chore(version): Bump version and update changelog for 1.25.0

Merge https://github.com/google/adk-python/pull/4455

**Please ensure you have read the [contribution guide](https://github.com/google/adk-python/blob/main/CONTRIBUTING.md) before creating a pull request.**

### Link to Issue or Description of Change

**1. Link to an existing issue (if applicable):**

- Closes: #_issue_number_
- Related: #_issue_number_

**2. Or, if no issue exists, describe the change:**

_If applicable, please follow the issue templates to provide as much detail as
possible._

**Problem:**
_A clear and concise description of what the problem is._

**Solution:**
_A clear and concise description of what you want to happen and why you choose
this solution._

### Testing Plan

_Please describe the tests that you ran to verify your changes. This is required
for all PRs that are not small documentation or typo fixes._

**Unit Tests:**

- [ ] I have added or updated unit tests for my change.
- [ ] All unit tests pass locally.

_Please include a summary of passed `pytest` results._

**Manual End-to-End (E2E) Tests:**

_Please provide instructions on how to manually test your changes, including any
necessary setup or configuration. Please provide logs or screenshots to help
reviewers better understand the fix._

### Checklist

- [ ] I have read the [CONTRIBUTING.md](https://github.com/google/adk-python/blob/main/CONTRIBUTING.md) document.
- [ ] I have performed a self-review of my own code.
- [ ] I have commented my code, particularly in hard-to-understand areas.
- [ ] I have added tests that prove my fix is effective or that my feature works.
- [ ] New and existing unit tests pass locally with my changes.
- [ ] I have manually tested my changes end-to-end.
- [ ] Any dependent changes have been merged and published in downstream modules.

### Additional context

_Add any other context or screenshots about the feature request here._

COPYBARA_INTEGRATE_REVIEW=https://github.com/google/adk-python/pull/4455 from google:release/candidate f660ec82ff4140ef1deea95182e6e0cc62100f89
PiperOrigin-RevId: 868877872

.github/.release-please-manifest.json

@@ -0,0 +1,3 @@
+{
+  ".": "1.24.1"
+}

.github/release-please-config.json

@@ -0,0 +1,24 @@
+{
+  "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json",
+  "packages": {
+    ".": {
+      "release-type": "python",
+      "package-name": "google-adk",
+      "include-component-in-tag": false,
+      "skip-github-release": true,
+      "changelog-path": "CHANGELOG.md",
+      "changelog-sections": [
+        {"type": "feat", "section": "Features"},
+        {"type": "fix", "section": "Bug Fixes"},
+        {"type": "perf", "section": "Performance Improvements"},
+        {"type": "refactor", "section": "Code Refactoring"},
+        {"type": "docs", "section": "Documentation"},
+        {"type": "test", "section": "Tests", "hidden": true},
+        {"type": "build", "section": "Build System", "hidden": true},
+        {"type": "ci", "section": "CI/CD", "hidden": true},
+        {"type": "style", "section": "Styles", "hidden": true},
+        {"type": "chore", "section": "Miscellaneous Chores", "hidden": true}
+      ]
+    }
+  }
+}

.github/release-please.yml

@@ -1,5 +0,0 @@
-releaseType: python
-handleGHRelease: true
-bumpMinorPreMajor: false
-extraFiles:
-  - src/google/adk/version.py

.github/release-trigger.yml

@@ -1 +0,0 @@
-enabled: true

.github/workflows/isort.yml

@@ -33,7 +33,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v6
         with:
-          python-version: '3.x'
+          python-version: '3.11'
 
       - name: Install isort
         run: |

.github/workflows/pyink.yml

@@ -33,7 +33,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v6
         with:
-          python-version: '3.x'
+          python-version: '3.11'
 
