dlightrag 1.5.3

Multimodal RAG with knowledge graph and contextual intelligence

DlightRAG

DlightRAG is a multimodal RAG service built on LightRAG main. It ingests documents and images into isolated workspaces, lets LightRAG own parser sidecars, document status, chunks, knowledge graph, and vectors, and adds PostgreSQL metadata filtering, BM25, direct image retrieval, and cited answers.

Use it as a Web UI, REST API, Python SDK, or MCP server for AI agents.

Status: Python 3.12+. Storage: PostgreSQL 18 with pgvector, Apache AGE, and pg_textsearch. License: Apache-2.0.

Start Here

Most local work uses this shape:

Browser / curl / Python / MCP client
  -> DlightRAG API + Web UI  (Docker or native, port 8100)
  -> PostgreSQL 18           (Docker, port 5432)
  -> LightRAG main           (parser sidecars, KG, vectors, doc status)
  -> DlightRAG stores        (metadata index, BM25, workspace/role metadata)

Prerequisites

• Docker Desktop for the recommended local setup.
• Python 3.12+ and uv for native development or SDK use.
• Model credentials for the providers configured in config.yaml.
• A multimodal embedding model. The checked-in default is voyage-multimodal-3.5.
• A local MinerU HTTP sidecar for PDF, PPTX, XLSX, and other non-DOCX document parsing.

If you do not use Docker, provide PostgreSQL 18 with pgvector, Apache AGE, and pg_textsearch installed and preloaded as required by docs/PG.md.

Recommended Local Setup

1. Create .env and fill credentials only:

git clone https://github.com/hanlianlu/dlightrag.git
cd dlightrag
cp .env.example .env

At minimum, set the LLM and embedding API keys needed by config.yaml:

DLIGHTRAG_LLM__DEFAULT__API_KEY=...
DLIGHTRAG_EMBEDDING__API_KEY=...
DLIGHTRAG_LLM__ROLES__EXTRACT__API_KEY=...
DLIGHTRAG_LLM__ROLES__KEYWORD__API_KEY=...

Normal settings such as model names, parser routing, ports, logging, PostgreSQL endpoints, and retrieval knobs live in config.yaml.

The default document route uses LightRAG native parsing for DOCX and MinerU for other document types. config.yaml is local-first and points native DlightRAG at http://127.0.0.1:8210. If ArtRAG already has a MinerU service running on port 8210, DlightRAG can reuse it.

2. Start a local MinerU sidecar for document parsing if one is not already running:

cp .env.mineru.example .env.mineru
make mineru-install
make mineru-api

The helper creates a dedicated .venv-mineru so MinerU's ML dependencies do not enter DlightRAG's runtime environment. With no explicit MINERU_INSTALL_EXTRAS, the installer uses mineru[core,mlx] on Apple Silicon and mineru[core] elsewhere. .env.mineru.example defaults to core,mlx for this local development setup. Keep DlightRAG runtime parser settings in config.yaml. The Makefile targets are the stable public entry points; the implementation lives under scripts/mineru/. On GPU servers, prefer MinerU's official Docker Compose api or router profile; set parser_sidecars.mineru.local_endpoint to that service, usually http://127.0.0.1:8000 or http://127.0.0.1:8002.

On macOS, you can keep the sidecar running through launchd:

make mineru-service-install
make mineru-service-status
make mineru-service-logs

3. Start the service stack:

docker compose up -d
docker compose ps
curl http://localhost:8100/health

docker compose up -d starts:

Service	Purpose	Host Port
dlightrag-api	REST API + Web UI	8100
dlightrag-mcp	MCP streamable HTTP server	127.0.0.1:8101
postgres	PostgreSQL 18 + pgvector + AGE + pg_textsearch	5432

When DlightRAG itself runs in Docker, compose maps MINERU_LOCAL_ENDPOINT inside the app containers to http://host.docker.internal:8210 by default. Override MINERU_DOCKER_LOCAL_ENDPOINT when the MinerU API is attached to a Docker network, for example http://mineru-api:8000.

4. Open the Web UI:

http://localhost:8100/web/

Use the Files panel to upload documents or images, then ask a question in the chat composer. This is the easiest first ingest path for Docker because the uploaded file is staged inside DlightRAG's managed runtime volume at working_dir/inputs/<workspace>/, which is also the INPUT_DIR root used by LightRAG parser workers.

