Private AI for legal professionals

Inference on your hardware. Index on your server.
ContextSage has no access to any of it.

Attorney-client privilege enforced by architecture, not a privacy policy.

Open app — it's free See pricing

What practitioners who've built this at scale say

RAG for legal is harder than it looks.

Engineers who've built RAG for the Air Force, hedge funds, and 25-million-document corpora say the same things. We listened and built accordingly.

"You'll spend a LOT of time on chunk size, overlap, top K, ranking, and reranking. You won't get this right on the 1st go — or the 10th."

ContextSage ships a legal-tuned retrieval pipeline. Cross-encoder reranking trained on 500+ CUAD contracts. No tuning required.

"The #1 requirement is to have it on site. No data leaves the firm."

Inference runs in your browser tab via WebGPU. Your documents never touch our servers. Subpoena us — we have nothing.

"Sometimes when I ask about a certain customer, it can't find the chunks that are about this specific person."

Per-matter isolation + entity-aware reranking surface the right document, not a plausible-sounding one from a different case.

"85% of their data is in a pretty crappy state — especially the metadata."

Aspose-powered OCR and DocumentProcessor normalize scanned PDFs, remove running headers, and clean metadata on ingest.

"RAG quality needs to be nurtured. Bad data causes hallucinations and confusion."

Policy engine enforces grounding before the answer renders. If no chunk covers the question, the model says so — it doesn't invent.

"Security is consistently pushed to the bottom of the list… later never comes around."

Zero-trust by default. Per-matter isolation, PHI gatekeeper, and hallucination audit log ship on day one — not after launch.

Custom RAG builds for a single law firm run $25k–$72k plus $1–2k/month maintenance. ContextSage ships the same architecture, pre-tuned for legal, for a fraction of that.

Built for professionals who can't afford a data breach

Runs on your device

WebLLM uses your GPU via WebAssembly. Inference happens in the browser tab. Nothing is sent to ContextSage servers.

Bring your own hardware

Connect a local Ollama instance, a VPS, or a RunPod GPU pod. Pro runs a personal bridge. Teams share a firm bridge. You own the server.

Zero data custody

We hold no client data — not encrypted on our servers, not on our servers at all. Subpoena us and we have nothing to hand over.

Workspace isolation

Documents, searches, and conversation history are siloed per matter. No cross-matter bleed. Call it a matter, a patient file, a study — your call.

Index compounds with use

Every document you ingest becomes part of your practice. Depositions, contracts, case notes — all searchable. The index grows with your work.

PHI gatekeeper

Every prompt is inspected before any cloud call. Sensitive content stays local or is redacted before leaving your network.

Services stay connected

Google Drive, Gmail, OneDrive and more reconnect automatically. Silent token refresh — no re-auth interruptions mid-work.

Sources answers before writing them

When RAG mode is on, the model identifies which passages are relevant and assesses whether they cover the question before drafting an answer. Gaps in your documents are acknowledged — not filled from training knowledge.

Team / Enterprise

Shared workspace

The whole team queries the same index on your firm's server. One bridge, shared across devices, built on hardware you control.

Pro

Citation verification

A policy engine validates every [source] citation against the actual retrieved chunk before the answer renders. Fabricated or mismatched citations are flagged automatically — not caught after the fact.

Pro

Hallucination audit log

Every time the model answers from training data instead of your documents, or cites a passage it never saw, the query and response are written to an inspector queue. Compliance has a timestamped record.

Enterprise

Clause coverage report

Before you ask a question, know what the document contains. Every ingested contract is scanned for 136 clause types. High-confidence finds, uncertain matches, and absent provisions are surfaced in a structured report — not buried in an answer.

Enterprise

Domain-specific clause tuning

Standard clause models are trained on generic corpora. Your M&A practice, your IP portfolio, your outsourcing agreements have their own language. We tune the retrieval model to your firm's document corpus — so the system finds the clauses your attorneys actually look for.

Why the trust model is structural, not contractual

Most AI tools ask you to trust their privacy policy. ContextSage removes the need for trust entirely.

Technical

Your hardware, full stop

WebLLM runs inference in your browser using your GPU. The Bridge connects your local Ollama or a RunPod pod you spin up and control. ContextSage has no compute cluster. Your documents never transit our servers — there is no route for them to take.

Trust

Nothing to subpoena

Attorney-client privilege is not a feature you configure. It is enforced by the fact that we hold no client data. Not encrypted on our servers. Not on our servers at all. A court order directed at us would produce nothing because we have nothing.