       - name: Install pyink
         run: |

.github/workflows/python-unit-tests.yml

@@ -25,7 +25,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.10", "3.11", "3.12", "3.13"]
+        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
 
     steps:
     - name: Checkout code

.github/workflows/release-cherry-pick.yml

@@ -0,0 +1,46 @@
+# Cherry-picks a commit from main to the release/candidate branch.
+# Use this to include bug fixes in an in-progress release.
+name: "Release: Cherry-pick"
+
+on:
+  workflow_dispatch:
+    inputs:
+      commit_sha:
+        description: 'Commit SHA to cherry-pick'
+        required: true
+        type: string
+
+permissions:
+  contents: write
+  actions: write
+
+jobs:
+  cherry-pick:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: release/candidate
+          fetch-depth: 0
+
+      - name: Configure git
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+
+      - name: Cherry-pick commit
+        run: |
+          echo "Cherry-picking ${{ inputs.commit_sha }} to release/candidate"
+          git cherry-pick ${{ inputs.commit_sha }}
+
+      - name: Push changes
+        run: |
+          git push origin release/candidate
+          echo "Successfully cherry-picked commit to release/candidate"
+
+      - name: Trigger Release Please
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          gh workflow run release-please.yml --repo ${{ github.repository }}
+          echo "Triggered Release Please workflow"

.github/workflows/release-cut.yml

@@ -0,0 +1,46 @@
+# Starts the release process by creating a release/candidate branch.
+# Triggers release-please to generate a changelog PR.
+name: "Release: Cut"
+
+on:
+  workflow_dispatch:
+    inputs:
+      commit_sha:
+        description: 'Commit SHA to cut from (leave empty for latest main)'
+        required: false
+        type: string
+
+permissions:
+  contents: write
+  actions: write
+
+jobs:
+  cut-release:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ inputs.commit_sha || 'main' }}
+
+      - name: Check for existing release/candidate branch
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          if git ls-remote --exit-code --heads origin release/candidate &>/dev/null; then
+            echo "Error: release/candidate branch already exists"
+            echo "Please finalize or delete the existing release candidate before starting a new one"
+            exit 1
+          fi
+
+      - name: Create and push release/candidate branch
+        run: |
+          git checkout -b release/candidate
+          git push origin release/candidate
+          echo "Created branch: release/candidate"
+
+      - name: Trigger Release Please
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          gh workflow run release-please.yml --repo ${{ github.repository }}
+          echo "Triggered Release Please workflow"

.github/workflows/release-finalize.yml

@@ -0,0 +1,66 @@
+# Triggers when release-please PR is merged to release/candidate.
+# Creates the final release/v{version} branch and deletes the candidate branch.
+name: "Release: Finalize"
+
+on:
+  pull_request:
+    types: [closed]
+    branches:
+      - release/candidate
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  finalize:
+    if: github.event.pull_request.merged == true
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check for release-please PR
+        id: check
+        env:
+          LABELS: ${{ toJson(github.event.pull_request.labels.*.name) }}
+        run: |
+          if echo "$LABELS" | grep -q "autorelease: pending"; then
+            echo "is_release_pr=true" >> $GITHUB_OUTPUT
+          else
+            echo "Not a release-please PR, skipping"
+            echo "is_release_pr=false" >> $GITHUB_OUTPUT
+          fi
+
+      - uses: actions/checkout@v4
+        if: steps.check.outputs.is_release_pr == 'true'
+        with:
+          ref: release/candidate
+
+      - name: Extract version from manifest
+        if: steps.check.outputs.is_release_pr == 'true'
+        id: version
+        run: |
+          VERSION=$(jq -r '.["."]' .github/.release-please-manifest.json)
+          echo "version=$VERSION" >> $GITHUB_OUTPUT
+          echo "Extracted version: $VERSION"
+
+      - name: Create release branch
+        if: steps.check.outputs.is_release_pr == 'true'
+        run: |
+          git checkout -b "release/v${{ steps.version.outputs.version }}"
+          git push origin "release/v${{ steps.version.outputs.version }}"
+          echo "Created branch: release/v${{ steps.version.outputs.version }}"
+
+      - name: Delete release/candidate branch
+        if: steps.check.outputs.is_release_pr == 'true'
+        run: |
+          git push origin --delete release/candidate
+          echo "Deleted branch: release/candidate"
+
+      - name: Update PR label to tagged
+        if: steps.check.outputs.is_release_pr == 'true'
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          gh pr edit ${{ github.event.pull_request.number }} \
+            --remove-label "autorelease: pending" \
+            --add-label "autorelease: tagged"
+          echo "Updated PR label to autorelease: tagged"

