OpenCE: Closed-Loop Context Engineering Toolkit

OpenCE is a pluggable meta-framework for building closed-loop Context Engineering (CE) systems. It evolves the original community ACE reproduction into a toolkit that can sense → reason → evaluate → evolve its own strategies.

Why Closed-Loop CE?

Classical RAG stacks are open loops: they fetch context once and immediately respond. OpenCE adds two missing pillars:

1. Evaluation – automatically score every LLM response using domain-specific evaluators (ACE Reflector, RAGAS, etc.).
2. Evolution – feed those evaluation signals into long-term memory/strategy modules (ACE Curator, adaptive RAG policies, …).

This creates a self-improving flywheel where every new interaction strengthens future contexts.

The Five Pillars Architecture

OpenCE standardizes five interfaces so that any CE system can be composed as Lego bricks:

| Pillar | Interface | Responsibility | | --- | --- | --- | | Acquisition | IAcquirer | Perception layer (databases, web, LangChain retrievers). | | Processing | IProcessor | Cleans, deduplicates, compresses, or reranks acquired knowledge. | | Construction | IConstructor | Builds the final prompt/context bundle (few-shot selection, dynamic instructions). | | Evaluation | IEvaluator | Scores LLM responses; outputs rich feedback signals. | | Evolution | IEvolver | Consumes evaluation signals to update long-term strategies (playbooks, memories, knobs). |

Each pillar is defined in src/opence/interfaces/ (the soul), implemented natively in src/opence/components/ (the batteries), and can be connected to external ecosystems through src/opence/adapters/ (the glue).

Repository Layout

src/
└── opence/
    ├── interfaces/        # Five pillar ABCs + canonical data models
    ├── components/        # Batteries-included implementations
    │   ├── acquirers/     # Native file readers, etc.
    │   ├── processors/    # Compressors, rerankers …
    │   ├── constructors/  # Few-shot selectors
    │   ├── evaluators/    # ACE reflector integrator
    │   └── evolvers/      # ACE curator + playbook evolver
    ├── models/            # Client abstractions + providers (API, transformers, RWKV)
    ├── methods/           # Composite closed-loop recipes (ACE closed loop, ...)
    ├── adapters/          # LangChain/LlamaIndex adapters (thin wrappers)
    ├── core/              # LLM clients + ClosedLoopOrchestrator
    └── ace/               # Original ACE reproduction (generator/reflector/curator/playbook)

Scripts in scripts/ show end-to-end examples, while tests/ cover the orchestrator, ACE wrappers, and the legacy adapters.

Using uv

This repo is managed with uv. Typical workflow:

# Install deps
uv sync

# Run the test suite
uv run pytest

# Format/lint (optional if you add ruff/black)
uv run ruff check

All code lives under src/, so editable installs (uv pip install -e .) just work if you prefer a global environment.

Minimal Closed-Loop Example

from opence.core import ClosedLoopOrchestrator, DummyLLMClient
from opence.components import (
    FileSystemAcquirer,
    FewShotConstructor,
    SimpleTruncationProcessor,
    KeywordBoostReranker,
    ACEReflectorEvaluator,
    ACECuratorEvolver,
)
from opence.methods.ace import Playbook, Reflector, Curator
from opence.interfaces import LLMRequest

playbook = Playbook()
reflector_llm = DummyLLMClient()
curator_llm = DummyLLMClient()

# Queue deterministic ACE role outputs (see tests for full mocks)
# ...

orchestrator = ClosedLoopOrchestrator(
    llm=DummyLLMClient(),
    acquirer=FileSystemAcquirer("docs"),
    processors=[KeywordBoostReranker(["safety", "fire"]), SimpleTruncationProcessor()],
    constructor=FewShotConstructor(),
    evaluator=ACEReflectorEvaluator(Reflector(reflector_llm), playbook),
    evolver=ACECuratorEvolver(Curator(curator_llm), playbook),
)

result = orchestrator.run(LLMRequest(question="How to investigate industrial fires?"))
print(result.evaluation.feedback)
print(playbook.as_prompt())

Swap out any pillar with your own implementation (or a third-party adapter) to experiment with different CE strategies.

Methods Layer

Many CE techniques require coordinated component bundles. The opence.methods package provides plug-and-play recipes, beginning with ACEClosedLoopMethod, which wires the ACE reflector/curator (evaluation + evolution) with any acquirer/processor/constructor you supply. Methods return fully configured ClosedLoopOrchestrator instances plus metadata, so higher-level runners or CLIs can let users pick --method ace.closed_loop and instantly inherit sensible defaults.

from opence import DummyLLMClient
from opence.methods import ACEClosedLoopMethod

method = ACEClosedLoopMethod(
    generator_llm=DummyLLMClient(),
    reflector_llm=DummyLLMClient(),
    curator_llm=DummyLLMClient(),
)
orchestrator = method.build().orchestrator

MethodRegistry enables registering custom methods so downstream tooling can discover everything available in the toolkit.

Model Providers

opence.models now exposes a provider layer that unifies API-based models (OpenAIModelProvider), local transformers (TransformersModelProvider), RWKV weights (RWKVModelProvider), and deterministic test doubles (DummyModelProvider). Each provider yields an LLMClient; the ClosedLoopOrchestrator automatically accepts either a raw LLMClient or a provider instance, keeping execution uniform regardless of backend.

ACE Method (Legacy + Building Block)

The original ACE reproduction now lives under opence.methods.ace. You still get:

• OfflineAdapter and OnlineAdapter orchestration loops.
• Playbook, Generator, Reflector, Curator, and semantic deduplication utilities.
• Example scripts (scripts/run_local_adapter.py, scripts/run_questions.py) updated to import opence.methods.ace.

You can continue running the classic ACE training scripts:

uv run python scripts/run_local_adapter.py --model-path /path/to/model

The new ACEReflectorEvaluator + ACECuratorEvolver bridge these components into the generic five-pillar orchestrator, so future CE techniques can co-exist with ACE’s evolution dynamics.

Roadmap

• v0.1 – Deliver the closed-loop skeleton (this refactor), document interfaces, publish ACE wrappers ✅
• v0.3 – Add more batteries (compression, dynamic few-shot, scoring adapters, opence.contrib registry).
• v0.5 – Provide benchmark packs + configuration-driven pipelines; ship LangChain/LlamaIndex adapters.
• v1.0 – Promote OpenCE to a community standard with deep OSS ecosystem integrations.

Contributions are welcome across research, engineering, evaluations, and docs. Join us in defining the future of Context Engineering!