New — every answer now cites its sources
Built for teams drowning in docs

Turn messy documents into accurate answers in seconds

Lumen reads your PDFs, Notion pages, and Drive files, then answers questions with citations back to the exact paragraph. No more digging. No more guessing.

No credit card required · Free up to 200 pages

docs indexed daily
12k+
average rating
4.9/5
teams onboard
80+

Trusted by knowledge teams at

NorthbeamCortexaFernwoodAlloyPalisadeRunway HealthMercatoKeplerNorthbeamCortexaFernwoodAlloyPalisadeRunway HealthMercatoKepler
The problem

Documents keep multiplying.
Answers don't.

Companies generate knowledge faster than ever — then bury it in folders nobody can search. The cost isn't the storage. It's every decision made without the answer.

3.4 hrs

Lost to search every week

The average knowledge worker spends almost a full workday a week just looking for information that already exists inside the company.

9 versions

Of the same document

Drafts live in Drive, Notion, email attachments, and Slack. Nobody is sure which one is current — so they trust none of them.

62%

Of questions were asked before

Teams answer the same questions over and over in DMs and threads, because the answer isn't findable when it's needed.

Features

Everything you need to interrogate your documents

Six capabilities that turn a pile of files into a question-answering system your team can actually trust.

Ask any document

Query across PDFs, wikis, contracts, and meeting notes in plain English. No folder archaeology, no Ctrl+F marathons.

“What did we promise Acme in the March renewal?”

Source-backed answers

Every answer links back to the exact passage it came from. Verify a claim in one click instead of trusting a black box.

Cited: §4.2 — Security Whitepaper.pdf

Team knowledge base

Answers compound. When one person asks, the whole team benefits — and repeated questions trend toward zero.

42 questions answered this week · 0 repeats

Connect Drive, Notion, Slack

Sync the tools you already use. New documents are indexed automatically, so knowledge never goes stale.

Drive · Notion · Slack · +12 more connectors

Secure by default

Encryption at rest and in transit, per-workspace permissions, and audit logs your security team will actually approve.

SSO, SCIM, audit logs, EU data residency

API + embeddable chat

Ship a source-backed assistant into your own product with a few lines of code, or embed a chat widget anywhere.

POST /v1/ask { query, sources } → 200 OK

How it works

From scattered files to cited answers in three steps

No pipelines to build, no prompts to engineer. Connect your sources and start asking.

  1. 01

    Connect sources

    Link Google Drive, Notion, and Slack, or drop in PDFs. Setup takes two minutes and there is no pipeline to build.

  2. 02

    Index knowledge

    Lumen chunks, embeds, and deduplicates your documents — then keeps the index fresh as files change.

  3. 03

    Ask and cite

    Ask in plain language. Get a direct answer with citations to the exact source passage, ready to share.

Product preview

One workspace for every question

Files on the left. The answer in the middle. The evidence on the right. That's the whole product.

app.lumen.so — Northbeam workspace

What did we promise Acme about the renewal window?

Acme's renewal window is 60 days before the contract end date of Dec 31, 20251 — the account team committed to notifying them 90 days out, on Oct 22. Pricing hold of 8% was approved for a two-year term3.

3 sourcesAnswered in 1.2s12,431 chunks searched

Draft a two-line update for the account team.

“Hi team — Acme renewal opens Oct 2 (60-day window). An 8% pricing hold is approved if they sign a two-year term. I'll send the paperwork next week.”

Based on MSA §4.2 and renewal notes · edit before sending

Use cases

Built for the people who live in documents

Lumen is horizontal infrastructure, but it shines where answers must be fast and provable.

SaaS support teams

Answer tickets from internal docs in seconds — with the exact policy or help article attached.

  • 3× faster first response
  • Consistent macros with citations
  • Fewer escalations to engineering

Legal & ops

Find the clause without reading the whole contract. Every answer points to the paragraph.

  • Contract & policy lookup
  • Compliance evidence trails
  • Renewal obligation tracking

Sales enablement

Walk into every call with the answer — battlecards, pricing exceptions, security questionnaires.

