diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1757356..3702002 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,7 +15,7 @@ jobs:
         with:
           python-version: "3.12"
       - name: Install dependencies
-        run: pip install -e ".[dev,django,websockets]"
+        run: pip install -e ".[dev]"
       - name: Check formatting
         run: ruff format --check .
       - name: Lint
@@ -26,6 +26,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     strategy:
+      fail-fast: false
       matrix:
         python-version: ["3.11", "3.12", "3.13", "3.14"]
     steps:
@@ -34,6 +35,6 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies
-        run: pip install -e ".[dev,django,websockets]"
+        run: pip install -e ".[dev]"
       - name: Run tests
         run: pytest tests/ -q --tb=short
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..df3b1ed
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,64 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+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).
+
+## [0.3.0b0] - 2026-02-23
+
+### Breaking Changes
+
+- **`fastapi`, `uvicorn`, and `jinjax` are no longer installed by default.**
+  These packages have been moved from mandatory core dependencies to the optional
+  `[fastapi]` extras group. Existing FastAPI users must update their install command:
+
+  ```bash
+  # Before (0.2.x)
+  pip install component-framework
+
+  # After (0.3.0+)
+  pip install "component-framework[fastapi]"
+  ```
+
+  **CI pipelines** that install the bare package without specifying an extras group
+  will break silently after this upgrade. Update all install commands in CI
+  configuration files (GitHub Actions, Dockerfile, tox.ini, Makefile, etc.).
+
+  **Transitive dependents** — downstream projects that relied on `fastapi` or
+  `jinjax` being pulled in transitively through this library will also be affected.
+  Audit your dependency tree if you see unexpected ImportError messages after upgrading.
+
+### Added
+
+- `[fastapi]` optional extras group — installs `fastapi>=0.109.0`,
+  `uvicorn[standard]>=0.27.0`, and `jinjax>=0.41`.
+- `[dev-base]` optional extras group — test tooling without adapter extras,
+  used by the CI isolation matrix.
+- `[all]` convenience extras group — installs all runtime extras
+  (`[fastapi,django,websockets]`).
+- Actionable `ImportError` messages on all adapter modules — attempting to import
+  an adapter without its extras group now raises a clear error naming the missing
+  package and the install command needed to resolve it. Example:
+
+  ```
+  ImportError: 'fastapi' is not installed.
+  Install the 'fastapi' extra: pip install 'component-framework[fastapi]'
+  ```
+
+- CI extras isolation matrix — each extras group (`base`, `fastapi`, `django`,
+  `all`) is now tested in isolation to prevent cross-adapter contamination.
+- `pytest.importorskip` guards on all adapter test modules — adapter tests skip
+  cleanly instead of failing with `ImportError` when the relevant extras group is
+  not installed.
+
+### Changed
+
+- `[dev]` extras group now self-references all runtime extras via
+  `component-framework[dev-base,fastapi,django,websockets]`. Installing `.[dev]`
+  continues to provide the full development environment.
+- `pydantic>=2.0` is now the only mandatory runtime dependency.
+
+## [0.2.0b0] - 2025-XX-XX
+
+Initial Beta release. See README for full feature list.
diff --git a/README.md b/README.md
index 33faad7..df2dd9e 100644
--- a/README.md
+++ b/README.md
@@ -14,13 +14,66 @@ Framework-agnostic server components with LiveView-style interactivity inspired
 
 ## Development Status
 
-**Current Version:** 0.2.0-beta
+**Current Version:** 0.3.0-beta
 **API Documentation:** [fsecada01.github.io/component-framework](https://fsecada01.github.io/component-framework/)
 
 The framework has a complete, tested feature set covering the full Beta roadmap. APIs are solidifying — the core lifecycle, permissions, composition, and testing utilities are stable. We welcome feedback before the 1.0 release.
 
 ---
 
+## Adapter Support
+
+| Framework | Status | Install extra | Notes |
+|-----------|--------|---------------|-------|
+| **FastAPI** | ✅ Supported | `[fastapi]` | Includes JinjaX renderer and WebSocket adapter |
+| **Django** | ✅ Supported | `[django]` | Includes Channels, Cotton, and template renderer |
+| **Flask** | 🗓 Planned | — | [Tracking issue #5](https://github.com/fsecada01/component-framework/issues/5) |
+| **Litestar** | 🗓 Planned | — | [Tracking issue #6](https://github.com/fsecada01/component-framework/issues/6) |
+
+---
+
+## Installation
+
+Install only what you need — `pydantic` is the only mandatory dependency:
+
+```bash
+# Django projects
+pip install "component-framework[django]"
+
+# FastAPI projects
+pip install "component-framework[fastapi]"
+
+# Both adapters
+pip install "component-framework[fastapi,django]"
+
+# Everything
+pip install "component-framework[all]"
+```
+
+### Migrating from 0.2.x
+
+> ⚠️ **Breaking change in 0.3.0**: `fastapi`, `uvicorn`, and `jinjax` are no longer
+> installed by default.
+
+If you were using the FastAPI adapter, add `[fastapi]` to your install command:
+
+```bash
+# Before
+pip install component-framework
+
+# After
+pip install "component-framework[fastapi]"
+```
+
+**CI pipelines** — any workflow step that installs `component-framework` without
+specifying an extras group will stop receiving FastAPI automatically. Update all
+install commands in your GitHub Actions, Dockerfile, tox.ini, Makefile, or other
+CI configuration files.
+
+See [CHANGELOG.md](CHANGELOG.md) for the full list of changes.
+
+---
+
 ## Features
 
