agentex-sdk
     # via claude-agent-sdk
@@ -224,7 +190,6 @@ mypy==1.17.0
 mypy-extensions==1.1.0
     # via mypy
 nest-asyncio==1.6.0
-    # via ipykernel
 nexus-rpc==1.4.0
     # via temporalio
 nodeenv==1.10.0
@@ -256,36 +221,23 @@ ormsgpack==1.12.2
 packaging==25.0
     # via dependency-groups
     # via huggingface-hub
-    # via ipykernel
     # via langchain-core
     # via langsmith
     # via nox
     # via pytest
-parso==0.8.6
-    # via jedi
 pathspec==1.0.3
     # via mypy
-pexpect==4.9.0
-    # via ipython
 platformdirs==4.4.0
-    # via jupyter-core
     # via virtualenv
 pluggy==1.6.0
     # via pytest
 prompt-toolkit==3.0.52
-    # via ipython
     # via questionary
 propcache==0.4.1
     # via aiohttp
     # via yarl
 protobuf==6.33.6
     # via temporalio
-psutil==7.2.2
-    # via ipykernel
-ptyprocess==0.7.0
-    # via pexpect
-pure-eval==0.2.3
-    # via stack-data
 pyasn1==0.6.3
     # via pyasn1-modules
 pyasn1-modules==0.4.2
@@ -293,8 +245,7 @@ pyasn1-modules==0.4.2
 pycparser==3.0
     # via cffi
 pydantic==2.12.5
-    # via agentex-sdk
-    # via anthropic
+    # via agentex-sdk-client
     # via fastapi
     # via genai-prices
     # via langchain-core
@@ -318,27 +269,21 @@ pydantic-graph==1.101.0
 pydantic-settings==2.13.1
     # via mcp
 pygments==2.19.2
-    # via ipython
-    # via ipython-pygments-lexers
     # via pytest
     # via rich
 pyjwt==2.12.1
     # via mcp
 pyright==1.1.399
 pytest==8.4.2
-    # via agentex-sdk
     # via pytest-asyncio
     # via pytest-xdist
 pytest-asyncio==1.2.0
-    # via agentex-sdk
 pytest-xdist==3.8.0
 python-dateutil==2.9.0.post0
-    # via jupyter-client
     # via kubernetes
     # via time-machine
 python-dotenv==1.0.1
     # via litellm
-    # via mcp
     # via pydantic-settings
 python-multipart==0.0.22
     # via mcp
@@ -349,9 +294,6 @@ pyyaml==6.0.3
     # via huggingface-hub
     # via kubernetes
     # via langchain-core
-pyzmq==27.1.0
-    # via ipykernel
-    # via jupyter-client
 questionary==2.1.1
     # via agentex-sdk
 redis==7.4.0
@@ -362,7 +304,6 @@ referencing==0.37.0
 regex==2026.3.32
     # via tiktoken
 requests==2.33.1
-    # via datadog
     # via kubernetes
     # via langsmith
     # via openai-agents
@@ -382,7 +323,7 @@ rpds-py==0.30.0
     # via jsonschema
     # via referencing
 ruff==0.14.13
-    # via agentex-sdk
+    # via agentex-sdk-client
 scale-gp==0.1.0a61
     # via agentex-sdk
 scale-gp-beta==0.2.0
@@ -393,15 +334,12 @@ six==1.17.0
     # via kubernetes
     # via python-dateutil
 sniffio==1.3.1
-    # via agentex-sdk
-    # via anthropic
+    # via agentex-sdk-client
     # via openai
     # via scale-gp
     # via scale-gp-beta
 sse-starlette==3.0.3
     # via mcp
-stack-data==0.6.3
-    # via ipython
 starlette==1.0.0
     # via agentex-sdk
     # via fastapi
@@ -417,24 +355,13 @@ tiktoken==0.12.0
 time-machine==2.19.0
 tokenizers==0.22.2
     # via litellm
-tornado==6.5.5
-    # via agentex-sdk
-    # via ipykernel
-    # via jupyter-client
 tqdm==4.67.3
     # via huggingface-hub
     # via openai
     # via python-on-whales
-traitlets==5.14.3
-    # via ipykernel
-    # via ipython
-    # via jupyter-client
-    # via jupyter-core
-    # via matplotlib-inline
 typer==0.16.1
     # via agentex-sdk
     # via huggingface-hub
-    # via mcp
     # via python-on-whales
 types-protobuf==6.32.1.20260221
     # via temporalio
@@ -443,9 +370,8 @@ types-requests==2.31.0.6
 types-urllib3==1.26.25.14
     # via types-requests
 typing-extensions==4.15.0
-    # via agentex-sdk
+    # via agentex-sdk-client
     # via aiosignal
-    # via anthropic
     # via anyio
     # via fastapi
     # via huggingface-hub
@@ -477,10 +403,6 @@ typing-inspection==0.4.2
     # via pydantic-ai-slim
     # via pydantic-graph
     # via pydantic-settings
-tzdata==2025.3
-    # via agentex-sdk
-tzlocal==5.3.1
-    # via agentex-sdk
 urllib3==1.26.20
     # via kubernetes
     # via requests
diff --git a/requirements.lock b/requirements.lock
index daea78837..3be4368aa 100644
--- a/requirements.lock
+++ b/requirements.lock
@@ -10,10 +10,13 @@
 #   universal: false
 
 -e file:.
