LightOn Python SDK

Seamlessly integrate state-of-the-art RAG directly into your software.

What is LightOn?

LightOn is a 🇪🇺 European AI lab building industrial-grade retrieval infrastructure: index your documents, then query them with grounded ask and search actions, and process documents on the fly with parse and extract for specific, standalone actions. This SDK wraps the LightOn API. Create an account and get an API key on console.lighton.ai 🚀

Note from the human maintainers:

This code-base is implemented with AI assistance to allow our team to keep up with the required development celerity, however be assured that all design-patterns, architectural decisions, code-reviews and QA cycles are fully human-backed to ensure that this SDK meet our standards of quality and that we maintainers keep full knowledge of its inner workings to better serve the developer community <3

Quick start

Install:

uv add lighton-sdk

Set your API key in your environment:

export LIGHTON_API_KEY="..."

Get your first result:

from lighton import LightOn, Workspace

with LightOn() as client:  # reads LIGHTON_API_KEY from the environment
    # Create a workspace and ingest a folder of PDFs (glob), blocking until searchable
    ws = Workspace(name="Docs").create(client)
    ws.ingest_many(["docs/**/*.pdf"], wait=True)

    # Search: retrieve the most relevant passages, scoped to that workspace
    chunks = client.search("Q4 revenues", workspaces=[ws])
    for r in chunks.results:
        print(r.score, r.source.filename, r.content)

    # Single-turn RAG for simple use-cases, using an LLM registered on your account
    answer = client.ask(
        "What were Q4 revenues?", workspaces=[ws], model="mistral-large-latest"
    )
    print(answer.answer)

Ingestion

Get documents in first: ask/search only see files ingested into a workspace. Upload one file with Workspace.ingest(), or many at once with ingest_many(). Uploading is the ingestion; a File carries a processing status you can poll.

from lighton import ExecMode, File, LightOn, Workspace

with LightOn() as client:
    ws = Workspace.get(client, 42)

    # One file, non-blocking (returns immediately, status "pending")
    f = ws.ingest(File(path="report.pdf"))
    ws.ingest(File(path="report.pdf"), wait=True)   # or block until embedded

ingest_many() takes paths, Files, and glob patterns (mixed). Every path is validated before any upload; it returns a BatchIngest with succeeded / failed:

batch = ws.ingest_many(
    ["contracts/*.pdf", "reports/**/*.docx", File(path="extra.pdf")],
    wait=True,             # wait for each to finish embedding
    ignore_errors=True,    # collect failures instead of raising on the first
)
print(len(batch.succeeded), "ok,", len(batch.failed), "failed")
for fail in batch.failed:
    print(fail.source, "→", fail.error)

The client paces every request (uploads and status polls) to stay under a per-minute cap and applies the 429 cooldown automatically. It defaults to 1000 requests/minute, the API's limit for most endpoints, so batches stay within bounds out of the box. Override it if your account differs (or pass None to disable pacing):

from lighton import LightOnConfiguration

# override the default cap (or pass None to disable pacing)
with LightOn(config=LightOnConfiguration(max_requests_per_minute=2000)) as client:
    Workspace.get(client, 42).ingest_many(["docs/**/*.pdf"])

Run it in the background with mode=ExecMode.ASYNC and poll the job's progress:

import time

from lighton import BatchIngest, BatchProgress

with LightOn() as client:
    ws = Workspace.get(client, 42)
    job = ws.ingest_many(["docs/**/*.pdf"], wait=True, mode=ExecMode.ASYNC)

    while not job.done:
        p: BatchProgress = job.poll()
        print(f"{p.uploaded}/{p.total} uploaded, {p.ingested} embedded, {p.failed} failed")
        time.sleep(2)

    result: BatchIngest = job.wait()   # once finished

More on file management (list, fetch, tags, delete) and polling in Files & ingestion and Async jobs & polling.