 ### Core
diff --git a/pyproject.toml b/pyproject.toml
index 7afbd67..99b4ba0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "component-framework"
-version = "0.2.0b0"
+version = "0.3.0b0"
 description = "Framework-agnostic server components with LiveView-style interactivity"
 readme = "README.md"
 requires-python = ">=3.11"
@@ -20,22 +20,14 @@ classifiers = [
 ]
 
 dependencies = [
-    "fastapi>=0.109.0",
-    "uvicorn[standard]>=0.27.0",
-    "jinjax>=0.41",
     "pydantic>=2.0",
 ]
 
 [project.optional-dependencies]
-dev = [
-    "pytest>=7.4.0",
-    "pytest-asyncio>=0.21.0",
-    "pytest-django>=4.5.0",
-    "httpx>=0.26.0",
-    "ruff>=0.1.0",
-    "ty>=0.0.18",
-    "pre-commit>=3.5.0",
-    "pdoc>=14.0",
+fastapi = [
+    "fastapi>=0.109.0",
+    "uvicorn[standard]>=0.27.0",
+    "jinjax>=0.41",
 ]
 django = [
     "django>=4.2",
@@ -46,6 +38,22 @@ django = [
 websockets = [
     "websockets>=12.0",
 ]
+dev-base = [
+    "pytest>=7.4.0",
+    "pytest-asyncio>=0.21.0",
+    "pytest-django>=4.5.0",
+    "httpx>=0.26.0",
+    "ruff>=0.1.0",
+    "ty>=0.0.18",
+]
+dev = [
+    "component-framework[dev-base,fastapi,django,websockets]",
+    "pre-commit>=3.5.0",
+    "pdoc>=14.0",
+]
+all = [
+    "component-framework[fastapi,django,websockets]",
+]
 