First API Calls

Local-source ingestion paths must be visible to the API process. For native API runs, pass a normal host path. For Docker, either use the Web UI upload or mount a host directory into the API container.

curl -X POST http://localhost:8100/ingest \
  -H "Content-Type: application/json" \
  -d '{"source_type": "local", "path": "/absolute/path/visible/to/api"}'

curl -X POST http://localhost:8100/retrieve \
  -H "Content-Type: application/json" \
  -d '{"query": "What are the key findings?"}'

curl -X POST http://localhost:8100/answer \
  -H "Content-Type: application/json" \
  -d '{"query": "What are the key findings?", "stream": false}'

Full request and response details live in docs/response-schema.md.

Architecture

_{Source: docs/architecture.drawio (runtime flow) and docs/module-layers.md (module layers).}

Mental Model

DlightRAG has one runtime RAG path:

source file
  -> LightRAG parser sidecars
       text, tables, equations, document-derived images
  -> LightRAG ingest
       chunks, entities, relationships, graph, text vectors, doc status
  -> direct image embedding
       native images and parser-extracted image sidecars into LightRAG chunks/vectors
  -> DlightRAG metadata/BM25 layer
       declared metadata index, in-filter scope, pg_textsearch BM25
  -> retrieval
       LightRAG mix + direct image vectors + BM25 + RRF + rerank + citations

Core responsibilities:

Layer	Responsibility
API, MCP, Web UI	Interface adapters, auth, uploads, streaming responses.
RAGServiceManager	Multi-workspace routing, federation, health, read-after-write barriers.
RAGService	Per-workspace lifecycle, ingest, retrieve, answer, reset.
LightRAG	Parser routing, sidecars, chunks, KG entities/relationships, vectors, doc status, mix retrieval.
DlightRAG stores	Declared metadata index, BM25 state, workspace/role metadata.
Model adapters	LLM, VLM, embedding, asymmetric task routing, reranking.

Long-form pipeline notes are in docs/retrieval_answer_mechanism.md.

Retrieval Shape

DlightRAG always uses LightRAG mix as the base retrieval mode. The DlightRAG hybrid layer is separate from LightRAG's hybrid mode:

query
  -> intent-aware query planning and metadata filtering
  -> LightRAG mix retrieval
  -> direct image retrieval when query images are present
  -> pg_textsearch BM25 over the same candidate scope
  -> RRF fusion
  -> rerank
  -> answer generation with citations

Metadata filters are in-filtered. Explicit API/user filters are strict; if they match no candidates, retrieval returns no matches. LLM-inferred filters can fall back to unfiltered retrieval when they over-infer and resolve to an empty candidate set.

Operating Modes

Docker API + Web UI

Recommended for local service use:

docker compose up -d
docker compose logs -f dlightrag-api

The API and Web UI share port 8100; the Web UI is at /web/. The MCP server is mapped to 127.0.0.1:8101 by default.

For local model servers running on the host machine, use host.docker.internal in base_url settings rather than localhost.

Native API

Use this when DlightRAG runs outside Docker while PostgreSQL stays in Docker:

docker compose up -d postgres
uv sync
uv run dlightrag-api

Native runs can ingest host paths directly because the API process sees the same filesystem as your shell.

Python SDK

Install and run against your configured PostgreSQL and model providers:

uv add dlightrag        # or: pip install dlightrag
cp .env.example .env

import asyncio
from dotenv import load_dotenv
from dlightrag import DlightragConfig, RAGServiceManager

load_dotenv()

async def main():
    config = DlightragConfig()
    manager = await RAGServiceManager.create(config)
    try:
        workspace = "research_notes"
        await manager.acreate_workspace(workspace, display_name="Research Notes")
        await manager.aingest(workspace, source_type="local", path="./docs")

        contexts = await manager.aretrieve("What are the key findings?", workspace=workspace)
        print(contexts.contexts)

        answer = await manager.aanswer("What are the key findings?", workspace=workspace)
        print(answer.answer)
    finally:
        await manager.close()

asyncio.run(main())

MCP Server

Use stdio when the agent starts DlightRAG as a subprocess:

uv tool install dlightrag
cp .env.example .env

{
  "mcpServers": {
    "dlightrag": {
      "command": "uvx",
      "args": ["dlightrag-mcp", "--env-file", "/absolute/path/to/.env"]
    }
  }
}

Use streamable HTTP when multiple clients connect to a running service:

DLIGHTRAG_MCP_TRANSPORT=streamable-http \
DLIGHTRAG_MCP_HOST=127.0.0.1 \
dlightrag-mcp

MCP tools: retrieve, answer, ingest, list_files, delete_files, list_workspaces, create_workspace, and delete_workspace.