+    # via agentex-sdk
+-e file:adk
 aiohappyeyeballs==2.6.1
     # via aiohttp
 aiohttp==3.13.5
     # via agentex-sdk
+    # via agentex-sdk-client
     # via httpx-aiohttp
     # via litellm
 aiosignal==1.4.0
@@ -22,11 +25,8 @@ annotated-doc==0.0.4
     # via fastapi
 annotated-types==0.7.0
     # via pydantic
-anthropic==0.86.0
-    # via agentex-sdk
 anyio==4.12.1
-    # via agentex-sdk
-    # via anthropic
+    # via agentex-sdk-client
     # via claude-agent-sdk
     # via httpx
     # via mcp
@@ -36,10 +36,6 @@ anyio==4.12.1
     # via sse-starlette
     # via starlette
     # via watchfiles
-appnope==0.1.4
-    # via ipykernel
-asttokens==3.0.1
-    # via stack-data
 attrs==25.4.0
     # via aiohttp
     # via jsonschema
@@ -63,31 +59,18 @@ click==8.1.8
     # via uvicorn
 cloudpickle==3.1.2
     # via agentex-sdk
-comm==0.2.3
-    # via ipykernel
 cryptography==46.0.6
     # via google-auth
     # via pyjwt
-datadog==0.52.1
-    # via agentex-sdk
 ddtrace==4.6.4
     # via agentex-sdk
-debugpy==1.8.20
-    # via ipykernel
-decorator==5.2.1
-    # via ipython
 distro==1.9.0
-    # via agentex-sdk
-    # via anthropic
+    # via agentex-sdk-client
     # via openai
     # via scale-gp
     # via scale-gp-beta
-docstring-parser==0.17.0
-    # via anthropic
 envier==0.6.1
     # via ddtrace
-executing==2.2.1
-    # via stack-data
 fastapi==0.136.1
     # via agentex-sdk
 fastuuid==0.14.0
@@ -114,8 +97,7 @@ hf-xet==1.4.2
 httpcore==1.0.9
     # via httpx
 httpx==0.28.1
-    # via agentex-sdk
-    # via anthropic
+    # via agentex-sdk-client
     # via genai-prices
     # via httpx-aiohttp
     # via huggingface-hub
@@ -128,7 +110,7 @@ httpx==0.28.1
     # via scale-gp
     # via scale-gp-beta
 httpx-aiohttp==0.1.12
-    # via agentex-sdk
+    # via agentex-sdk-client
 httpx-sse==0.4.3
     # via mcp
 huggingface-hub==1.8.0
@@ -141,21 +123,10 @@ idna==3.11
 importlib-metadata==8.5.0
     # via litellm
     # via opentelemetry-api
-iniconfig==2.3.0
-    # via pytest
-ipykernel==7.2.0
-    # via agentex-sdk
-ipython==9.12.0
-    # via ipykernel
-ipython-pygments-lexers==1.1.1
-    # via ipython
-jedi==0.19.2
-    # via ipython
 jinja2==3.1.6
     # via agentex-sdk
     # via litellm
 jiter==0.13.0
-    # via anthropic
     # via openai
 json-log-formatter==1.1.1
     # via agentex-sdk
@@ -171,11 +142,6 @@ jsonschema==4.23.0
     # via mcp
 jsonschema-specifications==2025.9.1
     # via jsonschema
-jupyter-client==8.8.0
-    # via ipykernel
-jupyter-core==5.9.1
-    # via ipykernel
-    # via jupyter-client
 kubernetes==28.1.0
     # via agentex-sdk
 langchain-core==1.2.23
@@ -192,9 +158,6 @@ markdown-it-py==4.0.0
     # via rich
 markupsafe==3.0.3
     # via jinja2
-matplotlib-inline==0.2.1
-    # via ipykernel
-    # via ipython
 mcp==1.26.0
     # via agentex-sdk
     # via claude-agent-sdk
@@ -204,8 +167,6 @@ mdurl==0.1.2