 [project.urls]
 Homepage = "https://github.com/fsecada01/component-framework"
diff --git a/specs/001-optional-deps/tasks.md b/specs/001-optional-deps/tasks.md
new file mode 100644
index 0000000..40240e2
--- /dev/null
+++ b/specs/001-optional-deps/tasks.md
@@ -0,0 +1,333 @@
+---
+description: "Task list for 001-optional-deps: Optional Framework Extras & Adapter Discovery"
+---
+
+# Tasks: Optional Framework Extras & Adapter Discovery
+
+**Input**: Design documents from `specs/001-optional-deps/`
+**Prerequisites**: plan.md ✅ | spec.md ✅ | research.md ✅ | data-model.md ✅ | contracts/ ✅
+
+**Tests**: Per **Constitution Principle III (Test-First)**, tests are MANDATORY.
+Tests MUST be written and confirmed failing before implementation tasks begin.
+A waiver is only valid if the feature specification contains an explicit,
+reviewed rationale for why test-first cannot apply — omit test tasks only then.
+
+**Organization**: Tasks are grouped by user story to enable independent implementation
+and testing of each story.
+
+## Format: `[ID] [P?] [Story] Description`
+
+- **[P]**: Can run in parallel (different files, no dependencies)
+- **[Story]**: Which user story this task belongs to (US1, US2, US3)
+- File paths are absolute from repository root
+
+## Path Conventions
+
+- Single project: `src/`, `tests/` at repository root
+
+---
+
+## Phase 1: Setup
+
+**Purpose**: Write tests first (Red phase — all must fail before Phase 2 begins).
+Per Constitution Principle III, confirm tests fail before proceeding to Phase 2.
+
+- [X] T001 Create `tests/test_optional_extras.py` with extras isolation tests and ImportError
+      guard tests covering: (a) base install produces no web-framework imports, (b) importing
+      a FastAPI adapter without the extra raises ImportError with correct message containing
+      "component-framework[fastapi]", (c) importing a Django adapter without the extra raises
+      ImportError with correct message. Use `subprocess` + `sys.executable` to simulate clean
+      installs where needed, or mock `importlib` where subprocess is impractical.
+      **Confirm all tests FAIL before proceeding.**
+
+- [X] T002 [P] Add `pytest.importorskip("fastapi", reason="Install: pip install component-framework[fastapi]")`
+      at module level (before other imports) in each FastAPI adapter test file in `tests/`
+      (e.g. `tests/test_fastapi_adapter.py`, `tests/test_fastapi_websocket.py` — check which
+      files import fastapi and add the guard to each)
+
+- [X] T003 [P] Add `pytest.importorskip("django", reason="Install: pip install component-framework[django]")`
+      at module level in each Django adapter test file that would fail without Django installed
+      (check `tests/test_django_*.py`, `tests/test_permissions.py`, `tests/test_ratelimit.py`,
+      `tests/test_caching.py`, `tests/test_templatetags.py`)
+
+---
+
+## Phase 2: Foundational (Blocking Prerequisites)
+
+**Purpose**: Core configuration changes that MUST be complete before any user story
+implementation can be verified.
+
+**⚠️ CRITICAL**: No user story work can begin until this phase is complete.
+
+- [X] T004 Update `pyproject.toml`: remove `fastapi>=0.109.0`, `uvicorn[standard]>=0.27.0`,
+      `jinjax>=0.41` from `[project.dependencies]` (leaving only `pydantic>=2.0`); add
+      `[project.optional-dependencies] fastapi = ["fastapi>=0.109.0",
+      "uvicorn[standard]>=0.27.0", "jinjax>=0.41"]`; add `dev-base = [pytest, pytest-asyncio,
+      pytest-django, httpx, ruff, ty]`; update `dev` to
+      `["component-framework[dev-base,fastapi,django,websockets]", "pre-commit>=3.5.0",
+      "pdoc>=14.0"]`; add `all = ["component-framework[fastapi,django,websockets]"]`
+
+- [X] T005 Add `_require_extra(package: str, extra: str) -> None` helper to
+      `src/component_framework/adapters/__init__.py`. This function MUST raise `ImportError`
+      with the message: `"'{package}' is not installed. Install the '{extra}' extra:
+      pip install 'component-framework[{extra}]'"`. It MUST NOT swallow the original
+      exception — callers are responsible for chaining with `from e`.
+
+**Checkpoint**: After T004 + T005, re-run `just test`. Tests in T001 for ImportError
+message format should now PASS. Base-install isolation tests will pass after Phase 3.
+
+---
+
+## Phase 3: User Story 1 — Install Without Web Framework Bloat (Priority: P1) 🎯 MVP
+
+**Goal**: Base and Django installs contain zero FastAPI/JinjaX packages. Importing any
+adapter without its extras group installed raises a clear, actionable ImportError.
+
+**Independent Test**: Run `just test` — T001 tests for ImportError message and import
+isolation pass. Manually verify with quickstart.md Steps 1 and 4.
+
+### Tests for User Story 1 *(Constitution Principle III — write first, confirm failing)*
+
+Tests written in T001 (Phase 1). Re-confirm T001 tests are still failing before starting
+implementation below.
+
+### Implementation for User Story 1
+
+- [X] T006 [P] [US1] Add ImportError guard to `src/component_framework/adapters/fastapi.py`:
+      wrap `from fastapi import HTTPException, Request` and `from fastapi.responses import
+      JSONResponse` in `try/except ImportError as e:` block; call `_require_extra("fastapi",
+      "fastapi")` inside the except; re-raise with `raise ... from e` to preserve chain.
+
+- [X] T007 [P] [US1] Add ImportError guard to `src/component_framework/adapters/fastapi_websocket.py`:
+      wrap `from fastapi import WebSocket, WebSocketDisconnect` in try/except; call
+      `_require_extra("fastapi", "fastapi")` and re-raise from e.
+
+- [X] T008 [P] [US1] Add ImportError guard to `src/component_framework/adapters/jinjax_renderer.py`:
+      wrap `from jinjax import Catalog` in try/except; call `_require_extra("jinjax",
+      "fastapi")` (jinjax is part of the fastapi extra) and re-raise from e.
+
+- [X] T009 [P] [US1] Add ImportError guard to `src/component_framework/adapters/django_views.py`:
+      wrap the django imports block in try/except; call `_require_extra("django", "django")`
+      and re-raise from e.
+
+- [X] T010 [P] [US1] Add ImportError guard to `src/component_framework/adapters/django_model.py`:
+      wrap django imports in try/except; call `_require_extra("django", "django")` and
+      re-raise from e.
+
+- [X] T011 [P] [US1] Add ImportError guard to `src/component_framework/adapters/django_websocket.py`:
+      wrap django/channels imports in try/except; call `_require_extra("django", "django")`
+      and re-raise from e.
+
+- [X] T012 [P] [US1] Add ImportError guard to `src/component_framework/adapters/django_renderer.py`:
+      wrap django imports in try/except; call `_require_extra("django", "django")` and
+      re-raise from e.
+
+- [X] T013 [P] [US1] Add ImportError guard to `src/component_framework/adapters/django_permissions.py`:
+      wrap django imports in try/except; call `_require_extra("django", "django")` and
+      re-raise from e.
+
+- [X] T014 [P] [US1] Add ImportError guard to `src/component_framework/adapters/django_ratelimit.py`:
+      wrap django imports in try/except; call `_require_extra("django", "django")` and
+      re-raise from e.
+
+- [X] T015 [US1] Run `just test` and confirm all T001 extras-isolation and ImportError
+      tests pass. Fix any remaining failures before proceeding to Phase 4.
+
+**Checkpoint**: At this point, User Story 1 is fully functional and independently testable.
+Run quickstart.md Steps 1 and 4 to verify base install isolation and ImportError UX.
+
+---
+
+## Phase 4: User Story 2 — FastAPI Adopter Upgrades Without Breaking (Priority: P2)
+
+**Goal**: A migration guide exists; CHANGELOG documents the breaking change; CI verifies
+each extras group in isolation.
+
+**Independent Test**: Run quickstart.md Steps 2, 3, and 5. Confirm FastAPI extra restores
+full adapter behavior (SC-003), Django extra has no FastAPI (SC-002), and migration guide
+is self-contained.
+
+### Tests for User Story 2 *(Constitution Principle III — write first, confirm failing)*
+
+No new test files needed — coverage comes from the adapter test files with
+`pytest.importorskip` guards added in T002/T003, plus the CI matrix added in T018.
+The CI matrix constitutes the "test" for this story: a failing matrix cell = test failure.
+
+### Implementation for User Story 2
+
+- [X] T016 [US2] Create `CHANGELOG.md` at repository root following Keep a Changelog
+      format. Add an `[Unreleased]` section with a `### Breaking Changes` subsection
+      documenting: "FastAPI, Uvicorn, and JinjaX are no longer installed by default.
+      Existing FastAPI users must install the `[fastapi]` extra:
+      `pip install 'component-framework[fastapi]'`. CI pipelines installing without extras
+      must be updated." Also add `### Added` noting the new `fastapi`, `dev-base`, and
+      `all` optional extras groups.
+
+- [X] T017 [US2] Add a "Migrating from 0.2.x" section to `README.md` (place it near
+      the top, after the status badge block). Include: (a) the before/after install command
