dllm-reason 1.4.2

DAG-guided discrete diffusion language models for reasoning

dLLM-Reason

DAG-Guided Discrete Diffusion Language Models for Reasoning

Overview

dLLM-Reason is a research framework that enhances reasoning in discrete diffusion language models (dLLMs) by controlling the token unmasking order via DAG (Directed Acyclic Graph) topological structures.

Core idea: dLLMs generate text by iteratively unmasking tokens. We impose a DAG on unmasking order — edges encode reasoning dependencies — so prerequisite steps are generated before downstream conclusions.

Model Layer          Scheduler Layer          DAG Layer
(what to predict) <-> (where to unmask)  <-> (dependency structure)
MDLM|SEDD|D3PM|LLaDA  13 schedulers          TokenDAG / SpanDAG

Episode Pipeline
  prompt → strategy → generate → evaluate → EpisodeStore → SFT / GRPO / DiFFPO

---

Installation

Requirements

• Python ≥ 3.10
• PyTorch ≥ 2.1 (CUDA recommended for model inference)

From PyPI

# Core package
pip install dllm-reason

# With DAG Library retrieval (FAISS + sentence-transformers)
pip install "dllm-reason[library]"

# With REST API server
pip install "dllm-reason[serve]"

# Full install (all extras)
pip install "dllm-reason[dev,library,serve]"

From Source (recommended for research)

git clone https://github.com/BDeMo/dLLM_Reason.git
cd dLLM_Reason
pip install -e ".[dev,library,serve]"

China mirror (HuggingFace models blocked)

pip install dllm-reason -i https://pypi.tuna.tsinghua.edu.cn/simple
# or set mirror for model downloads:
python scripts/download_models.py --mirror https://hf-mirror.com
python scripts/download_datasets.py --mirror https://hf-mirror.com

Verify installation

python -c "import dllm_reason; print(dllm_reason.__version__)"
dllm-pipeline --help

Optional Extras

Extra	Packages	Purpose
library	faiss-cpu, sentence-transformers, scikit-learn	DAG Library retrieval & semantic search
serve	fastapi, uvicorn, bitsandbytes	REST API server + 4/8-bit quantization
dev	pytest, pytest-cov, ruff	Testing and linting

CLI Commands

After pip install dllm-reason, the following commands are available globally:

Pipeline & Training

Command	Script	Description
dllm-pipeline	run_pipeline.py	End-to-end: download → collect → search → learn → eval
dllm-train	train.py	Pretrain / fine-tune a dLLM
dllm-collect	collect_episodes.py	Collect episodes with multiple strategies
dllm-learn	learn_from_episodes.py	SFT / GRPO / DiFFPO / UnmaskRL from episodes

Evaluation

Command	Script	Description
dllm-eval	evaluate.py	Single-model evaluation on a benchmark
dllm-eval-dags	eval_dags.py	Multi-strategy × multi-benchmark evaluation
dllm-bench-schedulers	benchmark_schedulers.py	Compare all 11 schedulers side-by-side
dllm-episodes	inspect_episodes.py	Inspect / export EpisodeStore

DAG Search & Management

Command	Script	Description
dllm-search	search_dag.py	DAG structure search (greedy / evolutionary)
dllm-analyze-dag	analyze_dag.py	DAG structural statistics + visualizations
dllm-templates	generate_templates.py	Generate and save named DAG templates
dllm-merge-dags	merge_dags.py	Merge multiple DAGs (union / intersection / weighted)

DAG Library

Command	Script	Description
dllm-library	manage_library.py	CRUD + retrieval for the DAG Library
dllm-feedback	add_feedback.py	Add benchmark scores / human ratings / Elo

Serving & Visualization

Command	Script	Description
dllm-serve	serve.py	REST API server with hot-switching strategies
dllm-webui	webui.py	Interactive Web UI dashboard
dllm-viz	visualize_dag.py	Render a DAG to PNG / interactive plot
—	search_dag_live.py	DAG search with real-time web dashboard

---

Quick Start

# ── Step 0: Install ───────────────────────────────────────────────
pip install "dllm-reason[library,serve]"

# ── Step 1: Download model and datasets ──────────────────────────
python scripts/download_models.py              # → checkpoints/llada-instruct/
python scripts/download_datasets.py            # → datasets/