Primary / Replica Process Roles

For production concurrency, separate write and read processes:

Ingest/admin workers -> primary PostgreSQL
Query workers        -> hot standby / read replica PostgreSQL
Primary              -> physical streaming replication -> replica

Set runtime_role: query on read-only query workers and configure postgres_replica_*. Query role attaches to existing LightRAG and DlightRAG schema without DDL and rejects ingest, delete, metadata update, retry, and reset operations.

Set read_after_write_mode: wait_for_replay on ingest/admin workers when a write acknowledgement must wait until the replica has replayed the current primary WAL LSN. Default eventual favors throughput and allows short replica lag.

Details: docs/database-role-architecture.md.

Configuration

Configuration uses structured app settings in config.yaml and secrets or deployment-only overrides in .env.

Priority:

constructor args > environment variables > .env > config.yaml > defaults

DlightRAG-owned environment variables use the DLIGHTRAG_ prefix. Double underscores address nested objects:

DLIGHTRAG_LLM__DEFAULT__API_KEY=...
DLIGHTRAG_EMBEDDING__API_KEY=...
DLIGHTRAG_RERANK__API_KEY=...

Parser sidecar defaults live in config.yaml under parser_sidecars. DlightRAG bridges those typed settings into LightRAG's upstream env names at startup. .env.example keeps only secrets such as provider keys, PostgreSQL passwords, and DLIGHTRAG_PARSER_SIDECARS__MINERU__API_TOKEN. Docker-only sidecar endpoint overrides use MINERU_DOCKER_LOCAL_ENDPOINT.

MinerU Local Sidecar

DlightRAG delegates MinerU parsing to LightRAG main. It does not ship a separate MinerU client or parser path. The local contract is the MinerU HTTP API used by LightRAG:

POST /tasks
GET  /tasks/{task_id}
GET  /tasks/{task_id}/result
GET  /health

Recommended defaults in config.yaml:

Setting	Default	Why
parser_sidecars.mineru.api_mode	local	Keeps document parsing local by default.
parser_sidecars.mineru.local_endpoint	http://127.0.0.1:8210	Reuses ArtRAG or DlightRAG's local make mineru-api sidecar.
parser_sidecars.mineru.local_backend	hybrid-auto-engine	Uses MinerU's local hybrid parser when the service supports it.
parser_sidecars.mineru.local_parse_method	auto	Lets MinerU choose text-layer extraction vs OCR per page.
parser_sidecars.mineru.enable_table / enable_formula	true	Preserves table and equation extraction for LightRAG ingest.

DlightRAG applies a narrow LightRAG parser hygiene patch at startup when the current upstream MinerU IR builder still indexes page furniture. The patch drops page furniture families such as headers, footers, page numbers, margin notes, page footnotes, and discarded blocks before LightRAG builds chunks, while preserving semantic and multimodal blocks such as text, lists, code, tables, equations, images, and charts.

The official MinerU API remains available by explicitly changing parser_sidecars.mineru.api_mode: official in config.yaml and setting DLIGHTRAG_PARSER_SIDECARS__MINERU__API_TOKEN in .env; it is not the checked-in default.

Local MinerU service installation uses .env.mineru, not .env:

MINERU_INSTALL_EXTRAS=core,mlx
MINERU_API_HOST=127.0.0.1
MINERU_API_PORT=8210

Those keys affect only make mineru-install, make mineru-api, and the macOS LaunchAgent helper. They do not change DlightRAG parser behavior; align parser_sidecars.mineru.local_endpoint in config.yaml if you change the host or port. If you update from an older local checkout that already installed the LaunchAgent, run make mineru-service-install once so launchd points at the current scripts/mineru/api.sh helper.

Model Providers

LLM provider blocks support:

Provider	SDK	Typical use
openai	AsyncOpenAI	OpenAI, Azure OpenAI, OpenRouter, Ollama, Xinference, local OpenAI-compatible endpoints.
anthropic	Anthropic SDK	Claude models.
gemini	Google GenAI SDK	Gemini models.

LightRAG-aligned role overrides live under llm.roles:

Role	What it drives
extract	KG entity and relationship extraction during ingest.
keyword	LightRAG retrieval keyword extraction.
query	Query planning and answer generation.
vlm	Visual analysis for image, table, equation, and drawing sidecars.

Unset roles fall back to llm.default.

