diff --git a/.agents/exploration/interleavethinker-fastvideo-integration.md b/.agents/exploration/interleavethinker-fastvideo-integration.md
index cd0a2c72d..58c9eb169 100644
--- a/.agents/exploration/interleavethinker-fastvideo-integration.md
+++ b/.agents/exploration/interleavethinker-fastvideo-integration.md
@@ -3074,3 +3074,39 @@ Next recommended integration step:
   - validation matrix covering service, run CLI, prompt-set eval, trace eval,
     SFT, critic GRPO, planner GRPO, and real-checkpoint smokes;
   - PR split recommendation and unresolved risks.
+
+## Stage 13 Execution: Review Package
+
+Status: completed locally, pending commit/push.
+
+Goal:
+
+- Add a stable review entrypoint outside the long exploration log.
+- Summarize public surfaces, validation evidence, PR split, and remaining risks
+  for reviewers.
+
+Implemented changes:
+
+- Added `docs/design/interleave_thinker.md`.
+  - Public inference/orchestration surfaces.
+  - Public training/model/reward surfaces.
+  - Architecture boundaries.
+  - Representative Modal validation matrix.
+  - Recommended PR stack.
+  - Remaining risks and review checklist.
+- Added the page to the MkDocs Design nav in `mkdocs.yml`.
+
+Validation completed:
+
+- Local `git diff --check` passed.
+- Local `pre-commit run --files docs/design/interleave_thinker.md mkdocs.yml`
+  passed:
+  - codespell;
+  - PyMarkdown;
+  - filename check;
+  - suggestion hook.
+  - yapf, ruff, mypy, and actionlint had no files to check.
+- Local `python scripts/check_docs_links.py` failed on pre-existing generated
+  examples links under `docs/examples/`, `docs/getting_started/`, `docs/inference/`,
+  and `docs/training/`. No failures referenced the new
+  `docs/design/interleave_thinker.md` page.
diff --git a/docs/design/interleave_thinker.md b/docs/design/interleave_thinker.md
new file mode 100644
index 000000000..457dcd9bd
--- /dev/null
+++ b/docs/design/interleave_thinker.md
@@ -0,0 +1,173 @@
+# InterleaveThinker Integration Design
+
+This page summarizes the InterleaveThinker integration branch for reviewers. It
+captures the public FastVideo surfaces, validation evidence, recommended PR
+split, and remaining risks. The detailed execution log remains in
+`.agents/exploration/interleavethinker-fastvideo-integration.md`.
+
+## Scope
+
+The branch adds FastVideo-native support for InterleaveThinker-style workflows:
+
+- generator compatibility through a FastVideo-backed `/edit` API;
+- planner -> generator -> critic inference orchestration;
+- prompt-set and trace-level evaluation tools;
+- Qwen3-VL planner and critic model wrappers;
+- planner and critic SFT configs;
+- planner and critic GRPO configs with optional reference-policy KL;
+- Gemini and Nano Banana API wrappers for reward and image-generation backends.
+
+It does not vendor InterleaveThinker, EasyR1, Verl, LLaMA-Factory, or training
+framework internals from those projects. FastVideo owns the public orchestration,
+model-wrapper, reward, and training-method boundaries.
+
+## Public Surfaces
+
+### Inference And Orchestration
+
+| Surface | Purpose |
+|---------|---------|
+| `fastvideo.entrypoints.interleave` | Public package exports for orchestration, providers, prompt-set evaluation, trace serialization, and trace evaluation. |
+| `fastvideo interleave-serve` | Starts an InterleaveThinker-compatible FastVideo image edit service with `/edit`, `/generate`, and `/v1/interleave/edit` routes. |
+| `fastvideo interleave-run` | Runs one planner -> generator -> critic trace from a nested YAML config. |
+| `fastvideo interleave-eval` | Runs the same workflow over a JSONL/JSON/text prompt set and writes per-sample traces plus `summary.json`. |
+| `scripts/interleave_thinker/evaluate_traces.py` | Evaluates saved trace outputs and optionally writes an HTML report with final-image thumbnails. |
+
+Examples live under `examples/interleave/`:
+
+- `flux2_klein_interleave_serve.yaml`;
+- `interleave_run.yaml`;
+- `eval_prompts.jsonl`;
+- `interleave_single_prompt.py`.