.github/workflows/release-please.yml

@@ -0,0 +1,30 @@
+# Runs release-please to create/update a PR with version bump and changelog.
+# Triggered by pushes to release/candidate or manually.
+name: "Release: Please"
+
+on:
+  push:
+    branches:
+      - release/candidate
+  workflow_dispatch:
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  release-please:
+    # Skip if this is a release-please PR merge (handled by Release: Finalize)
+    if: "!startsWith(github.event.head_commit.message, 'chore(release')"
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: release/candidate
+
+      - uses: googleapis/release-please-action@v4
+        with:
+          token: ${{ secrets.RELEASE_PAT }}
+          config-file: .github/release-please-config.json
+          manifest-file: .github/.release-please-manifest.json
+          target-branch: release/candidate

.github/workflows/release-publish.yml

@@ -0,0 +1,59 @@
+# Builds and publishes the package to PyPI from a release branch.
+# Creates a merge-back PR to sync release changes to main.
+name: "Release: Publish to PyPi"
+
+on:
+  workflow_dispatch:
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Validate branch
+        run: |
+          if [[ ! "${{ github.ref_name }}" =~ ^release/v[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
+            echo "Error: Must run from a release/v* branch (e.g., release/v0.3.0)"
+            exit 1
+          fi
+
+      - name: Extract version
+        id: version
+        run: |
+          VERSION="${{ github.ref_name }}"
+          VERSION="${VERSION#release/v}"
+          echo "version=$VERSION" >> $GITHUB_OUTPUT
+          echo "Publishing version: $VERSION"
+
+      - uses: actions/checkout@v4
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v4
+        with:
+          version: "latest"
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Build package
+        run: uv build
+
+      - name: Publish to PyPI
+        env:
+          UV_PUBLISH_TOKEN: ${{ secrets.PYPI_TOKEN }}
+        run: uv publish
+
+      - name: Create merge-back PR
+        env:
+          GH_TOKEN: ${{ secrets.RELEASE_PAT }}
+        run: |
+          gh pr create \
+            --base main \
+            --head "${{ github.ref_name }}" \
+            --title "chore: merge release v${{ steps.version.outputs.version }} to main" \
+            --body "Syncs version bump and CHANGELOG from release v${{ steps.version.outputs.version }} to main."