The checked-in defaults route extract and keyword through DeepSeek's OpenAI-compatible Chat Completions endpoint using deepseek-v4-flash with thinking disabled through model_kwargs.thinking.type: disabled. query and vlm continue to fall back to the multimodal default LLM unless explicitly overridden.

Embeddings

The embedding model must be multimodal. Text chunks, native images, and parser-extracted image sidecars must share one vector space.

Provider	Example model	Notes
voyage	voyage-multimodal-3.5	Default provider; recommended dimension 1024.
dashscope_qwen	qwen3-vl-embedding-2b	DashScope multimodal payloads.
qwen_openai_compatible	qwen3-vl-embedding-2b via LM Studio or vLLM	OpenAI-compatible local endpoint.
gemini	gemini-embedding-2	Uses symmetric fallback when task routing is unavailable.
jina	jina-embeddings-v4	Uses task routing when supported.

embedding.asymmetric: auto enables provider task routing when available. Otherwise DlightRAG relies on LightRAG's symmetric fallback. Changing embedding.dim after indexing requires clearing the workspace and rebuilding vector indexes.

Rerank Image Budget

Reranking happens before answer-context packing. Multimodal rerankers therefore use their own image payload budget instead of relying on answer.* limits:

Setting	Default	Meaning
rerank.image_max_bytes	1500000	Maximum compressed binary bytes per rerank image before base64 expansion.
rerank.image_max_total_bytes	8000000	Maximum compressed binary image bytes per rerank model request.
rerank.image_max_px	1280	Maximum long edge after rerank-stage bounding.
rerank.image_min_px	768	Long-edge floor before oversized rerank images are skipped.
rerank.image_quality	86	Initial JPEG quality for recompressed rerank images.
rerank.image_min_quality	76	JPEG quality floor before oversized rerank images are skipped.

Answer Image Budget

Answer generation uses one shared image budget for user query_images and retrieved visual chunks. The defaults favor VLM understanding over aggressive payload minimization:

Setting	Default	Meaning
answer.candidate_top_k	60	Retrieval candidates fetched for /answer before final prompt packing.
answer.context_top_k	30	Maximum chunks kept in the final answer prompt.
answer.max_images	6	Maximum images sent to the answer model.
answer.image_max_bytes	3000000	Maximum compressed binary bytes per image before base64 expansion.
answer.image_max_total_bytes	24000000	Maximum compressed binary bytes across all answer images.
answer.image_max_px	1536	Maximum long edge after bounding.
answer.image_min_px	1024	Long-edge floor before oversized images are skipped.
answer.image_quality	88	Initial JPEG quality for recompressed images.
answer.image_min_quality	72	JPEG quality floor before oversized images are skipped.

Already-budgeted JPEG, PNG, and WebP payloads pass through unchanged. Images that cannot fit without crossing the quality or size floor are skipped instead of being sent as low-fidelity previews.

For /answer, DlightRAG retrieves answer.candidate_top_k candidates, reranks them, then packs up to answer.context_top_k chunks into the prompt. In LightRAG terms, this over-fetch maps to QueryParam.chunk_top_k; top_k remains the independent KG entity/relationship breadth. User query_images occupy the shared image budget first. Pure visual chunks whose image cannot be sent are skipped and the packer backfills from later candidates; mixed text+image chunks keep their text. /answer therefore returns contexts and sources aligned with what the answer model saw. Use /retrieve when you need the broader pre-answer retrieval set.

Metadata Filtering

Metadata is explicit-schema first:

• Declared fields are normalized and filterable.
• Undeclared metadata can be stored as JSONB enrichment, but is not filterable by default.
• Explicit API/user filters are strict and never fall back to global retrieval.
• LLM-inferred filters include confidence/evidence for observability; empty inferred candidates fall back to unfiltered retrieval.
• Non-empty inferred candidates constrain both semantic and BM25 retrieval.

Storage

DlightRAG's supported core storage stack is PostgreSQL 18 only:

Component	Backend
Vector store	PGVectorStorage with pgvector
Graph store	PGGraphStorage with Apache AGE
KV store	PGKVStorage
Document status	PGDocStatusStorage
BM25	pg_textsearch

Default vector indexing uses pg_vector_index_type: HNSW with VECTOR(dim). HNSW_HALFVEC is explicit opt-in and should only be used after deciding the workspace embedding dimension and rebuilding indexes.

pg_hnsw_ef_search and postgres_session_settings are applied to both the LightRAG PostgreSQL pool and DlightRAG's domain-store pool. Server-level PostgreSQL memory and WAL settings remain deployment configuration in docker-compose.yml or your managed Postgres service.