+
+### Training
+
+| Surface | Purpose |
+|---------|---------|
+| `fastvideo.train.models.interleave_thinker.Qwen3VLActorBase` | Shared Transformers Qwen3-VL runtime for planner and critic actors. |
+| `InterleaveThinkerPlannerModel` | FastVideo `ModelBase` wrapper for `InterleaveThinker/InterleaveThinker-Planner-8B`. |
+| `InterleaveThinkerCriticModel` | FastVideo `ModelBase` wrapper for `InterleaveThinker/Critic-SFT-8B` and `InterleaveThinker/InterleaveThinker-Critic-8B`. |
+| `InterleaveThinkerSFTMethod` | Response-token supervised fine-tuning method for planner and critic actors. |
+| `InterleaveThinkerRLMethod` | Managed GRPO-style loop for planner and critic actors. |
+| `fastvideo.train.methods.rl.common.grpo` | Shared GRPO math helpers. |
+| `fastvideo.train.methods.rl.rewards.interleave_thinker` | Format, critic, and planner reward utilities. |
+| `fastvideo.train.methods.rl.rewards.interleave_api` | Gemini and Nano Banana API-backed reward/image wrappers. |
+
+Training examples live under:
+
+- `examples/train/configs/interleave_thinker/planner_sft_lora.yaml`;
+- `examples/train/configs/interleave_thinker/critic_sft_lora.yaml`;
+- `examples/train/configs/interleave_thinker/planner_smoke.yaml`;
+- `examples/train/configs/rl/interleave_thinker/critic_grpo.yaml`;
+- `examples/train/configs/rl/interleave_thinker/planner_grpo.yaml`.
+
+## Architecture Boundaries
+
+The integration is intentionally split into independent layers:
+
+| Layer | Owner | Notes |
+|-------|-------|-------|
+| Planner and critic actors | `fastvideo/train/models/interleave_thinker/` | Wrap Transformers Qwen3-VL checkpoints. They are training actors, not diffusion pipeline components. |
+| RL/SFT algorithms | `fastvideo/train/methods/` | Own loss, reward aggregation, advantage computation, KL, and optimizer cadence. |
+| Rewards and API clients | `fastvideo/train/methods/rl/rewards/` | Testable offline reward aggregation is separate from network-backed Gemini/Nano Banana clients. |
+| Image generation/editing | `fastvideo/entrypoints/interleave/generator.py` | Presents a small image backend protocol for FastVideo, Nano Banana, and fake backends. |
+| Runtime orchestration | `fastvideo/entrypoints/interleave/` | Plans steps, calls generator/edit backends, calls critic providers, records traces. |
+| Evaluation | `fastvideo/entrypoints/interleave/evaluation.py` and `trace_eval.py` | Prompt-set execution and saved-trace reporting remain outside training methods. |
+
+This keeps the Qwen actor implementation reusable by SFT, planner GRPO, critic
+GRPO, and inference providers without coupling those paths to a specific
+generator service.
+
+## Validation Matrix
+
+All GPU/model validation below ran on Modal L40S through
+`fastvideo/tests/modal/launch_l40s_job.py`.
+
+| Area | Evidence | Modal app |
+|------|----------|-----------|
+| Initial compatibility service and orchestration tests | `5 passed, 14 warnings`; pre-commit passed. | `ap-cREtgFJyncsIfsXn1B5hLL` |
+| API-backed model/reward wrappers | `27 passed, 14 warnings`; final pre-commit passed. | `ap-QOKlzapm5bSAo3c21lprwv` |
+| Critic backend hardening | `30 passed, 14 warnings`; pre-commit passed. | `ap-DplMFq23YYfBx34e6TcsRc` |
+| Real critic checkpoint smoke | Loaded `InterleaveThinker/Critic-SFT-8B`; generated one rollout; printed `SMOKE_OK`. | `ap-hDxj5MhLgdnGq22mRLjgIK` |
+| FastVideo RL loop skeleton | `22 passed, 14 warnings`; pre-commit passed. | `ap-2Z2sH2UfhMoPmKolG0KY6t` |
+| Shared Qwen actor and planner wrapper | `36 passed, 14 warnings`; pre-commit passed. | `ap-ZapOKZPOmhyMZFxZ0X1fQm` |
+| Real planner checkpoint smoke | Loaded `InterleaveThinker/InterleaveThinker-Planner-8B`; parsed 3 steps; printed `PLANNER_SMOKE_OK`. | `ap-BzH7QxVXoc5XFXBah5cJ2H` |
+| Real critic refactor smoke | Loaded critic wrapper after Qwen base refactor; printed `CRITIC_REFACTOR_SMOKE_OK`. | `ap-NGxUDBNJFiU30Wef0yAQN1` |
+| Planner/critic provider adapters | `20 passed, 14 warnings`; pre-commit passed. | `ap-wfRX2DCt30DN903gETbDpj` |
+| Real provider loop smoke | Real planner and critic with fake generator; printed `INTERLEAVE_PROVIDER_REAL_LOOP_SMOKE_OK`. | `ap-ZABadeyKBuGVcfy67LqmXt` |
+| Native interleave-run CLI | `14 passed, 14 warnings`; pre-commit passed. | `ap-4lOvHURSxKqFmit8TqnhBe` |
+| Real FastVideo generator smoke | FastVideo generator produced a real image through the run CLI; printed `INTERLEAVE_RUN_FASTVIDEO_SMOKE_OK`. | `ap-Tz4VQKximS0bSWx6Fb9aFe` |