 multidict==6.7.0
     # via aiohttp
     # via yarl
-nest-asyncio==1.6.0
-    # via ipykernel
 nexus-rpc==1.4.0
     # via temporalio
 oauthlib==3.3.1
@@ -233,32 +194,15 @@ ormsgpack==1.12.2
     # via langgraph-checkpoint
 packaging==26.0
     # via huggingface-hub
-    # via ipykernel
     # via langchain-core
     # via langsmith
-    # via pytest
-parso==0.8.6
-    # via jedi
-pexpect==4.9.0
-    # via ipython
-platformdirs==4.9.4
-    # via jupyter-core
-pluggy==1.6.0
-    # via pytest
 prompt-toolkit==3.0.52
-    # via ipython
     # via questionary
 propcache==0.4.1
     # via aiohttp
     # via yarl
 protobuf==6.33.6
     # via temporalio
-psutil==7.2.2
-    # via ipykernel
-ptyprocess==0.7.0
-    # via pexpect
-pure-eval==0.2.3
-    # via stack-data
 pyasn1==0.6.3
     # via pyasn1-modules
 pyasn1-modules==0.4.2
@@ -266,8 +210,7 @@ pyasn1-modules==0.4.2
 pycparser==3.0
     # via cffi
 pydantic==2.12.5
-    # via agentex-sdk
-    # via anthropic
+    # via agentex-sdk-client
     # via fastapi
     # via genai-prices
     # via langchain-core
@@ -291,23 +234,13 @@ pydantic-graph==1.101.0
 pydantic-settings==2.13.1
     # via mcp
 pygments==2.20.0
-    # via ipython
-    # via ipython-pygments-lexers
-    # via pytest
     # via rich
 pyjwt==2.12.1
     # via mcp
-pytest==9.0.2
-    # via agentex-sdk
-    # via pytest-asyncio
-pytest-asyncio==1.3.0
-    # via agentex-sdk
 python-dateutil==2.9.0.post0
-    # via jupyter-client
     # via kubernetes
 python-dotenv==1.0.1
     # via litellm
-    # via mcp
     # via pydantic-settings
 python-multipart==0.0.22
     # via mcp
@@ -318,9 +251,6 @@ pyyaml==6.0.3
     # via huggingface-hub
     # via kubernetes
     # via langchain-core
-pyzmq==27.1.0
-    # via ipykernel
-    # via jupyter-client
 questionary==2.1.1
     # via agentex-sdk
 redis==7.4.0
@@ -331,7 +261,6 @@ referencing==0.37.0
 regex==2026.3.32
     # via tiktoken
 requests==2.33.1
-    # via datadog
     # via kubernetes
     # via langsmith
     # via openai-agents
@@ -350,7 +279,7 @@ rpds-py==0.30.0
     # via jsonschema
     # via referencing
 ruff==0.15.8
-    # via agentex-sdk
+    # via agentex-sdk-client
 scale-gp==0.1.0a61
     # via agentex-sdk
 scale-gp-beta==0.2.0
@@ -361,15 +290,12 @@ six==1.17.0
     # via kubernetes
     # via python-dateutil
 sniffio==1.3.1
-    # via agentex-sdk
-    # via anthropic
+    # via agentex-sdk-client
     # via openai
     # via scale-gp
     # via scale-gp-beta
 sse-starlette==3.0.3
     # via mcp
-stack-data==0.6.3
-    # via ipython
 starlette==1.0.0
     # via agentex-sdk
     # via fastapi
@@ -384,24 +310,13 @@ tiktoken==0.12.0
     # via litellm
 tokenizers==0.22.2
     # via litellm
-tornado==6.5.5
-    # via agentex-sdk
-    # via ipykernel
-    # via jupyter-client
 tqdm==4.67.3
     # via huggingface-hub
     # via openai
     # via python-on-whales
-traitlets==5.14.3