# China mirror
python scripts/download_models.py   --mirror https://hf-mirror.com
python scripts/download_datasets.py --mirror https://hf-mirror.com

# ── Step 2: Run the full pipeline (one command) ───────────────────
dllm-pipeline \
    --checkpoint checkpoints/llada-instruct \
    --dataset gsm8k \
    --stages download collect search learn eval \
    --rl_mode grpo

# ── Step 3: Smoke-test evaluation ────────────────────────────────
dllm-eval-dags --dags confidence --benchmarks gsm8k --num_samples 5

# ── Step 4: Start the REST API server ────────────────────────────
dllm-serve --model_id checkpoints/llada-instruct --quantize 4bit

---

Usage

All parameters live in configs/eval_default.yaml. CLI flags always override the config.

Evaluation

# Default run (LLaDA + confidence)
bash scripts/run_eval.sh

# Direct CLI — pick strategies and benchmarks
dllm-eval-dags \
    --dags confidence entropy adaptive_dynamic cot \
    --benchmarks gsm8k math mbpp humaneval \
    --num_steps 128 --num_samples 100 \
    --save_outputs \
    --output_dir results/my_run

# Per-strategy convenience scripts
bash scripts/runs/confidence.sh       # highest-confidence first (LLaDA default)
bash scripts/runs/random.sh           # uniform random
bash scripts/runs/entropy.sh          # lowest-entropy first
bash scripts/runs/semi_ar.sh          # block-by-block L->R
bash scripts/runs/linear.sh           # strict left-to-right
bash scripts/runs/cot.sh              # Chain-of-Thought DAG
bash scripts/runs/skeleton.sh         # skeleton-then-detail DAG
bash scripts/runs/bidirectional.sh    # both ends toward center
bash scripts/runs/answer_first.sh     # answer region first
bash scripts/runs/all_strategies.sh   # all 13 strategies in one run
bash scripts/runs/full_comparison.sh  # 13 strategies x 10 benchmarks

# All scripts pass extra args through:
bash scripts/runs/cot.sh --benchmarks mbpp humaneval --num_samples 100 --cot_steps 6

Single-Prompt Inference

python scripts/infer_llada.py \
    --model_id checkpoints/llada-instruct \
    --prompt "What is 7 * 8?" \
    --num_steps 128 --block_length 32 --temperature 0.0

REST API Serving

# Install serving extras
pip install "dllm-reason[serve]"

# Start server (bfloat16 / port 8000)
dllm-serve --model_id checkpoints/llada-instruct

# With 4-bit quantization (~5 GB VRAM)
dllm-serve --model_id checkpoints/llada-instruct --quantize 4bit

# Generate with any strategy — hot-switchable, no model reload
curl -X POST http://localhost:8000/generate \
  -H "Content-Type: application/json" \
  -d '{"prompt": "What is 7*8?", "strategy": "adaptive_dynamic", "max_new_tokens": 256}'

# List strategies
curl http://localhost:8000/strategies

# Health check
curl http://localhost:8000/health

Save Per-Sample Outputs

dllm-eval-dags --dags confidence cot adaptive_dynamic \
    --save_outputs \
    --output_dir results/detailed

# Output files per (benchmark, strategy):
#   {bench}_{dag}_samples.json   — prompt, generated, ground truth, pass/fail
#   {bench}_{dag}_samples.xlsx   — same in spreadsheet format
#   {bench}_{dag}_trajectory.json — per-step unmasking states (with --record_trajectory)

Web UI (Interactive Dashboard)

# Install serving extras
pip install "dllm-reason[serve]"

# Launch Web UI (loads model + opens browser dashboard)
dllm-webui --model_id checkpoints/llada-instruct --port 7860

# With quantization
dllm-webui --model_id checkpoints/llada-instruct --quantize 4bit

# Results viewer only (no model, no GPU needed)
dllm-webui --no_model --port 7860

Features:

• Generate: Interactive text generation with strategy selector
• Compare: Side-by-side comparison of multiple strategies on the same prompt
• Trajectory: Visualize step-by-step unmasking progression
• Results: Browse and compare benchmark results (reads results/ directory)