CHANGELOG.md

@@ -1,5 +1,49 @@
 # Changelog
 
+## [1.25.0](https://github.com/google/adk-python/compare/v1.24.1...v1.25.0) (2026-02-11)
+
+### Features
+
+* **[Core]**
+  * Add a demo for the simple prompt optimizer for the optimization interface ([0abf4cd](https://github.com/google/adk-python/commit/0abf4cd2c7103a071506c9398455a3bd66fe5da5))
+  * Add `--auto_create_session` flag to `adk api_server` CLI ([40c15d0](https://github.com/google/adk-python/commit/40c15d059599472b40f48272a464eb3cb7345fc6))
+  * Add `add_events_to_memory` facade for event-delta ([59e8897](https://github.com/google/adk-python/commit/59e88972ae4f10274444593db0607f40cfcc597e))
+  * Add post-invocation token-threshold compaction with event retention ([a88e864](https://github.com/google/adk-python/commit/a88e8647558a9b9d0bfdf38d2d8de058e3ba0596))
+  * Add report generation to `adk conformance test` command ([43c437e](https://github.com/google/adk-python/commit/43c437e38b9109b68a81de886d1901e4d8f87a01))
+
+* **[Models]**
+  * Add base_url option to Gemini LLM class ([781f605](https://github.com/google/adk-python/commit/781f605a1e5de6d77b69d7e7b9835ec6fc8de4bf))
+
+* **[Tools]**
+  * Enhance google credentials config to support externally passed access token ([3cf43e3](https://github.com/google/adk-python/commit/3cf43e3842d9987499ea70d6f63d6e1c4d4a07db))
+  * Update agent simulator by improving prompts and add environment data ([7af1858](https://github.com/google/adk-python/commit/7af1858f46b66fa4471c5ba7943385f2d23d08d3))
+  * Add a load MCP resource tool ([e25227d](https://github.com/google/adk-python/commit/e25227da5e91a8c1192af709f8e8bb2a471ded92))
+  * Add SkillToolset to adk ([8d02792](https://github.com/google/adk-python/commit/8d0279251ce4fad6f0c84bd7777eb5a74f7ba07a))
+
+* **[Web]**
+  * Add `/health` and `/version` endpoints to ADK web server ([25ec2c6](https://github.com/google/adk-python/commit/25ec2c6b614cf8d185ff6dbdac5697a210be68da))
+
+### Bug Fixes
+
+* Use async iteration for VertexAiSessionService.list_sessions pagination ([758d337](https://github.com/google/adk-python/commit/758d337c76d877e3174c35f06551cc9beb1def06))
+* Fix event loop closed bug in McpSessionManager ([4aa4751](https://github.com/google/adk-python/commit/4aa475145f196fb35fe97290dd9f928548bc737f))
+* Preserve thought_signature in function call conversions for interactions API integration ([2010569](https://github.com/google/adk-python/commit/20105690100d9c2f69c061ac08be5e94c50dc39c))
+* Propagate grounding and citation metadata in streaming responses ([e6da417](https://github.com/google/adk-python/commit/e6da4172924ecc36ffc2535199c450a2a51c7bcc))
+* Add endpoints to get/list artifact version metadata ([e0b9712](https://github.com/google/adk-python/commit/e0b9712a492bf84ac17679095b333642a79b8ee6))
+* Support escaped curly braces in instruction templates ([7c7d25a](https://github.com/google/adk-python/commit/7c7d25a4a6e4389e23037e70b8efdcd5341f44ea))
+* Strip timezone for PostgreSQL timestamps in DatabaseSessionService ([19b6076](https://github.com/google/adk-python/commit/19b607684f15ce2b6ffd60382211ba5600705743))
+* Prompt token may be None in streaming mode ([32ee07d](https://github.com/google/adk-python/commit/32ee07df01f10dbee0e98ca9d412440a7fe9163d))
+* Pass invocation_id from `/run` endpoint to `Runner.run_async` ([d2dba27](https://github.com/google/adk-python/commit/d2dba27134f833e5d929fdf363ada9364cc852f9))
+* Conditionally preserve function call IDs in LLM requests ([663cb75](https://github.com/google/adk-python/commit/663cb75b3288d8d0649412e1009329502b21cbbc))
+* Migrate VertexAiMemoryBankService to use the async Vertex AI client ([64a44c2](https://github.com/google/adk-python/commit/64a44c28974de77cf8934f9c3d1bc03691b90e7b))
+* Handle list values in Gemini schema sanitization ([fd8a9e3](https://github.com/google/adk-python/commit/fd8a9e3962cca4f422beb7316cbe732edf726d51))
+* Used logger to log instead of print in MCP ([6bc70a6](https://github.com/google/adk-python/commit/6bc70a6bab79b679a4b18ad146b3450fb9014475))
+
+### Improvements
+
+* Replace check of instance for LlmAgent with hasAttribute check ([7110336](https://github.com/google/adk-python/commit/7110336788662abb8c9bbbb0a53a50cc09130d5e))
+* Log exception details before re-raising in MCP session execution ([de79bf1](https://github.com/google/adk-python/commit/de79bf12b564a4eefc7e6a2568dbe0f08bb6efeb))
+
 ## [1.24.1](https://github.com/google/adk-python/compare/v1.24.0...v1.24.1) (2026-02-06)
 
 ### Bug Fixes

contributing/dev/utils/build_llms_txt.py

@@ -1,4 +1,18 @@
 #!/usr/bin/env python3
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 """
 build_llms_txt.py – produce llms.txt and llms-full.txt
                    – skips ```java``` blocks
@@ -6,6 +20,7 @@ build_llms_txt.py – produce llms.txt and llms-full.txt
                    – includes Python API reference from HTML files
                    – includes adk-python repository README
 """
+
 from __future__ import annotations
 