Primary verbs

Four actions live directly on the client. ask and search query your indexed documents, scope them with workspaces=, tags=, or files= (objects or bare ids). parse and extract process a document on the fly, no indexing required. Full reference at developers.lighton.ai. The per-verb snippets below assume a client opened with with LightOn() as client:.

`ask`: single-turn RAG

Retrieval-augmented generation: retrieves the most relevant chunks and has an LLM answer your question grounded in them, returning the answer plus the sources it used. Reach for it when you want a direct answer over a corpus. Choose the answering model with model= (any LLM registered on your account).

resp = client.ask(
    "What were Q4 revenues?",
    workspaces=[42],
    max_results=5,
    model="mistral-large-latest",
)
print(resp.answer)
for r in resp.results:          # the chunks used as grounding
    print(r.source.filename, r.score)

`search`: retrieval only, no generation

Hybrid semantic + lexical retrieval that returns ranked chunks with scores, source metadata, and (optionally) page images, but no generated answer. Use it to feed context into your own pipeline/LLM, build custom ranking, or surface sources to users.

from lighton import RelevanceScoring, SearchMode

resp = client.search(
    "termination clause",
    tags=[7],
    mode=SearchMode.text,        # .text (hybrid) or .vision (page-image)
    include_image=True,          # attach a base64 page image per chunk
)
for r in resp.results:
    print(r.score, r.content)

relevance_scoring tunes the scoring step (applies to ask too):

.scoring_and_filtering (default): score, drop chunks below the quality threshold
.scoring_only: score every candidate, return them all
.none: skip scoring; lowest latency, r.scores.relevance is None

`parse`: document → Markdown

One-off conversion of a PDF, Office file, or image into structured per-page Markdown, without storing it in your index. Ideal for feeding documents into another tool. Pass a local path or a public url (exactly one).

doc = client.parse(path="report.pdf")
# doc = client.parse(url="https://example.com/report.pdf")
for page in doc.result.pages:
    print(page.index, page.markdown)

Large documents can time out synchronously, run them async and poll (see Async jobs & polling): client.parse(path="big.pdf", mode=ExecMode.ASYNC).

`extract`: schema-guided structured data

Pull specific, typed fields out of a document for a custom pipeline: you describe the shape (a pydantic model or a raw JSON Schema) and get back data matching it, one object per page. See Extract below for the full schema guide.

resp = client.extract(schema=InvoiceModel, path="invoice.pdf")
print(resp.result.data)

Workspaces

Workspaces are the containers your documents live in, retrieval scopes to them. They're active-record objects: an instance manages its own lifecycle.

from lighton import LightOn, Workspace

with LightOn() as client:
    # Create
    ws = Workspace(name="Legal", description="Contracts & NDAs").create(client)

    # Edit, then persist
    ws.name = "Legal EU"
    ws.save()

    # Re-fetch from the API
    ws.refresh()

    # List (follows pagination) and retrieve by id
    for w in Workspace.list(client):
        print(w.id, w.name)

    ws = Workspace.get(client, ws.id)

    # Delete
    ws.delete()

Files & ingestion

Uploading a file into a workspace is the ingestion, there's no separate job to track. The returned File carries a processing status; poll it with refresh(), or wait() to block until it's embedded. Ingestion is non-blocking by default.

from lighton import LightOn, Workspace, File, wait_all

with LightOn() as client:
    ws = Workspace.get(client, 42)

    # Upload, returns immediately, f.status == "pending"
    f = ws.ingest(File(path="report.pdf"))

    f.refresh()          # poll status whenever you like
    print(f.status)      # pending → parsing → embedding → embedded

    # Or block until ready (opt-in)
    ws.ingest(File(path="report.pdf"), wait=True)

    # Bulk upload, then wait on all concurrently (threads, the SDK is sync)
    files = [ws.ingest(File(path=p)) for p in ("a.pdf", "b.pdf", "c.pdf")]
    wait_all(files)