DAG Search with Live Web Dashboard

# Evolutionary search — opens http://localhost:8765 automatically
python scripts/search_dag_live.py \
    --model llada \
    --checkpoint checkpoints/llada-instruct \
    --dataset gsm8k \
    --method evolutionary \       # greedy | evolutionary | rl_policy | differentiable
    --budget 100 \
    --fitness accuracy \          # accuracy | perplexity | combined
    --seq_len 256 \
    --port 8765

# Seed population from templates (new)
python scripts/search_dag_live.py --method evolutionary \
    --init_templates              # default set: cot skeleton bidirectional answer_first empty

python scripts/search_dag_live.py --method evolutionary \
    --init_templates cot skeleton bidirectional answer_first

# Greedy warm-start: evaluate all templates, start from best
python scripts/search_dag_live.py --method greedy \
    --init_templates cot skeleton answer_first

# 9 available template names:
# cot  skeleton  bidirectional  answer_first  interleaved
# linear  empty  random_low  random_high

Episode Collection

Collect (prompt, strategy, output, evaluation) records into a persistent SQLite store.

# Single prompt
python scripts/collect_episodes.py \
    --model_id checkpoints/llada-instruct \
    --prompt "What is 12 * 15?" \
    --ground_truth "180" \
    --task_type math \
    --strategy cot confidence \   # collect for BOTH strategies in one run
    --db_path episodes/gsm8k.db

# Dataset (JSONL)
python scripts/collect_episodes.py \
    --dataset_path data/gsm8k_test.jsonl \
    --prompt_field problem --answer_field answer \
    --n_samples 500 \
    --strategy confidence cot adaptive_dynamic \
    --eval_mode auto              # auto | manual | none

Learning from Episodes

Fine-tune the model on stored episodes.

# Print stats only
python scripts/learn_from_episodes.py --db_path episodes/gsm8k.db \
    --model_id none --mode stats

# SFT on correct episodes
python scripts/learn_from_episodes.py \
    --db_path episodes/gsm8k.db \
    --model_id checkpoints/llada-instruct \
    --mode sft --task_type math --dag_aware \
    --epochs 3 --lr 1e-5 \
    --output_dir checkpoints/sft-math

# GRPO (group relative policy optimisation)
python scripts/learn_from_episodes.py \
    --mode grpo --kl_coeff 0.01 \
    --output_dir checkpoints/grpo-math

# DiFFPO — PPO with importance-ratio clipping + joint sampler training
# Reference: Zhao et al. 2024  https://arxiv.org/abs/2510.02212
python scripts/learn_from_episodes.py \
    --mode diffppo \
    --ppo_clip_eps 0.2 \
    --train_sampler \             # jointly train adaptive step-budget controller
    --min_steps 8 --max_steps 128 \
    --step_budget_lambda 0.1 \
    --output_dir checkpoints/diffppo-math

Mode	Data used	Algorithm	Best for
sft	correct only	Cross-entropy	Fast, clean data
grpo	all evaluated	GRPO group advantage	Contrastive (correct vs wrong)
diffppo	all evaluated	PPO clip + step controller	Accuracy + inference speed Pareto

LaTeX Table Generation

# Generate publication-ready comparison table from results
python scripts/generate_latex_table.py results/summary.json --output paper_table.tex

Config File

# configs/eval_default.yaml
model:
  model_id: "checkpoints/llada-instruct"
  torch_dtype: "bfloat16"

inference:
  num_steps: 128
  block_length: 32
  temperature: 0.0
  cfg_scale: 0.0
  remasking: "low_confidence"
  max_new_tokens: 128

benchmarks:
  benchmarks: ["mbpp", "humaneval"]
  num_samples: null       # null = full dataset

dags:
  dags: ["confidence"]
  # choices: confidence | random | entropy | semi_ar | maskgit_cosine
  #          | critical_token_first | curriculum | linear | cot
  #          | skeleton | bidirectional | answer_first | adaptive_dynamic

---

13 Unmasking Strategies

Strategy	Type	Description
confidence	Flat	Unmask highest model confidence first (LLaDA default)
random	Flat	Uniform random unmasking
entropy	Flat	Lowest-entropy (most certain by distribution) first
semi_ar	Flat	Block-by-block left-to-right, confidence within block
maskgit_cosine	Flat	MaskGIT cosine schedule: more tokens early, fewer later
critical_token_first	Flat	Highest KL divergence from uniform (most influential) first
curriculum	Flat	Easy tokens first (high confidence + low entropy)
linear	Flat	Strict left-to-right sequential
cot	DAG	Chain-of-Thought: reasoning segments before answer
skeleton	DAG	Structural tokens first, then fill details
bidirectional	DAG	Both ends toward center
answer_first	DAG	Answer region unmasked before reasoning
adaptive_dynamic	Dynamic	Dynamic soft DAG — constructs pairwise influence graph at runtime (ours)