 import argparse

contributing/samples/cache_analysis/run_cache_experiments.py

@@ -344,7 +344,8 @@ async def analyze_cache_performance_from_sessions(
       print(
           "     Cache Utilization:"
           f" {cached_analysis['cache_utilization_ratio_percent']:.1f}%"
-          f" ({cached_analysis['requests_with_cache_hits']}/{cached_analysis['total_requests']} requests)"
+          f" ({cached_analysis['requests_with_cache_hits']}/{cached_analysis['total_requests']}"
+          " requests)"
       )
       print(
           "     Avg Cached Tokens/Request:"
@@ -383,7 +384,8 @@ async def analyze_cache_performance_from_sessions(
       print(
           "     Cache Utilization:"
           f" {uncached_analysis['cache_utilization_ratio_percent']:.1f}%"
-          f" ({uncached_analysis['requests_with_cache_hits']}/{uncached_analysis['total_requests']} requests)"
+          f" ({uncached_analysis['requests_with_cache_hits']}/{uncached_analysis['total_requests']}"
+          " requests)"
       )
       print(
           "     Avg Cached Tokens/Request:"

contributing/samples/gepa/tau_bench_agent.py

@@ -23,6 +23,7 @@ cd tau-bench/
 pip install -e . --quiet
 ```
 """
+
 from __future__ import annotations
 
 from typing import Any

contributing/samples/human_in_loop/main.py

@@ -113,8 +113,8 @@ async def main():
       updated_tool_output_data = {
           "status": "approved",
           "ticketId": ticket_id,
-          "approver_feedback": "Approved by manager at " + str(
-              asyncio.get_event_loop().time()
+          "approver_feedback": (
+              "Approved by manager at " + str(asyncio.get_event_loop().time())
           ),
       }
 

contributing/samples/langchain_structured_tool_agent/agent.py

@@ -15,6 +15,7 @@
 """
 This agent aims to test the Langchain tool with Langchain's StructuredTool
 """
+
 from google.adk.agents.llm_agent import Agent
 from google.adk.tools.langchain_tool import LangchainTool
 from langchain_core.tools import tool

contributing/samples/postgres_session_service/README.md

@@ -0,0 +1,198 @@
+# Using PostgreSQL with DatabaseSessionService
+
+This sample demonstrates how to configure `DatabaseSessionService` to use PostgreSQL for persisting sessions, events, and state.
+
+## Overview
+
+ADK's `DatabaseSessionService` supports multiple database backends through SQLAlchemy. This guide shows how to:
+
+- Set up PostgreSQL as the session storage backend
+- Configure async connections with `asyncpg`
+- Understand the auto-generated schema
+- Run the sample agent with persistent sessions
+
+## Prerequisites
+
+- **PostgreSQL Database**: A running PostgreSQL instance (local or cloud)
+- **asyncpg**: Async PostgreSQL driver for Python
+
+## Installation
+
+Install the required Python packages:
+
+```bash
+pip install google-adk asyncpg greenlet
+```
+
+## Database Schema
+
+`DatabaseSessionService` automatically creates the following tables on first use:
+
+### sessions
+
+| Column      | Type         | Description                    |
+| ----------- | ------------ | ------------------------------ |
+| app_name    | VARCHAR(128) | Application identifier (PK)    |
+| user_id     | VARCHAR(128) | User identifier (PK)           |
+| id          | VARCHAR(128) | Session UUID (PK)              |
+| state       | JSONB        | Session state as JSON          |
+| create_time | TIMESTAMP    | Creation timestamp             |
+| update_time | TIMESTAMP    | Last update timestamp          |
+
+### events
+
+| Column             | Type         | Description                    |
+| ------------------ | ------------ | ------------------------------ |
+| id                 | VARCHAR(256) | Event UUID (PK)                |
+| app_name           | VARCHAR(128) | Application identifier (PK)    |
+| user_id            | VARCHAR(128) | User identifier (PK)           |
+| session_id         | VARCHAR(128) | Session reference (PK, FK)     |
+| invocation_id      | VARCHAR(256) | Invocation identifier          |
+| timestamp          | TIMESTAMP    | Event timestamp                |