    # Manage existing files (active-record, like Workspace/ApiKey)
    for doc in File.list(client, workspace_id=42):
        print(doc.id, doc.filename, doc.status)

    doc = File.get(client, f.id)

    # Or fetch by name within a workspace — matches the title, so pass the name you
    # uploaded (the server uniquifies the stored filename). The extension is optional.
    # Returns every match (titles aren't unique), empty if there are none.
    # workspace takes a Workspace or an id.
    docs = File.get_by_name(client, "report.pdf", workspace=42)
    doc = docs[0]
    doc.title = "Q4 Report"
    doc.save()

    # Assign / remove tags, by Tag object, id, or name (see Tags below)
    doc.tag([7, "contracts"])
    doc.untag([12])

    doc.delete()

Once a file reaches embedded, it's retrievable by ask/search.

Async jobs & polling

Two things in the SDK are asynchronous and polled: ingestion (a File's status, via refresh() / wait() shown above) and parse / extract run in async mode, which return a job handle you poll. Same idea in both, kick off the work, poll until it reaches a terminal state.

parse and extract take mode= (an ExecMode, default ExecMode.SYNC). Pass ExecMode.ASYNC to queue the job, the call returns a ParseJob / ExtractJob handle instead of blocking. Call job.poll() to refresh it in place; job.succeeded is the one success state and job.done means terminal (finished either way). Handy for large documents that would otherwise time out.

import time

# queue the job, returns right away, job.status == "pending"
job = client.extract(schema=Letter, path="big-scan.pdf", mode=ExecMode.ASYNC)

while not job.poll().succeeded:
    if job.done:                                # terminal but not completed → failure
        raise RuntimeError(f"extract job {job.id} ended as {job.status!r}")
    if job.progress:                            # optional live progress
        print(f"{job.progress.percentage}% ({job.progress.pages_processed} pages)")
    time.sleep(2)

for row in job.result.data:
    print(row)

poll() mutates the job and returns it, so while not job.poll().succeeded: reads naturally; raising once job.done (terminal but not successful) means a stuck or failed job surfaces instead of looping forever.

parse is the same shape, on failure a ParseJob carries an error block you can raise with directly:

import time

job = client.parse(path="big.pdf", mode=ExecMode.ASYNC)

while not job.poll().succeeded:
    if job.error is not None:                   # terminal failure
        raise RuntimeError(f"parse job {job.id} failed: {job.error.message}")
    time.sleep(2)

for page in job.result.pages:
    print(page.index, page.markdown)

Extract

extract(schema, *, path | url) pulls structured data from a document, pass a local path to upload (multipart) or a public url to fetch, exactly one (same as parse). The schema drives guided generation and can be a pydantic model or a raw JSON-Schema dict, use whichever you have.

A pydantic model is the easy path: nested models, list[...], and X | None fields all convert to a valid vLLM response_format schema for you.

Give every field a meaningful Field(description=...), the descriptions are carried into the schema and steer the model, so they materially improve extraction quality. Treat them as instructions, not documentation.

from lighton import LightOn
from pydantic import BaseModel, Field


class Person(BaseModel):
    last_name: str = Field(description="Family name, as written in the document.")
    first_name: str | None = Field(
        None, description="Given name; null if not stated."
    )
    role: str | None = Field(
        None, description="Title or role if given, e.g. 'sender', 'recipient'."
    )


class Letter(BaseModel):
    people: list[Person] = Field(
        description="Every person or entity named in the letter."
    )
    subject: str | None = Field(
        None, description="The letter's stated subject line, or null if absent."
    )


with LightOn() as client:
    resp = client.extract(schema=Letter, path="letter.pdf")
    # or from a public URL: client.extract(schema=Letter, url="https://example.com/letter.pdf")
    for row in resp.result.data:          # one object per page
        print(row)