---

10 Benchmarks

Benchmark	Type	Metric	Dataset
mbpp	Code generation	pass@1	Google MBPP (Python)
humaneval	Code generation	pass@1	OpenAI HumanEval (Python)
gsm8k	Math reasoning	exact match	Grade school math
math	Competition math	exact match	MATH (extracts \boxed{})
mmlu	Knowledge	accuracy	57-subject multitask
hotpotqa	Multi-hop QA	EM / F1	Multi-hop reasoning
arc	Science reasoning	accuracy	ARC-Challenge
prontoqa	Logic reasoning	accuracy	Formal logic
gpqa	PhD-level science	accuracy	GPQA Diamond subset
aime	Competition math	accuracy	AMC/AIME (integer 000-999)

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Project Structure

src/dllm_reason/
  models/          MDLM, SEDD, D3PM, LLaDA (4 dLLMs)
  graph/           TokenDAG, SpanDAG, 9 templates + registry, constraints, visualization
  scheduler/       13 unmasking strategies (8 flat + 4 DAG + 1 adaptive dynamic)
  search/          Evolutionary, Greedy, RL Policy, NOTEARS, E2E DAG, NAS (6 search methods)
  inference/       DiffusionSampler (auto-pad, early-stop), DAGSampler
  training/        Pretrain, DAG-aware, Fine-tune, DiffuGRPO, DiFFPO
  eval/            10 benchmark evaluators, metrics, DAG analysis
  library/         DAGEntry + DAGStore (retrieval/fusion/feedback/merge)
                   DAGEpisode + EpisodeStore  ← episode pipeline
  data/            Dataset loaders (GSM8K, MATH, ARC, ProntoQA, ...)
  utils/           Registry, logging, distributed

configs/           31 YAML configs (model, graph, search, task, eval, experiment, library)
scripts/           serve.py  search_dag_live.py  collect_episodes.py
                   learn_from_episodes.py  + eval / train / viz scripts
                   runs/  16 shell convenience scripts
tests/             DAG, schedulers, models, library (4 test suites)
notebooks/         DAG exploration, results analysis
docs/              API_REFERENCE.md  REFERENCES.md  deployment.md  tutorial  V1.0_RELEASE.md
REFERENCES.md      All cited papers (root-level, kept in sync with docs/)

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Key Components

TokenDAG

Boolean adjacency matrix on GPU. Edge (i, j) = "position i must unmask before j".

from dllm_reason.graph.dag import TokenDAG

dag = TokenDAG.linear_chain(seq_len=256)
ready = dag.ready_positions(is_unmasked)  # one batched GPU op

9 named templates accessible via unified registry:

from dllm_reason.graph.templates import build_all_templates, build_template, TEMPLATE_NAMES
# TEMPLATE_NAMES = ['cot','answer_first','skeleton','bidirectional',
#                   'interleaved','linear','empty','random_low','random_high']

templates = build_all_templates(seq_len=128, device="cuda")
dag = build_template("cot", seq_len=128)

SpanDAG

Coarse-grained DAG over token spans — reduces search space by span_size^2.

from dllm_reason.graph.span_dag import SpanDAG

sdag = SpanDAG.cot(num_spans=8, span_size=32, num_reasoning_steps=4)
token_dag = sdag.to_token_dag()  # expand for scheduler

DAGScheduler

DAG constraints inject at scheduler layer — models need zero modification.

from dllm_reason.scheduler.dag_scheduler import DAGScheduler
scheduler = DAGScheduler(dag, sub_strategy="confidence_topk")

Adaptive Dynamic DAG (Novel)

Constructs soft dependency graph at runtime based on pairwise influence between masked positions.

from dllm_reason.scheduler.adaptive_dynamic_scheduler import AdaptiveDynamicScheduler
scheduler = AdaptiveDynamicScheduler(influence_threshold=0.3, momentum=0.5)

DAG Search (6 Methods)

Automatically discover optimal DAG structures.