  • Security questionnaire answers
  • Pricing exception history
  • Battlecards that stay current

Founders & internal docs

Your company's second brain. Onboarding, decisions, and postmortems — actually findable.

  • Day-one onboarding answers
  • Decision records in one place
  • “Why did we…” answered instantly
Testimonials

Teams stopped searching. They started asking.

Replace these with your own customers — the grid works with any number of quotes.

We used to have three people full-time just digging through contracts. Lumen answers the same questions in seconds — with the clause attached, so legal actually trusts it.
MOMaya OkaforHead of Operations · Northbeam
Our support queue dropped 40% in the first month. Reps paste the ticket in, get an answer with the exact help-center source, and move on. It's boring now — in the best way.
DRDaniel ReyesSupport Lead · Cortexa
I've bought a lot of AI tools that were demos wearing a suit. Lumen is the first one where the citations actually resolve to the right page. That's what made me keep it.
PRPriya RamanFounder · Fernwood Labs
Onboarding used to mean 'read 60 Notion pages, good luck.' Now new engineers ask Lumen on day one and ship by week one. Our ramp time halved.
TLTomás LaiferEngineering Manager · Alloy Systems
The security review was the shortest I've been through. Audit logs, EU residency, SSO — it was all just there. Procurement approved it in a week.
HWHannah WexlerCISO · Runway Health
I embedded the chat widget in our docs site in an afternoon. Customers now self-serve answers I'd have written manually 200 times this quarter.
JBJulian BakDevRel · Mercato
Pricing

Start free. Upgrade when the answers compound.

Every plan includes citations on every answer. No feature is paywalled behind 'contact us'.

MonthlyYearly2 months free

Starter

For trying Lumen on a small set of documents.

$0/ mo
  • 200 pages indexed
  • 100 answers / month
  • 1 workspace
  • File uploads (PDF, DOCX)
  • Community support
Most popular

Pro

For operators and teams that live in documents.

$29/ mo
  • 5,000 pages indexed
  • Unlimited answers
  • Drive, Notion & Slack sync
  • API + embeddable chat
  • Source citations on every answer
  • Email support

Team

For companies with security and scale requirements.

$79/ mo
  • Unlimited pages
  • Everything in Pro
  • SSO / SAML + SCIM
  • Audit logs & role-based access
  • EU data residency
  • Priority support

Cancel anytime. Switch plans whenever you like.

FAQ

Questions, answered — with sources

Everything buyers and users usually ask. Anything missing? The contact page is one click away.

Lumen is an AI document intelligence tool for teams. Connect your PDFs, Notion pages, Google Drive files, and Slack threads, then ask questions in plain English. Lumen returns direct answers with citations back to the exact source passage — so you can verify every claim.

Always. Every answer ships with numbered citations that link to the specific paragraph, page, or message it was drawn from. If a claim isn't supported by your documents, Lumen says so instead of guessing.

Yes — that's the whole point. Drag and drop PDFs and DOCX files, or connect Google Drive, Notion, and Slack for continuous sync. Lumen indexes your content and keeps the index fresh as files change.

Yes. The Pro plan includes a REST API (POST /v1/ask) and an embeddable chat widget, so you can build source-backed answers into your own product, internal tools, or docs site.

Starter is free forever and includes 200 indexed pages. Pro is $29/month (or $24 billed yearly) with 5,000 pages and unlimited answers. Team is $79/month with SSO, audit logs, and EU data residency. Yearly billing gives you two months free on every paid plan.

Yes. Lumen is built for commercial use — customer support, legal review, sales enablement, and internal operations. Output remains yours, and there are no restrictions on business use within your workspace.

No. Your documents are never used to train models. Data is encrypted at rest and in transit, processed only to answer your queries, and the Team plan adds EU data residency plus full audit logs.

This site is a Next.js + Tailwind template. All copy, pricing, features, and blog posts live in typed files under /src/lib. Brand colors are CSS variables in globals.css. See docs/customization.md for a 10-minute rebrand walkthrough.

Your documents already know. Start asking.

Join 80+ teams getting source-backed answers from their own knowledge. Free up to 200 pages — set up in two minutes.

No credit card required. We'll never share your email — privacy policy.