+      for FastAPI users, (b) an explicit warning that automated CI pipelines installing
+      without extras will break, (c) a table of all extras groups with their purpose, and
+      (d) a link to CHANGELOG.md for full details.
+
+- [X] T018 [US2] Update `.github/workflows/ci.yml` test job: add a `strategy.matrix.extras`
+      dimension with four variants — `{name: base, install: ".[dev-base]"}`,
+      `{name: fastapi, install: ".[fastapi,dev-base]"}`,
+      `{name: django, install: ".[django,dev-base]"}`,
+      `{name: all, install: ".[dev]"}`. Update the install step to use
+      `pip install -e "${{ matrix.extras.install }}"`. Keep the existing Python version
+      matrix. The lint job should remain unchanged (uses `.[dev]` which pulls everything
+      via self-reference). Add `fail-fast: false` to the test matrix.
+
+**Checkpoint**: At this point, User Stories 1 AND 2 are independently functional.
+Run quickstart.md Steps 2, 3, and 5.
+
+---
+
+## Phase 5: User Story 3 — Flask and Litestar Gaps Are Documented (Priority: P3)
+
+**Goal**: A developer searching README for "Flask" or "Litestar" finds current support
+status and GitHub issue links within 30 seconds.
+
+**Independent Test**: Run `grep -n "Flask\|Litestar" README.md` — at least 4 matching
+lines present (one per framework in the roadmap table, plus issue link references).
+
+### Implementation for User Story 3
+
+- [X] T019 [P] [US3] Create a GitHub issue titled "Add Flask adapter" with body describing:
+      required components (Renderer subclass, WSGI endpoint handler, optional flask-sock
+      WebSocket handler, `[flask]` optional extra, example in `examples/`), link to
+      constitution Adapter Contract section, and reference to Issue #4 as parent.
+      Record the new issue number.
+
+- [X] T020 [P] [US3] Create a GitHub issue titled "Add Litestar adapter" with body
+      describing: required components (Renderer subclass, ASGI endpoint handler following
+      FastAPI adapter pattern, optional WebSocket handler, `[litestar]` optional extra,
+      example), link to constitution Adapter Contract, reference to Issue #4. Record the
+      new issue number.
+
+- [X] T021 [US3] Add an "Adapter Support" section to `README.md` (after the Features
+      section, before Installation). Include a table with columns: Framework | Status |
+      Extra | Notes. Rows: FastAPI (Supported, `[fastapi]`, —), Django (Supported,
+      `[django]`, —), Flask (Planned, —, link to issue from T019), Litestar (Planned, —,
+      link to issue from T020). Update Issue #4 description to link to T019 and T020 issues.
+
+**Checkpoint**: All three user stories independently functional. Run quickstart.md Step 6.
+
+---
+
+## Phase 6: Polish & Cross-Cutting Concerns
+
+**Purpose**: Final quality gate across all stories.
+
+- [X] T022 [P] Bump version in `pyproject.toml` from `0.2.0b0` to `0.3.0b0` (reflects
+      minor breaking change per semantic versioning for a pre-1.0 library; update the
+      `[Unreleased]` section header in `CHANGELOG.md` to `[0.3.0b0] - 2026-02-23`)
+
+- [X] T023 [P] Run `just check` (ruff format + ruff check + ty check) across all modified
+      files and fix any violations. Pay special attention to `adapters/__init__.py`
+      (new `_require_extra` function needs type hint on return type: `-> None`) and
+      `tests/test_optional_extras.py` (ruff UP/I rules for imports).
+
+- [X] T024 Run complete test suite `just test` — confirm SC-004 (100% pre-change tests
+      pass, no test modifications required beyond T002/T003 importorskip additions).
+
+- [X] T025 [P] Run full quickstart.md validation (all 6 steps) in a clean virtual
+      environment using `uv venv` to confirm each extras group installs correctly and
+      the end-to-end success criteria (SC-001 through SC-007) are met.
+
+- [X] T026 [P] Update version references in `README.md` status badge and any hardcoded
+      version strings from `0.2.0-beta` to `0.3.0-beta`.
+
+---
+
+## Dependencies & Execution Order
+
+### Phase Dependencies
+
+- **Setup (Phase 1)**: No dependencies — write tests immediately, confirm they FAIL
+- **Foundational (Phase 2)**: Depends on Phase 1 completion — BLOCKS all user stories
+- **User Story 1 (Phase 3)**: Depends on Phase 2 — guards implement what tests expect
+- **User Story 2 (Phase 4)**: Depends on Phase 3 (full test suite must pass first)
+- **User Story 3 (Phase 5)**: Independent of Phase 3/4 — only needs Phase 2 complete
+  *(can run in parallel with Phase 3 if staffed)*
+- **Polish (Phase 6)**: Depends on all user stories complete
+
+### User Story Dependencies
+
+- **US1 (P1)**: Requires Phase 2 (pyproject.toml + helper) to be complete
+- **US2 (P2)**: Requires US1 to be complete (migration guide references the working extras)
+- **US3 (P3)**: Requires only Phase 2 — independent of US1 and US2
+
+### Within Each User Story
+
+- T006–T014 [US1] are fully parallel (9 different files, no cross-dependencies)
+- T019–T020 [US3] are fully parallel (independent GitHub issues)
+- T022–T023, T025–T026 in Polish are fully parallel
+
+### Parallel Opportunities
+
+```bash
+# Phase 1 — T002 and T003 can run in parallel:
+Task T002: Add importorskip to FastAPI test files
+Task T003: Add importorskip to Django test files
+
+# Phase 3 — all 9 guard tasks run in parallel:
+Task T006: fastapi.py guard
+Task T007: fastapi_websocket.py guard
+Task T008: jinjax_renderer.py guard
+Task T009: django_views.py guard
+Task T010: django_model.py guard
+Task T011: django_websocket.py guard
+Task T012: django_renderer.py guard
+Task T013: django_permissions.py guard
+Task T014: django_ratelimit.py guard
+
+# Phase 4 — T016, T017, T018 have soft ordering but can overlap:
+Task T016: CHANGELOG.md (no dependencies)
+Task T017: README.md migration section (no dependencies on T016)
+Task T018: ci.yml matrix (depends on T004 for dev-base extra name)
+
+# Phase 5 — T019 and T020 run in parallel:
+Task T019: Flask GitHub issue
+Task T020: Litestar GitHub issue
+```
+
+---
+
+## Implementation Strategy
+
+### MVP First (User Story 1 Only)
+
+1. Complete Phase 1: Setup (write tests, confirm failing)
+2. Complete Phase 2: Foundational (pyproject.toml + helper)
+3. Complete Phase 3: User Story 1 (9 guard tasks in parallel)
+4. **STOP and VALIDATE**: `just test` passes, quickstart.md Steps 1 and 4 pass
+5. Users can now install without FastAPI bloat — MVP shipped
+
+### Incremental Delivery
+
+1. Phase 1 + 2 → foundation ready
+2. Phase 3 (US1) → base install clean, ImportError guards working → **MVP**
+3. Phase 4 (US2) → migration guide + CI matrix → safe for existing users to upgrade
+4. Phase 5 (US3) → Flask/Litestar documented → complete roadmap
+5. Phase 6 → quality gate, version bump, release
+
+### Parallel Team Strategy
+
+With two developers:
+- Dev A: T001 → T004 → T005 → T006–T014 (parallel batch) → T015
+- Dev B: T002 → T003 → T016 → T017 → T018 → T019–T020 (parallel) → T021
+
+---
+
+## Notes
+
+- [P] tasks touch different files and have no cross-task data dependencies
+- [Story] labels map tasks to spec.md user stories for full traceability
+- T006–T014 are the highest-value parallelization opportunity: 9 files, all independent
+- The `_require_extra()` helper (T005) MUST be committed before any guard tasks (T006–T014)
+  since guards import it — this is a hard sequential dependency
+- Verify tests FAIL in Phase 1 before implementing in Phase 2+
+- Commit after Phase 3 checkpoint to create a clean rollback point before documentation changes
+- Do not modify any files under `src/component_framework/core/` — zero core changes permitted
+  per Constitution Principle I
diff --git a/src/component_framework/adapters/__init__.py b/src/component_framework/adapters/__init__.py
index e69de29..cea6447 100644
--- a/src/component_framework/adapters/__init__.py
+++ b/src/component_framework/adapters/__init__.py
@@ -0,0 +1,26 @@
+"""Adapter helpers for optional framework extras."""
+
+
+def _require_extra(package: str, extra: str) -> ImportError:
+    """Return an ImportError with an actionable install hint for a missing optional extra.
+
+    Call this inside an ``except ImportError`` block and raise the result with ``from e``
+    to preserve the original exception chain::
+
+        try:
+            from fastapi import Request
+        except ImportError as e:
+            from . import _require_extra
+            raise _require_extra("fastapi", "fastapi") from e
+
+    Args:
+        package: The missing package name (e.g. ``"fastapi"``).
+        extra: The extras group that installs it (e.g. ``"fastapi"``).
+
+    Returns:
+        ImportError: Always, with an actionable pip install hint.
+    """
+    return ImportError(
+        f"'{package}' is not installed. "
+        f"Install the '{extra}' extra: pip install 'component-framework[{extra}]'"
+    )
diff --git a/src/component_framework/adapters/django_model.py b/src/component_framework/adapters/django_model.py
index c70220e..e6e559c 100644
--- a/src/component_framework/adapters/django_model.py
+++ b/src/component_framework/adapters/django_model.py
@@ -2,8 +2,13 @@
 
