diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f21aad4..8f44a38 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -2,7 +2,7 @@ name: SDK validation
 on:
   pull_request:
   push:
-    branches: [development]
+    branches: [development, main]
 permissions:
   contents: read
 jobs:
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 9e5ee91..3173e84 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -1,20 +1,20 @@
 name: Publish reviewed SDK
 on:
+  push:
+    branches: [main]
   workflow_dispatch:
-    inputs:
-      tag:
-        description: Reviewed version tag reachable from development (for example v3.0.0)
-        required: true
-        type: string
 permissions:
   contents: read
 concurrency:
-  group: sdk-release-${{ inputs.tag }}
+  group: sdk-release-main
   cancel-in-progress: false
 jobs:
-  build:
-    if: github.ref == 'refs/heads/development'
+  prepare:
+    if: github.ref == 'refs/heads/main'
     runs-on: ubuntu-latest
+    outputs:
+      tag: ${{ steps.version.outputs.tag }}
+      publish: ${{ steps.version.outputs.publish }}
     steps:
       - uses: actions/checkout@fbc6f3992d24b796d5a048ff273f7fcc4a7b6c09 # v5
         with:
@@ -22,22 +22,44 @@ jobs:
       - uses: actions/setup-python@ece7cb06caefa5fff74198d8649806c4678c61a1 # v6
         with:
           python-version: '3.11'
-      - name: Validate and check out the reviewed release tag
+      - name: Select the version from the merged commit
+        id: version
         env:
-          RELEASE_TAG: ${{ inputs.tag }}
+          GH_TOKEN: ${{ github.token }}
         run: |
-          python -c "import os,re; assert re.fullmatch(r'v[0-9]+\.[0-9]+\.[0-9]+', os.environ['RELEASE_TAG'])"
-          git fetch origin "refs/tags/$RELEASE_TAG:refs/tags/$RELEASE_TAG"
-          git merge-base --is-ancestor "$RELEASE_TAG^{commit}" origin/development
-          git checkout --detach "$RELEASE_TAG"
-          python -c "import ast,os,pathlib; version=ast.literal_eval(ast.parse(pathlib.Path('extend/__version__.py').read_text()).body[0].value); assert 'v'+version == os.environ['RELEASE_TAG']"
+          gh release list --limit 1000 --json tagName > /tmp/releases.json
+          python - <<'PYTHON'
+          import ast, json, os, pathlib, re, subprocess
+          version = ast.literal_eval(ast.parse(pathlib.Path('extend/__version__.py').read_text()).body[0].value)
+          if not re.fullmatch(r'[0-9]+\.[0-9]+\.[0-9]+', version):
+              raise SystemExit('Expected a stable semantic version')
+          tag = 'v' + version
+          released = any(item['tagName'] == tag for item in json.loads(pathlib.Path('/tmp/releases.json').read_text()))
+          if not released:
+              existing = subprocess.run(['git', 'rev-parse', '--verify', f'refs/tags/{tag}^{{commit}}'], capture_output=True, text=True)
+              if existing.returncode == 0 and existing.stdout.strip() != os.environ['GITHUB_SHA']:
+                  raise SystemExit('Release tag already points to another commit; do not reuse versions')
+          with open(os.environ['GITHUB_OUTPUT'], 'a') as output:
+              output.write(f'tag={tag}\npublish={str(not released).lower()}\n')
+          PYTHON
+  build:
+    needs: prepare
+    if: needs.prepare.outputs.publish == 'true'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@fbc6f3992d24b796d5a048ff273f7fcc4a7b6c09 # v5
+        with:
+          fetch-depth: 0
+      - uses: actions/setup-python@ece7cb06caefa5fff74198d8649806c4678c61a1 # v6
+        with:
+          python-version: '3.11'
       - run: python -m pip install . pytest==9.2.0 pytest-asyncio==1.4.1 ruff==0.17.3 build==1.6.1
       - run: python -m ruff check extend tests tools
       - run: python -m pytest -q
       - run: python -m build
       - name: Validate the built wheel and its runtime graph
         env:
-          RELEASE_TAG: ${{ inputs.tag }}
+          RELEASE_TAG: ${{ needs.prepare.outputs.tag }}
         run: |
           python -m venv /tmp/release-wheel
           /tmp/release-wheel/bin/python -m pip install -c requirements.lock dist/*.whl pytest==9.2.0 pytest-asyncio==1.4.1
@@ -52,7 +74,7 @@ jobs:
           path: dist/*
           if-no-files-found: error
   publish:
-    needs: build
+    needs: [prepare, build]
     runs-on: ubuntu-latest
     environment: pypi
     permissions:
@@ -63,3 +85,18 @@ jobs:
           name: sdk-distributions
           path: dist
       - uses: pypa/gh-action-pypi-publish@7245906fb61fa33a13554f9d5fb856fe61758086 # release/v1
+        with:
+          skip-existing: true
+  release:
+    needs: [prepare, publish]
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - uses: actions/checkout@fbc6f3992d24b796d5a048ff273f7fcc4a7b6c09 # v5
+      - name: Create the version tag and GitHub release after publication
+        env:
+          GH_TOKEN: ${{ github.token }}
+          RELEASE_TAG: ${{ needs.prepare.outputs.tag }}
+        run: |
+          gh release create "$RELEASE_TAG" --target "$GITHUB_SHA" --title "$RELEASE_TAG" --notes-file CHANGELOG.md
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9918f0e..5577b68 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,15 +1,33 @@
 # Changelog
 