-    # via ipykernel
-    # via ipython
-    # via jupyter-client
-    # via jupyter-core
-    # via matplotlib-inline
 typer==0.16.1
     # via agentex-sdk
     # via huggingface-hub
-    # via mcp
     # via python-on-whales
 types-protobuf==6.32.1.20260221
     # via temporalio
@@ -410,9 +325,8 @@ types-requests==2.31.0.6
 types-urllib3==1.26.25.14
     # via types-requests
 typing-extensions==4.15.0
-    # via agentex-sdk
+    # via agentex-sdk-client
     # via aiosignal
-    # via anthropic
     # via anyio
     # via fastapi
     # via huggingface-hub
@@ -426,7 +340,6 @@ typing-extensions==4.15.0
     # via opentelemetry-semantic-conventions
     # via pydantic
     # via pydantic-core
-    # via pytest-asyncio
     # via python-on-whales
     # via referencing
     # via scale-gp
@@ -442,10 +355,6 @@ typing-inspection==0.4.2
     # via pydantic-ai-slim
     # via pydantic-graph
     # via pydantic-settings
-tzdata==2025.3
-    # via agentex-sdk
-tzlocal==5.3.1
-    # via agentex-sdk
 urllib3==1.26.20
     # via kubernetes
     # via requests
diff --git a/scripts/check-slim-deps b/scripts/check-slim-deps
new file mode 100755
index 000000000..8727c7fab
--- /dev/null
+++ b/scripts/check-slim-deps
@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+# Guardrail: the slim agentex-sdk-client must keep exactly its 6 bare-client deps
+# — Stainless re-emitting an un-trimmed dashboard dep-list would break the split.
+
+set -e
+
+cd "$(dirname "$0")/.."
+
+python3 - <<'PY'
+import re
+import sys
+import tomllib
+
+EXPECTED = {"httpx", "pydantic", "typing-extensions", "anyio", "distro", "sniffio"}
+
+
+def norm(name: str) -> str:
+    return re.sub(r"[-_.]+", "-", name.strip().lower())
+
+
+with open("pyproject.toml", "rb") as f:
+    deps = tomllib.load(f)["project"]["dependencies"]
+
+got = {norm(re.split(r"[<>=!~ \[;]", d, maxsplit=1)[0]) for d in deps}
+expected = {norm(n) for n in EXPECTED}
+
+if got != expected:
+    print("slim dependency drift in root pyproject.toml!", file=sys.stderr)
+    print(f"  expected ({len(expected)}): {sorted(expected)}", file=sys.stderr)
+    print(f"  got      ({len(got)}): {sorted(got)}", file=sys.stderr)
+    print(
+        "If Stainless re-added ADK deps, trim the dashboard dep-list "
+        "(ADK deps belong in adk/pyproject.toml).",
+        file=sys.stderr,
+    )
+    sys.exit(1)
+
+print(f"slim deps OK ({len(got)}): {sorted(got)}")
+PY
diff --git a/tests/test_function_tool.py b/tests/test_function_tool.py
index 91312e227..484ce8af2 100644
--- a/tests/test_function_tool.py
+++ b/tests/test_function_tool.py
@@ -6,7 +6,7 @@
 import pytest
 from pydantic import ValidationError
 
-from src.agentex.lib.core.temporal.activities.adk.providers.openai_activities import (  # type: ignore[import-untyped]
+from agentex.lib.core.temporal.activities.adk.providers.openai_activities import (
     FunctionTool,
 )