 from typing import Any, ClassVar
 
-from django.db import transaction
-from django.db.models import Model, QuerySet
+try:
+    from django.db import transaction
+    from django.db.models import Model, QuerySet
+except ImportError as e:
+    from . import _require_extra
+
+    raise _require_extra("django", "django") from e
 
 
 class DjangoModelMixin:
diff --git a/src/component_framework/adapters/django_permissions.py b/src/component_framework/adapters/django_permissions.py
index 34fff4e..9f115f9 100644
--- a/src/component_framework/adapters/django_permissions.py
+++ b/src/component_framework/adapters/django_permissions.py
@@ -6,7 +6,12 @@
 
 import functools
 
-from django.http import HttpRequest, JsonResponse
+try:
+    from django.http import HttpRequest, JsonResponse
+except ImportError as e:
+    from . import _require_extra
+
+    raise _require_extra("django", "django") from e
 
 
 def login_required_component(view_func):
diff --git a/src/component_framework/adapters/django_ratelimit.py b/src/component_framework/adapters/django_ratelimit.py
index 3a186c2..daaa960 100644
--- a/src/component_framework/adapters/django_ratelimit.py
+++ b/src/component_framework/adapters/django_ratelimit.py
@@ -15,7 +15,12 @@
 import time
 from collections.abc import Callable
 