Switching cost

The index is yours

Every deposition, contract, and case note you ingest becomes part of your practice's index. That index grows with your work. Switching to another tool means re-ingesting everything — months of work product, rebuilt from scratch. That cost is a feature, not a trap: it means your index is genuinely valuable.

Pro

The answer is either sourced or it doesn't appear

Every other AI tool asks the model to behave. ContextSage enforces it at the pipeline level. A policy engine sits between your documents and the LLM — validating retrieval, enforcing citations, and logging every deviation before anything reaches your screen.

Verification

Every claim is traced to a chunk

When the AI cites a document, a finite state machine verifies that citation against the actual retrieved passage before the answer reaches your screen. Invented source? Flagged. Wrong page? Flagged. The model cannot fabricate a citation and have it pass silently.

Abstention

Silence beats a confident wrong answer

If nothing in your uploaded documents answers the question, the system says so. Not a guess from training data dressed up as a finding. The retrieval pipeline knows the difference between "not in this document" and "not in any document" and routes each correctly.

Audit trail

Every violation is logged

Every time the model tries to answer from training knowledge instead of your documents — or cites a passage that was never retrieved — the query, the response, and the retrieved chunks are written to an inspector queue. Compliance has a record. Nothing is silent.

Adaptation

Retrieval strategy evolves with your firm

The policy engine tracks which retrieval strategies succeed on your firm's document corpus. When accuracy degrades or new patterns emerge, it designs a candidate policy, tests it quietly against 10% of live traffic, and promotes it only if it outperforms the incumbent. Your index gets smarter without you touching configuration.

Why this matters for regulated industries. A hallucinated citation in a brief is a malpractice exposure. A wrong drug interaction sourced to training data is a patient safety risk. The policy engine does not reduce hallucination rates — it makes hallucinations detectable, logged, and structurally harder to produce in the first place.

Pro — why it's different

Prompting is a request.
This is enforcement.

Every RAG tool on the market gives the model instructions: cite your sources, say you don't know when you're unsure, stay grounded in the documents. The model may or may not comply. If it doesn't, you find out when a lawyer cites a hallucinated case.

Prompt-only approach ContextSage
System prompt says "only use the provided context" FSMGuard retrieves content, then validates every citation against the actual retrieved chunks after the response is generated — not before
"I Don't Know" exit phrase written into the system prompt Detection fires when the model was instructed to abstain but gave a substantive answer anyway — catches non-compliance regardless of what the model chose to do
No visibility when the model ignores its instructions Every violation written to an audit log with the query, the full response, the retrieved content, and the flag reason
Static prompt — no improvement when it fails Violation scores feed the policy engine. Policies that produce fewer violations automatically replace ones that don't

The model can ignore a system prompt.
It cannot ignore the validator.

Simple pricing

Free

$0 / forever
Open app
  • WebLLM browser inference
  • IndexedDB vector search
  • BYOK cloud API keys
  • Matter isolation
  • MCP connectors (Google Drive, Gmail, Calendar, Sheets)
  • Persistent service sessions — auto-renews, no re-auth
  • Manual import to RAG
  • RAG grounded mode — answers sourced from your documents by default
Most popular

Pro

$XX / per month
Get Pro
  • Everything in Free
  • Bridge — local Ollama or remote GPU (bring your own hardware)
  • RunPod GPU inference via Bridge
  • Persistent sqlite-vec vector store (OPFS, no bridge needed)
  • Bridge sqlite-vec (server-side, fastest ANN)
  • Pro embedding models (BGE Large, Nomic, mxbai)
  • Notion, Slack, OneDrive, Dropbox, Linear, Jira connectors
  • Subscription management via Stripe portal
  • RAG policy engine — citation enforcement on every response
  • Hallucination audit log (inspector queue)
  • Adaptive retrieval — policy evolves to your document corpus

Enterprise

Contact us
Talk to us
  • Everything in Pro
  • HIPAA / SOC 2 compliance layer
  • RBAC (admin, attorney, paralegal)
  • Tamper-evident audit log
  • Air-gapped deployment option
  • Amazon Bedrock cloud fallback
  • Clause coverage report — per-document inventory of found, uncertain, and absent provisions
  • Domain-specific clause tuning — retrieval model trained on your firm's practice area
  • Custom clause definition library — add proprietary clause types beyond the standard 136
  • SLA + dedicated support