+| event_data         | JSONB        | Event content as JSON          |
+
+### app_states
+
+| Column      | Type         | Description                    |
+| ----------- | ------------ | ------------------------------ |
+| app_name    | VARCHAR(128) | Application identifier (PK)    |
+| state       | JSONB        | Application-level state        |
+| update_time | TIMESTAMP    | Last update timestamp          |
+
+### user_states
+
+| Column      | Type         | Description                    |
+| ----------- | ------------ | ------------------------------ |
+| app_name    | VARCHAR(128) | Application identifier (PK)    |
+| user_id     | VARCHAR(128) | User identifier (PK)           |
+| state       | JSONB        | User-level state               |
+| update_time | TIMESTAMP    | Last update timestamp          |
+
+### adk_internal_metadata
+
+| Column      | Type         | Description                    |
+| ----------- | ------------ | ------------------------------ |
+| key         | VARCHAR(128) | Metadata key                   |
+| value       | VARCHAR(256) | Metadata value                 |
+
+
+## Configuration
+
+### Connection URL Format
+
+```python
+postgresql+asyncpg://username:password@host:port/database
+```
+
+### Basic Usage
+
+```python
+from google.adk.sessions.database_session_service import DatabaseSessionService
+from google.adk.runners import Runner
+
+# Initialize with PostgreSQL URL
+session_service = DatabaseSessionService(
+    "postgresql+asyncpg://postgres:postgres@localhost:5432/adk_sessions"
+)
+
+# Use with Runner
+runner = Runner(
+    app_name="my_app",
+    agent=my_agent,
+    session_service=session_service,
+)
+```
+
+### Advanced Configuration
+
+Pass additional SQLAlchemy engine options:
+
+```python
+session_service = DatabaseSessionService(
+    "postgresql+asyncpg://postgres:postgres@localhost:5432/adk_sessions",
+    pool_size=10,
+    max_overflow=20,
+    pool_timeout=30,
+    pool_recycle=1800,
+)
+```
+
+## Running the Sample
+
+### 1. Start PostgreSQL
+
+Using Docker:
+
+```bash
+docker compose up -d
+```
+
+Or use an existing PostgreSQL instance.
+
+### 2. Configure Connection
+
+Create a `.env` file:
+
+```bash
+POSTGRES_URL=postgresql+asyncpg://postgres:postgres@localhost:5432/adk_sessions
+GOOGLE_CLOUD_PROJECT=<your-gcp-project-id>
+GOOGLE_CLOUD_LOCATION=us-central1
+GOOGLE_GENAI_USE_VERTEXAI=true
+```
+
+Or run export command.
+
+```bash
+export POSTGRES_URL=postgresql+asyncpg://postgres:postgres@localhost:5432/adk_sessions
+export GOOGLE_CLOUD_PROJECT=$(gcloud config get-value project)
+export GOOGLE_CLOUD_LOCATION=us-central1
+export GOOGLE_GENAI_USE_VERTEXAI=true
+```
+
+### 3. Run the Agent
+
+```bash
+python main.py
+```
+
+Or use the ADK:
+
+```bash
+adk run .
+```
+
+## Session Persistence
+
+Sessions and events are persisted across application restarts:
+
+```python
+# First run - creates a new session
+session = await session_service.create_session(
+    app_name="my_app",
+    user_id="user1",
+    session_id="persistent-session-123",
+)
+
+# Later run - retrieves the existing session
+session = await session_service.get_session(
+    app_name="my_app",
+    user_id="user1",
+    session_id="persistent-session-123",
+)
+```
+
+## State Management
+
+PostgreSQL's JSONB type provides efficient storage for state data:
+
+- **Session state**: Stored in `sessions.state`
+- **User state**: Stored in `user_states.state`
+- **App state**: Stored in `app_states.state`
+
+## Production Considerations
+
+1. **Connection Pooling**: Use `pool_size` and `max_overflow` for high-traffic applications
+2. **SSL/TLS**: Always use encrypted connections in production
+3. **Backups**: Implement regular backup strategies for session data
+4. **Indexing**: The default schema includes primary key indexes; add additional indexes based on query patterns
+5. **Monitoring**: Monitor connection pool usage and query performance

contributing/samples/postgres_session_service/__init__.py

@@ -0,0 +1,16 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+from . import agent