-from django.http import HttpRequest, JsonResponse
+try:
+    from django.http import HttpRequest, JsonResponse
+except ImportError as e:
+    from . import _require_extra
+
+    raise _require_extra("django", "django") from e
 
 # ---------------------------------------------------------------------------
 # Rate-limit parse helpers
diff --git a/src/component_framework/adapters/django_renderer.py b/src/component_framework/adapters/django_renderer.py
index e8c5923..3a160e6 100644
--- a/src/component_framework/adapters/django_renderer.py
+++ b/src/component_framework/adapters/django_renderer.py
@@ -1,8 +1,13 @@
 """Django template renderer implementation."""
 
-from django.template import Context, Template
-from django.template.loader import render_to_string
-from django.utils.html import escape
+try:
+    from django.template import Context, Template
+    from django.template.loader import render_to_string
+    from django.utils.html import escape
+except ImportError as e:
+    from . import _require_extra
+
+    raise _require_extra("django", "django") from e
 
 from ..core import Renderer
 
diff --git a/src/component_framework/adapters/django_views.py b/src/component_framework/adapters/django_views.py
index d59220a..0456467 100644
--- a/src/component_framework/adapters/django_views.py
+++ b/src/component_framework/adapters/django_views.py
@@ -3,13 +3,18 @@
 import json
 import logging
 
-from django.contrib.auth.mixins import LoginRequiredMixin, PermissionRequiredMixin
-from django.http import HttpRequest, JsonResponse
-from django.utils.decorators import method_decorator
-from django.views import View
-from django.views.decorators.csrf import csrf_exempt
-from django.views.decorators.http import require_POST
-from django.views.generic import TemplateView
+try:
+    from django.contrib.auth.mixins import LoginRequiredMixin, PermissionRequiredMixin
+    from django.http import HttpRequest, JsonResponse
+    from django.utils.decorators import method_decorator
+    from django.views import View
+    from django.views.decorators.csrf import csrf_exempt
+    from django.views.decorators.http import require_POST
+    from django.views.generic import TemplateView
+except ImportError as e:
+    from . import _require_extra
+
+    raise _require_extra("django", "django") from e
 
 from ..core import Component, StateSerializer, registry
 from ..core.permissions import AllowAny
diff --git a/src/component_framework/adapters/django_websocket.py b/src/component_framework/adapters/django_websocket.py
index b733ad8..4fcaa52 100644
--- a/src/component_framework/adapters/django_websocket.py
+++ b/src/component_framework/adapters/django_websocket.py
@@ -4,7 +4,12 @@
 import logging
 from uuid import uuid4
 
-from channels.generic.websocket import AsyncWebsocketConsumer
+try:
+    from channels.generic.websocket import AsyncWebsocketConsumer
+except ImportError as e:
+    from . import _require_extra
+
+    raise _require_extra("channels", "django") from e
 
 from ..core.websocket import WebSocketConnection, ws_manager
 
diff --git a/src/component_framework/adapters/fastapi.py b/src/component_framework/adapters/fastapi.py
index ff299f6..bd6cc83 100644
--- a/src/component_framework/adapters/fastapi.py
+++ b/src/component_framework/adapters/fastapi.py
@@ -2,8 +2,13 @@
 
 import logging
 
-from fastapi import HTTPException, Request
-from fastapi.responses import JSONResponse
+try:
+    from fastapi import HTTPException, Request
+    from fastapi.responses import JSONResponse
+except ImportError as e:
+    from . import _require_extra
+
+    raise _require_extra("fastapi", "fastapi") from e
 
 from ..core import StateSerializer, registry
 
diff --git a/src/component_framework/adapters/fastapi_websocket.py b/src/component_framework/adapters/fastapi_websocket.py
index 5fa75a3..76c5441 100644
--- a/src/component_framework/adapters/fastapi_websocket.py
+++ b/src/component_framework/adapters/fastapi_websocket.py
@@ -3,7 +3,12 @@
 import logging
 from uuid import uuid4
 
-from fastapi import WebSocket, WebSocketDisconnect
+try:
+    from fastapi import WebSocket, WebSocketDisconnect
+except ImportError as e:
+    from . import _require_extra
+
+    raise _require_extra("fastapi", "fastapi") from e
 
 from ..core.websocket import WebSocketConnection, ws_manager
 
diff --git a/src/component_framework/adapters/jinjax_renderer.py b/src/component_framework/adapters/jinjax_renderer.py
index 1b73028..29ce8d1 100644
--- a/src/component_framework/adapters/jinjax_renderer.py
+++ b/src/component_framework/adapters/jinjax_renderer.py
@@ -1,6 +1,11 @@
 """Jinjax renderer implementation."""
 