+| Dataset normalization | `17 passed, 14 warnings`; pre-commit passed. | `ap-ISuDU2lwc6Pl5NYDZnnBEb` |
+| Planner and critic SFT | `20 passed, 14 warnings`; final pre-commit passed. | `ap-1jmIczO3KwZoP3WtLYOIxc` |
+| Critic GRPO policy loss | Broad InterleaveThinker test set: `28 passed, 14 warnings`; pre-commit passed. | `ap-aYBz0F0ZiQ2nTGndudnGaH` |
+| Real critic RL smoke | Loaded LoRA critic student; generated rollouts; completed one GRPO update; printed `INTERLEAVE_CRITIC_RL_SMOKE_OK`. | `ap-eXMO3I81OcCyxj53XbPWj9` |
+| Reference-policy KL | `16 passed, 14 warnings`; real reference smoke printed `INTERLEAVE_CRITIC_RL_REFERENCE_SMOKE_OK`. | `ap-UQ38OTnymREO9bz0L1QzC5` |
+| Planner GRPO | `37 passed, 14 warnings`; real planner GRPO smoke printed `INTERLEAVE_PLANNER_RL_SMOKE_OK`. | `ap-PDBijC8opxsMiMU0Uc064A` |
+| Prompt-set evaluation workflow | `15 passed, 14 warnings`; pre-commit passed. | `ap-eeQpAgNQvQGi2H8MB0kJCU` |
+| Trace-level evaluation reports | `19 passed, 14 warnings`; pre-commit passed. | `ap-s7ewT9rDZSTdPNhyYrEYO7` |
+
+## Recommended PR Stack
+
+The branch is large and should be split before review:
+
+1. **Inference service and orchestration shell**
+   - `fastvideo/entrypoints/interleave/schema.py`;
+   - generator backend protocol;
+   - compatibility `/edit` service;
+   - `interleave-run` CLI;
+   - fake-backend tests.
+2. **Qwen3-VL actor wrappers**
+   - shared Qwen actor base;
+   - planner and critic wrappers;
+   - data normalization helpers;
+   - real checkpoint load smokes.
+3. **SFT path**
+   - `InterleaveThinkerSFTMethod`;
+   - planner and critic SFT configs;
+   - response-token masking tests.
+4. **Reward and API backend path**
+   - InterleaveThinker reward parser/scorers;
+   - Gemini and Nano Banana wrappers;
+   - fake-client tests.
+5. **GRPO path**
+   - shared GRPO helpers;
+   - `InterleaveThinkerRLMethod`;
+   - critic GRPO, reference KL, planner GRPO;
+   - real one-step LoRA smokes.
+6. **Evaluation and docs**
+   - prompt-set runner;
+   - trace evaluator and HTML report;
+   - examples and design docs.
+
+Each PR should keep the handoff updated until it lands or is superseded.
+
+## Remaining Risks
+
+- **Full 8B training memory:** Real one-step LoRA smokes passed. Full-parameter
+  8B optimizer training and longer distributed runs still need dedicated
+  hardware validation.
+- **Checkpoint/resume:** Configs include checkpoint settings, but planner/critic
+  SFT and GRPO checkpoint/resume smokes are not yet recorded.
+- **Closed-source API drift:** Gemini and Nano Banana wrappers are unit-tested
+  with fake clients. Live API outputs can change and should not be deterministic
+  CI baselines.
+- **EasyR1 parity:** The FastVideo GRPO path matches the important objective
+  pieces used here, but it is not a wholesale EasyR1/Verl port. Distributed
+  rollout semantics and memory strategy should remain explicit in docs.
+- **Native Qwen3-VL port:** The branch uses Transformers Qwen3-VL wrappers. A
+  FastVideo-native Qwen3-VL port should only be considered if conversion,
+  performance, or distributed execution needs justify it.
+- **End-to-end real generator cost:** Real planner/critic and real FastVideo
+  generator pieces have smoke coverage, but large prompt-set runs with all real
+  components can be expensive and should be scheduled intentionally.
+
+## Review Checklist
+
+- Confirm no training code imports from the legacy `fastvideo/training/` stack.
+- Confirm API clients import optional dependencies lazily.
+- Confirm fake-provider tests cover planner, critic, generator, reward, and
+  trace-evaluation behavior without credentials.
+- Confirm real-checkpoint smoke commands use pushed commits, not uncommitted
+  Modal patches.
+- Confirm public YAML configs are parseable and clearly state credential,
+  dataset, and hardware assumptions.
diff --git a/mkdocs.yml b/mkdocs.yml
index 91ed9e202..89d83a88a 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -161,6 +161,7 @@ nav:
     - Debugging: utilities/debugging.md
   - Design:
     - Overview: design/overview.md
+    - InterleaveThinker Integration: design/interleave_thinker.md
     - Training Architecture: design/training_architecture.md
     - Server Contracts:
       - Overview: design/server_contracts/index.md