# Evolutionary search — templates seed the initial population automatically
from dllm_reason.search.evolutionary import EvolutionarySearch
searcher = EvolutionarySearch(
    population_size=20,
    init_templates=["cot", "skeleton", "bidirectional"],  # None = default set
    library=dag_store,
)
result = searcher.search(model, eval_fn, seq_len=256, budget=200)

# Greedy search — warm-start from the best template
from dllm_reason.search.greedy import GreedyEdgeSearch
searcher = GreedyEdgeSearch(init_templates=["cot", "skeleton", "answer_first"])
result = searcher.search(model, eval_fn, seq_len=256, budget=100)

# End-to-end DAG learning (differentiable, jointly with task loss)
from dllm_reason.search.e2e_dag_learner import E2EDAGLearner, E2EConfig
learner = E2EDAGLearner(config=E2EConfig(lr_dag=3e-3))
result = learner.search(model, eval_fn, seq_len=256, budget=200)

# NAS-style search (DARTS supernet or ENAS controller)
from dllm_reason.search.nas_search import NASDAGSearch, NASConfig
searcher = NASDAGSearch(config=NASConfig(mode="supernet", span_size=16))
result = searcher.search(model, eval_fn, seq_len=256, budget=200)

Method	Type	Description
Greedy	Black-box	Add/remove edges iteratively
Evolutionary	Black-box	Population-based with tournament selection
RL Policy	Black-box	GRU + REINFORCE for edge construction
Differentiable	Gradient	NOTEARS continuous relaxation
E2E DAG Learning	Gradient	Joint DAG + task loss optimization
NAS SuperNet/Controller	Gradient/RL	DARTS or ENAS-style architecture search

DAG Library

Persistent storage + retrieval + feedback for DAG structures.

• DAGStore: SQLite + FAISS vector index for DAGEntry records
• Retrieval: 3 channels (semantic, structural, performance)
• Fusion: 4 strategies (weighted, RRF, max, voting)
• Feedback: 3 sources (auto benchmark, human rating, Elo tournament)
• Merge: 3 strategies (union, intersection, weighted)

All components independently toggleable for ablation. 7 preset configs in configs/library/.

Episode Pipeline

Full loop: collect interaction records → store → learn from them.

from dllm_reason.library.episode import DAGEpisode, EpisodeStore

store = EpisodeStore("episodes/gsm8k.db")
ep = DAGEpisode(prompt="...", task_type="math", strategy_name="cot",
                output="...", ground_truth="42")
store.add(ep)
store.update_eval(ep.episode_id, correct=True, score=1.0)

# Paginated training iterator (memory-safe)
for ep in store.iter_for_training(task_type="math", correct_only=True):
    ...

store.print_stats()

Scripts: collect_episodes.py → learn_from_episodes.py (modes: sft / grpo / diffppo)

RL Training

Three algorithms in src/dllm_reason/training/rl_train.py:

Class	Algorithm	Key feature
DiffuGRPO	GRPO	Group-relative advantage, no importance weights
DiFFPO	PPO + joint sampler	Importance-ratio clipping + StepBudgetController

DiFFPO (Zhao et al. 2024, arXiv:2510.02212) jointly trains a lightweight MLP controller that predicts the optimal number of denoising steps per prompt, improving the accuracy–compute Pareto frontier.

---

Models

Model	Type	Reference
LLaDA	LLaMA-3 masked diffusion (8B)	Nie et al., 2025
MDLM	Absorbing-state continuous-time	Sahoo et al., 2024
SEDD	Score-entropy discrete diffusion	Lou et al., 2024
D3PM	Discrete-time structured transitions	Austin et al., 2021

---

Configuration

All configs use YAML + Hydra/OmegaConf.

Directory	Contents
configs/model/	Model hyperparameters (mdlm, sedd, d3pm, llada)
configs/graph/	DAG template parameters
configs/search/	Search algorithm settings
configs/task/	Dataset configs
configs/eval/	Benchmark settings
configs/experiment/	End-to-end experiment combinations
configs/library/	DAG Library ablation variants
configs/eval_default.yaml	Default evaluation config

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Documentation

• Tutorial: pip install + all-strategies evaluation
• Deployment Guide: REST API, Docker, quantization
• API Reference
• References: all cited papers · also at REFERENCES.md
• Version History

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License

MIT License. See LICENSE for details.