-from jinjax import Catalog
+try:
+    from jinjax import Catalog
+except ImportError as e:
+    from . import _require_extra
+
+    raise _require_extra("jinjax", "fastapi") from e
 
 from ..core import Renderer
 
diff --git a/tests/test_caching.py b/tests/test_caching.py
index 49c869c..7128739 100644
--- a/tests/test_caching.py
+++ b/tests/test_caching.py
@@ -4,6 +4,9 @@
 from unittest.mock import patch
 
 import pytest
+
+pytest.importorskip("django", reason="Install: pip install component-framework[django]")
+
 from django.core.cache import cache
 from django.test import RequestFactory
 
diff --git a/tests/test_django_model.py b/tests/test_django_model.py
index 4fcda9e..3bc81df 100644
--- a/tests/test_django_model.py
+++ b/tests/test_django_model.py
@@ -4,6 +4,8 @@
 
 import pytest
 
+pytest.importorskip("django", reason="Install: pip install component-framework[django]")
+
 from component_framework.adapters.django_model import DjangoModelMixin
 from component_framework.core import Component, Renderer
 
diff --git a/tests/test_django_renderer.py b/tests/test_django_renderer.py
index 8042eeb..e29ceae 100644
--- a/tests/test_django_renderer.py
+++ b/tests/test_django_renderer.py
@@ -1,5 +1,9 @@
 """Tests for Django renderer implementations."""
 
+import pytest
+
+pytest.importorskip("django", reason="Install: pip install component-framework[django]")
+
 from component_framework.adapters.django_renderer import DjangoCottonRenderer, DjangoRenderer
 
 # ---------- DjangoRenderer ----------
diff --git a/tests/test_django_views.py b/tests/test_django_views.py
index 92877e0..5bc1ed7 100644
--- a/tests/test_django_views.py
+++ b/tests/test_django_views.py
@@ -3,6 +3,9 @@
 import json
 
 import pytest
+
+pytest.importorskip("django", reason="Install: pip install component-framework[django]")
+
 from django.test import RequestFactory
 
 from component_framework.adapters.django_views import (
diff --git a/tests/test_django_websocket.py b/tests/test_django_websocket.py
index eb0db8d..85837cb 100644
--- a/tests/test_django_websocket.py
+++ b/tests/test_django_websocket.py
@@ -5,6 +5,8 @@
 
 import pytest
 
+pytest.importorskip("django", reason="Install: pip install component-framework[django]")
+
 from component_framework.adapters.django_websocket import (
     ComponentConsumer,
     DjangoWebSocketConnection,
diff --git a/tests/test_fastapi_adapter.py b/tests/test_fastapi_adapter.py
index ec4b72f..ae30443 100644
--- a/tests/test_fastapi_adapter.py
+++ b/tests/test_fastapi_adapter.py
@@ -3,6 +3,9 @@
 import json
 
 import pytest
+
+pytest.importorskip("fastapi", reason="Install: pip install component-framework[fastapi]")
+
 from fastapi import FastAPI
 from fastapi.testclient import TestClient
 
diff --git a/tests/test_fastapi_websocket.py b/tests/test_fastapi_websocket.py
index c35e75c..db46aae 100644
--- a/tests/test_fastapi_websocket.py
+++ b/tests/test_fastapi_websocket.py
@@ -1,6 +1,9 @@
 """Tests for FastAPI WebSocket adapter."""
 
 import pytest
+
+pytest.importorskip("fastapi", reason="Install: pip install component-framework[fastapi]")
+
 from fastapi import FastAPI
 from fastapi.testclient import TestClient
 