The checked-in Docker stack also sets shm_size: 8gb for both PostgreSQL primary and replica. That controls container /dev/shm for HNSW builds and is separate from shared_buffers, work_mem, and maintenance_work_mem.

More PostgreSQL notes: docs/PG.md.

Workspaces

Each workspace is isolated by PostgreSQL workspace columns and LightRAG graph namespace. Federated search can query multiple workspaces, but those workspaces must use compatible embedding models and dimensions.

Auth And Observability

Auth

If anyone other than you can reach REST port 8100 or MCP port 8101, enable bearer auth:

openssl rand -base64 32
echo "DLIGHTRAG_API_AUTH_TOKEN=<generated>" >> .env

Set auth_mode: simple in config.yaml.

Clients send:

Authorization: Bearer <generated>

The same token guards REST and MCP. JWT auth is also available through auth_mode: jwt.

Langfuse

Langfuse tracing is optional. If both keys are absent, tracing is a no-op.

DLIGHTRAG_LANGFUSE_PUBLIC_KEY=pk-...
DLIGHTRAG_LANGFUSE_SECRET_KEY=sk-...

Set langfuse_host and langfuse_export_external_spans in config.yaml when the defaults are not right for the deployment.

For local self-hosted Langfuse:

make langfuse-up
make langfuse-health
make langfuse-logs
make langfuse-down

The helper keeps the Langfuse stack outside this repo at ../langfuse-local and writes matching local project keys into both env files. Its local-only implementation is grouped under scripts/langfuse/; use the Makefile targets instead of calling those helpers directly.

API Surface

Method	Endpoint	Description
POST	/ingest	Ingest local, Azure Blob, or AWS S3 content.
POST	/retrieve	Return contexts and sources without answer generation.
POST	/answer	Return or stream an LLM answer with contexts and sources.
GET	/files	List ingested documents.
DELETE	/files	Delete documents.
GET	/files/failed	List documents stuck in DocStatus.FAILED.
POST	/files/retry	Retry failed documents.
GET	/metadata/{doc_id}	Read document metadata.
POST	/metadata/{doc_id}	Merge or replace document metadata.
POST	/metadata/search	Find document IDs matching metadata filters.
GET	/images/{workspace}/{chunk_id}	Serve full or thumbnail visual chunk assets for source panels.
POST	/reset	Reset workspace storage.
GET	/workspaces	List registered workspaces and registry records.
POST	/workspaces	Create an empty workspace.
DELETE	/workspaces/{workspace}	Delete/reset one workspace.
GET	/health	Health and storage status.

All write endpoints accept optional workspace. Read endpoints accept workspaces for federated search. /answer streams by default; pass stream: false only when a single JSON response is required.

Development

git clone https://github.com/hanlianlu/dlightrag.git
cd dlightrag
cp .env.example .env
uv sync

CI (local)

make ci         # ruff, pyright, import-linter, unit tests (~2 min)
make ci-full    # + integration tests (needs PostgreSQL + pgvector)
make ci-e2e     # + E2E smoke tests (needs PG18 + AGE + API keys)

CI (GitHub Actions)

The badge above runs ruff → pyright → import-linter → unit tests → integration tests on every push and PR. E2E tests are workflow_dispatch only. Import boundary contracts are defined in pyproject.toml under [tool.importlinter].

Opt-in E2E smoke

docker compose -f docker-compose.yml -f docker-compose.e2e.yml up -d --build postgres
DLIGHTRAG_RUN_E2E_PG18=1 \
DLIGHTRAG_E2E_POSTGRES_PORT=55432 \
uv run pytest tests/e2e -m e2e_pg18 -q

The E2E smoke expects PostgreSQL 18 with pgvector, Apache AGE, and pg_textsearch installed, and age,pg_textsearch in shared_preload_libraries. It uses deterministic fake model functions by default, so it validates the storage/runtime path without external model API calls.

Useful References

• docs/response-schema.md - REST and SDK payloads.
• docs/retrieval_answer_mechanism.md - retrieval, filters, fusion, and answer generation.
• docs/database-role-architecture.md - primary/replica process roles.
• docs/module-layers.md - code organization and import boundaries.
• docs/PG.md - PostgreSQL requirements and tuning notes.

License

Apache License 2.0. See LICENSE.

Built by HanlianLyu. Contributions welcome.