Or pass the schema dict directly, it's validated against the JSON-Schema meta-schema (raises jsonschema.SchemaError if malformed) and sent as-is:

with LightOn() as client:
    resp = client.extract(
        url="https://example.com/invoice.pdf",
        schema={
            "$schema": "https://json-schema.org/draft/2020-12/schema",
            "type": "object",
            "properties": {
                "total": {"type": "number"},
                "currency": {"type": ["string", "null"]},
            },
            "required": ["total"],
        },
    )
    print(resp.result.data)

Need the converted schema without calling the API (to inspect or cache it)?

from lighton.utils import convert_pydantic_to_response_format_json

schema = convert_pydantic_to_response_format_json(Letter)

Content types

Content types are a company-wide taxonomy (legal:contract:nda, …) with typed attributes. Browse it with ContentType.list(), it returns a tree (each node has children, and attributes when include_attributes=True):

from lighton import ContentType

for ct in ContentType.list(client, include_attributes=True):
    print(ct.path, ct.label)
    for attr in ct.attributes:
        print("  ", attr.name, attr.type, attr.choices)

Classify a file (assign a content type) and set its attribute values. classify, unclassify, set_attribute, and clear_attribute all take a ContentType object or a plain path string:

from lighton import File

doc = File.get_by_name(client, "nda-2026.pdf", workspace=42)[0]

doc.classify("legal:contract:nda")
doc.set_attribute("legal:contract:nda", "jurisdiction", "FR")
doc.set_attribute("legal:contract:nda", "signed_on", "2026-07-01")  # date → "YYYY-MM-DD"

# Inspect what's assigned (a Facet per content type, with attribute values)
for facet in doc.facets():
    print(facet.path, {a.name: a.value for a in facet.attributes})

doc.clear_attribute("legal:contract:nda", "jurisdiction")
doc.unclassify("legal:contract:nda")

API keys

Same active-record style. The plaintext secret is available only right after create().

from lighton import LightOn, ApiKey, ApiKeyScope, Role

with LightOn() as client:
    key = ApiKey(
        name="ci-pipeline",
        scopes=[ApiKeyScope(workspace_id=42, role=Role.viewer)],  # omit for an unscoped key
    ).create(client)

    print(key.key.get_secret_value())  # plaintext secret (SecretStr), shown once, store it now

    # Manage existing keys
    for k in ApiKey.list(client):
        print(k.id, k.name, k.prefix)

    key = ApiKey.get(client, key.id)
    key.name = "ci-pipeline-v2"
    key.save()
    key.delete()

Client configuration

LightOn() with no arguments reads LIGHTON_API_KEY from the environment and talks to https://api.lighton.ai. To point it somewhere else — a self-hosted deployment, a staging environment, a local instance — pass a base_url:

from lighton import LightOn, LightOnConfiguration

with LightOn(
    api_key="sk-...",  # or omit and let it read LIGHTON_API_KEY
    config=LightOnConfiguration(base_url="https://lighton.internal.acme.com"),
) as client:
    print(client.search("onboarding policy").results)

base_url is the host only: the SDK appends the /api/v3/... paths itself, and a trailing slash is stripped, so https://host/ and https://host behave the same.

Everything on LightOnConfiguration is optional and independent, override only what you need:

field	default	what it controls
`base_url`	`https://api.lighton.ai`	API root; point at another deployment
`timeout`	5 s connect, 120 s read	`httpx.Timeout`; raise the read timeout for slow parses
`retries`	`3`	connection-level retries with backoff (httpx transport), not HTTP errors
`max_requests_per_minute`	`1000`	paces every request under the API cap; `None` disables pacing
`rate_limit_retries`	`3`	retries on HTTP 429, waiting `Retry-After` when present; `0` disables
`transport`	`None`	a custom `httpx.BaseTransport`, for a proxy, or `MockTransport` in tests

The API key stays a direct LightOn() argument rather than a config field, so a config object can be shared or logged without carrying a secret.