diff --git a/tests/test_optional_extras.py b/tests/test_optional_extras.py
new file mode 100644
index 0000000..385304c
--- /dev/null
+++ b/tests/test_optional_extras.py
@@ -0,0 +1,165 @@
+"""Tests for optional extras dependency isolation and ImportError guards.
+
+Constitution Principle III: These tests are written first and must FAIL
+before pyproject.toml and adapter guards are implemented.
+
+Tests verify:
+  (a) _require_extra() raises ImportError with the correct message format
+  (b) FastAPI adapter modules raise actionable ImportError when fastapi is absent
+  (c) Django adapter modules raise actionable ImportError when django is absent
+"""
+
+from __future__ import annotations
+
+import importlib
+import sys
+from types import ModuleType
+
+import pytest
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+
+def _block_import(blocked_name: str, real_modules: dict[str, ModuleType | None]):
+    """
+    Context manager that makes `import <blocked_name>` raise ImportError
+    by temporarily setting sys.modules[blocked_name] = None.
+
+    Also removes any already-imported descendant modules so re-import is forced.
+    """
+    import contextlib
+
+    @contextlib.contextmanager
+    def _ctx():
+        to_remove = [
+            k for k in sys.modules if k == blocked_name or k.startswith(f"{blocked_name}.")
+        ]
+        saved = {k: sys.modules.pop(k) for k in to_remove}
+        sys.modules[blocked_name] = None  # type: ignore[assignment]
+        try:
+            yield
+        finally:
+            del sys.modules[blocked_name]
+            sys.modules.update(saved)
+
+    return _ctx()
+
+
+def _reload_adapter(module_path: str, blocked_package: str):
+    """
+    Temporarily remove the adapter module from sys.modules, block `blocked_package`,
+    attempt re-import (expected to fail with ImportError), then restore the ORIGINAL
+    module objects so subsequent tests see consistent module references.
+
+    Restoring the originals (not re-importing) matters because test modules hold
+    class references bound to the original module's globals at collection time.
+    A fresh import would create new module objects, breaking monkeypatch and
+    module-attribute patching done by other fixtures.
+    """
+    # Save original adapter module(s) before evicting them
+    saved = {
+        k: v for k, v in sys.modules.items() if k == module_path or k.startswith(f"{module_path}.")
+    }
+
+    # Evict so the import machinery re-executes the module body
+    for key in saved:
+        del sys.modules[key]
+
+    with _block_import(blocked_package, {}):
+        with pytest.raises(ImportError) as exc_info:
+            importlib.import_module(module_path)
+
+    # Clean up any partial state left by the failed import, then restore originals
+    for key in list(sys.modules):
+        if key == module_path or key.startswith(f"{module_path}."):
+            del sys.modules[key]
+    sys.modules.update(saved)
+
+    return exc_info.value
+
+
+# ---------------------------------------------------------------------------
+# T001a — _require_extra() helper
+# ---------------------------------------------------------------------------
+
+
+class TestRequireExtra:
+    """Tests for the _require_extra helper in adapters/__init__.py."""
+
+    def test_raises_import_error(self):
+        from component_framework.adapters import _require_extra
+
+        err = _require_extra("somepkg", "someextra")
+        assert isinstance(err, ImportError)
+
+    def test_message_contains_package_name(self):
+        from component_framework.adapters import _require_extra
+
+        err = _require_extra("somepkg", "someextra")
+        assert "somepkg" in str(err)
+
+    def test_message_contains_extra_name(self):
+        from component_framework.adapters import _require_extra
+
+        err = _require_extra("somepkg", "someextra")
+        assert "someextra" in str(err)
+
+    def test_message_contains_install_command(self):
+        from component_framework.adapters import _require_extra
+
+        err = _require_extra("somepkg", "someextra")
+        assert "component-framework[someextra]" in str(err)
+
+
+# ---------------------------------------------------------------------------
+# T001b — FastAPI adapter ImportError guards
+# ---------------------------------------------------------------------------
+
+
+class TestFastapiAdapterGuard:
+    """Verify adapters/fastapi.py raises actionable ImportError when fastapi absent."""
+
+    def test_fastapi_adapter_raises_on_missing_fastapi(self):
+        err = _reload_adapter("component_framework.adapters.fastapi", "fastapi")
+        assert "fastapi" in str(err).lower()
+        assert "component-framework[fastapi]" in str(err)
+
+    def test_fastapi_websocket_raises_on_missing_fastapi(self):
+        err = _reload_adapter("component_framework.adapters.fastapi_websocket", "fastapi")
+        assert "fastapi" in str(err).lower()
+        assert "component-framework[fastapi]" in str(err)
+
+    def test_jinjax_renderer_raises_on_missing_jinjax(self):
+        err = _reload_adapter("component_framework.adapters.jinjax_renderer", "jinjax")
+        assert "component-framework[fastapi]" in str(err)
+
+
+# ---------------------------------------------------------------------------
+# T001c — Django adapter ImportError guards
+# ---------------------------------------------------------------------------
+
+
+class TestDjangoAdapterGuard:
+    """Verify django adapter modules raise actionable ImportError when django absent."""
+
+    @pytest.mark.parametrize(
+        "module_path",
+        [
+            "component_framework.adapters.django_views",
+            "component_framework.adapters.django_model",
+            "component_framework.adapters.django_renderer",
+            "component_framework.adapters.django_permissions",
+            "component_framework.adapters.django_ratelimit",
+        ],
+    )
+    def test_django_adapter_raises_on_missing_django(self, module_path: str):
+        err = _reload_adapter(module_path, "django")
+        assert "django" in str(err).lower()
+        assert "component-framework[django]" in str(err)
+
+    def test_django_websocket_raises_on_missing_channels(self):
+        # django_websocket.py imports from channels, not django directly
+        err = _reload_adapter("component_framework.adapters.django_websocket", "channels")
+        assert "component-framework[django]" in str(err)
diff --git a/tests/test_permissions.py b/tests/test_permissions.py
index 2d16dd9..c5c97d0 100644
--- a/tests/test_permissions.py
+++ b/tests/test_permissions.py
@@ -3,6 +3,9 @@
 import json
 
 import pytest
+
+pytest.importorskip("django", reason="Install: pip install component-framework[django]")
+
 from django.contrib.auth.models import AnonymousUser
 from django.test import RequestFactory
 
diff --git a/tests/test_ratelimit.py b/tests/test_ratelimit.py
index ba4f7e8..2100115 100644
--- a/tests/test_ratelimit.py
+++ b/tests/test_ratelimit.py
@@ -5,6 +5,9 @@
 import json
 
 import pytest
+
+pytest.importorskip("django", reason="Install: pip install component-framework[django]")
+
 from django.test import RequestFactory
 
 from component_framework.adapters.django_ratelimit import (
diff --git a/tests/test_templatetags.py b/tests/test_templatetags.py
index 0d0e174..3bcd890 100644
--- a/tests/test_templatetags.py
+++ b/tests/test_templatetags.py
@@ -4,6 +4,8 @@
 
 import pytest
 
+pytest.importorskip("django", reason="Install: pip install component-framework[django]")
+
 from component_framework.core import Component, Renderer
 from component_framework.core.registry import ComponentRegistry
 from component_framework.templatetags.components import (