-## Unreleased
+All notable changes to this project are documented here using
+[Keep a Changelog](https://keepachangelog.com/en/1.0.0/) and
+[Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-- Make the default test suite offline, with full source and installed-wheel CI coverage.
-- Replace ambient live tests with explicit fixtures, opt-in writes, cleanup journals, and bounded automatch completion checks.
-- Add origin-constrained DELETE transport for resource cleanup; mutations are never retried.
+## [3.0.0]
 
-All notable changes to this project will be documented in this file.
+### Changed
+
+- **Breaking:** require Python 3.11 or newer and an explicit `stage` or `prod` environment.
+- **Breaking:** stop loading `.env` files automatically; applications own configuration loading.
+- **Breaking:** validate low-level endpoint paths and resource identifiers; pass query values through `params`.
+- Give clients independent authentication state and explicit asynchronous cleanup.
+- Align transaction pagination, filters, card dates, recurrence and expense-label null handling with API contracts.
+- Remove unused runtime dependencies; keep HTTPX as the only direct runtime dependency.
+
+### Added
+
+- Bounded retries for safe GET requests and structured, redacted API errors.
+- Resource wrappers for organizations, members, users, expense policies and individual labels, subject to endpoint availability and permissions.
+- Origin-constrained DELETE transport for resource cleanup; mutations are never retried.
+- Offline source and installed-wheel tests on Python 3.11 through 3.14, plus opt-in live validation with explicit fixtures and cleanup journals.
+- Migration, security and release documentation, dependency auditing and Trusted Publishing support.
+
+### Security
 
-The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
-and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+- Validate request destinations before attaching credentials and disable redirects.
+- Refresh authentication per request and prevent shared client credential reuse.
+- Remove sensitive request logging and implicit environment-file loading.
 
 ## [2.0.0] - 2025-10-26
 
diff --git a/MIGRATION.md b/MIGRATION.md
index af41368..d56ca8e 100644
--- a/MIGRATION.md
+++ b/MIGRATION.md
@@ -1,6 +1,6 @@
 # Migrating from 2.x to 3.x
 
-- Python 3.11 or newer is required. CI checks 3.11, 3.12 and 3.13.
+- Python 3.11 or newer is required. CI checks 3.11, 3.12, 3.13 and 3.14.
 - Select environment="stage" or environment="prod" when constructing a client.
   An explicitly set ENV=stage or ENV=prod is supported for migration. Missing,
   misspelled and legacy ENV=dev values fail at client construction. Import is safe.
@@ -25,11 +25,11 @@
 
 ## Releases
 
-Release publication is manual, from a versioned tag reachable from development.
-Run the release workflow on development with that tag after review and CI.
-The protected pypi environment and Trusted Publisher must already be configured.
-The workflow tests the source, builds a wheel, tests that wheel and publishes the
-same artifacts. Merging a PR does not publish a package.
+Merging a release PR into `main` automatically starts source validation, wheel
+validation and building. Publication waits for approval of the protected `pypi`
+environment, then uses Trusted Publishing and creates the version tag and GitHub
+release. Both the environment and Trusted Publisher must be configured first.
+See [RELEASING.md](RELEASING.md) for configuration and recovery instructions.
 
 ## Resource contracts
 
diff --git a/RELEASING.md b/RELEASING.md
new file mode 100644
index 0000000..fd674a3
--- /dev/null
+++ b/RELEASING.md
@@ -0,0 +1,38 @@
+# Publishing a release
+
+Releases promote reviewed changes to `main`. Merging a release PR automatically
+starts validation and building. Publication waits for approval of the `pypi`
+environment.
+
+## One-time publisher configuration
+
+1. Create the GitHub environment `pypi` and restrict deployment branches to `main`.
+   Configure the repository's required release reviewers before publishing.
+2. On PyPI, configure a Trusted Publisher for the existing `paywithextend` project:
+   owner `paywithextend`, repository `extend-python`, workflow `release.yml`,
+   environment `pypi`.
+3. Verify both configurations before releasing. The workflow uses GitHub OIDC;
+   the legacy `PYPI_API_TOKEN` secret is not used. Do not remove legacy credentials
+   until the replacement publisher has been verified.
+
+## Release procedure
+
+1. Update `extend/__version__.py`, the changelog and migration notes together.
+2. Open a release PR to `main`; require review and successful Python 3.11–3.14 CI.
+3. Merge the release PR. **Publish reviewed SDK** starts automatically on `main`,
+   reads the version from that exact commit, and skips versions with an existing
+   GitHub release. Never reuse a published version or move its tag.
+4. After source tests, installed-wheel tests and runtime advisory checks pass,
+   an authorized reviewer approves the `pypi` deployment in the Actions run.
+   GitHub publishes the validated artifacts through OIDC, then creates the version
+   tag and GitHub release at the merged commit using the changelog as release notes.
+5. Confirm both distributions exist on PyPI and a fresh installation reports the
+   expected version. For a failed run, use **Re-run failed jobs**. Publication skips
+   existing files so a partial upload or GitHub release failure can be recovered
+   without replacing published files. **Run workflow** on `main` remains available
+   for recovery; no tag input or manual tag creation is needed.
+6. Merge release-only metadata changes back into `development` when necessary.
+
+Publish SDK 3.0.0 before releasing packages that require `paywithextend==3.0.0`.
+A successful offline test run does not establish live endpoint availability or
+account permissions. See the availability notes in the README.