A local instance over plain HTTP, with a longer read timeout and no pacing:

import httpx

config = LightOnConfiguration(
    base_url="http://localhost:8000",
    timeout=httpx.Timeout(600.0, connect=5.0),
    max_requests_per_minute=None,
)
with LightOn(config=config) as client:
    ...

Agent Frameworks

LightOn drops into any agent framework as a retrieval tool: wrap a client.search() call that returns text the LLM can read, and hand it to your agent. (Swap search for ask if you'd rather the tool return a grounded answer than raw chunks.)

The snippets assume a client (see Quick start), in a long-running agent, open it once for the process lifetime. They share this helper, which searches a workspace and formats the hits into a string:

def lighton_search(query: str) -> str:
    """Search the company's document corpus for passages relevant to the query."""
    resp = client.search(query, workspaces=[42], max_results=5)
    return "\n\n".join(f"[{r.source.filename}] {r.content}" for r in resp.results)

LangChain

# pip install langchain-core
from langchain_core.tools import tool

lighton_tool = tool(lighton_search)          # name + description come from the function
# bind it: llm.bind_tools([lighton_tool]), or pass to create_react_agent(...)

LangGraph

Reuses the LangChain lighton_tool above, pass it to a prebuilt ReAct agent:

# pip install langgraph
from langgraph.prebuilt import create_react_agent

agent = create_react_agent(model="openai:gpt-5", tools=[lighton_tool])
result = agent.invoke({"messages": [{"role": "user", "content": "What were Q4 revenues?"}]})

LlamaIndex

# pip install llama-index-core
from llama_index.core.tools import FunctionTool

lighton_tool = FunctionTool.from_defaults(fn=lighton_search)
# agent = ReActAgent.from_tools([lighton_tool], llm=...)

OpenAI Agents SDK

# pip install openai-agents
from agents import Agent, function_tool

agent = Agent(name="Search", tools=[function_tool(lighton_search)])

CrewAI

# pip install crewai
from crewai.tools import tool

lighton_tool = tool("lighton_search")(lighton_search)
# pass tools=[lighton_tool] to your crewai Agent

Name		Name	Last commit message	Last commit date
Latest commit History 61 Commits
.github/workflows		.github/workflows
lighton		lighton
tests		tests
.gitignore		.gitignore
.pre-commit-config.yaml		.pre-commit-config.yaml
AGENTS.md		AGENTS.md
CLAUDE.md		CLAUDE.md
CONTRIBUTING.md		CONTRIBUTING.md
LICENSE		LICENSE
Makefile		Makefile
README.md		README.md
cliff.toml		cliff.toml
pyproject.toml		pyproject.toml
uv.lock		uv.lock

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LightOn Python SDK

What is LightOn?

Contents

Quick start

Ingestion

Primary verbs

`ask`: single-turn RAG

`search`: retrieval only, no generation

`parse`: document → Markdown

`extract`: schema-guided structured data

Workspaces

Files & ingestion

Async jobs & polling

Extract

Tags

Content types

API keys

Client configuration

Agent Frameworks

LangChain

LangGraph

LlamaIndex

OpenAI Agents SDK

CrewAI

About

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Repository files navigation

LightOn Python SDK

What is LightOn?

Contents

Quick start

Ingestion

Primary verbs

ask: single-turn RAG

search: retrieval only, no generation

parse: document → Markdown

extract: schema-guided structured data

Workspaces

Files & ingestion

Async jobs & polling

Extract

Tags

Content types

API keys

Client configuration

Agent Frameworks

LangChain

LangGraph

LlamaIndex

OpenAI Agents SDK

CrewAI

About

Topics

Resources

Contributing

Stars

Watchers

Forks

Releases

Contributors

Languages

`ask`: single-turn RAG

`search`: retrieval only, no generation

`parse`: document → Markdown

`extract`: schema-guided structured data