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NORA

Your archive. Your assistant. Verifiable by anyone.

Meridian is a unified AI workspace for people who need to trust their own archive. Chat with every document you've ever kept, run deep research across your whole corpus, and ship answers that anyone can verify without trusting us.

5
Adversarial challenge stages
SHA-256
Content hash algorithm
Ed25519
Signature scheme
CC0
Specification license

How Meridian works.

  1. 01
    Ingest

    Connect your sources. Files are hashed on arrival and enter an append-only custody log.

  2. 02
    Enrich

    A local language model extracts typed claims per document — with explicit inference types and acknowledged gaps.

  3. 03
    Refute

    A five-stage adversarial harness challenges every claim before it's sealed into the archive.

  4. 04
    Answer

    You chat. Meridian retrieves, reasons, challenges, and emits a signed attestation with every response.

What's inside Meridian.

One workspace. Six capabilities. Every one of them emits and consumes Canon attestations, so no matter how you use Meridian, the result is checkable evidence — not opaque output.

Archive

Personal Data Archive

Ingest heterogeneous sources into one database with cryptographic content hashes and append-only chain of custody. Email, Drive, Dropbox, iCloud, disk, recordings, exports. Every document becomes a sealed ObservationAttestation on arrival.

Chat

Streaming chat with citations

Ask anything. Meridian searches your archive, retrieves relevant evidence, and answers with inline citations you can click through to the source. Built on the Vercel AI SDK for fast, streaming, model-agnostic conversations.

Research

Deep Research mode

For questions that require multi-step investigation. Meridian plans a strategy, runs iterative searches, cross-checks its own conclusions, and produces a synthesized BriefAttestation that binds every retrieved witness, every claim, and every challenge into one self-verifying chain.

Knowledge

Domain Packs

Plug-in knowledge bases curated by domain experts. Legal citation vocabularies. Medical terminology. Financial filings schemas. Journalism source categories. Bring your own, or use ours. Each pack extends the challenge vocabulary Meridian applies during refutation.

Integrations

MCP servers & APIs

Meridian speaks the Model Context Protocol. Connect any MCP server — GitHub, Linear, Gmail, calendar, databases, custom tools. Combine your archive with live data. Every tool call is recorded in the attestation chain.

Models

LLM Router

Use the right model for the job. Local models for privacy-sensitive work. Frontier cloud models for hard reasoning. Budget-tier models for bulk enrichment. Route by task, cost, latency, or privacy policy — Meridian handles the routing.

How Meridian compares.

Feature-by-feature against the tools you already know. We mark 'no' where we don't have a feature — honest accounting is the mandate.

FeatureMeridianChatGPT PlusNotion AIGleanWestlaw
Per-user database isolation
Each user gets a dedicated Postgres instance
YesNoNoNoPartial
Canon attestation on every answer
Ed25519-signed, falsifiable artifact
YesNoNoNoNo
Append-only custody chain
Merkle-linked audit trail for every operation
YesNoNoNoNo
Inline citations to source documents
Click-through to the specific paragraph
YesPartialNoYesYes
Deep research mode
Multi-step investigation with cross-checking
YesYesNoNoPartial
Sensitivity-tiered model routing
Local / sensitive / public routing per document
YesNoNoNoNo
Personal data archive
Ingest email, PDFs, recordings, exports
YesNoPartialYesNo
Knowledge base / workspace
Structured knowledge management
PartialNoYesYesYes
Real-time collaboration
Multi-user editing and commenting
NoNoYesPartialNo
Code generation
Write and execute code inline
NoYesNoNoNo
Open verification standard
Anyone can verify without vendor cooperation
YesNoNoNoNo
Legal-hold gating
Document-level preservation controls
YesNoNoNoYes
Comparison as of April 2026. Competitor features may change. Meridian acknowledges gaps honestly per Mandate §Honest Status.

Evidence-grade output, for everyone.

Most AI tools ship you a plausible paragraph. Meridian ships you a verifiable artifact. Every answer is a signed JSON attestation — a record of what was seen, what was concluded, what was challenged, and what was deliberately not examined.

What ships with every answer

  • A witness list — the retrieved documents, with content hashes
  • Typed claims — each with an inference type and supports
  • Applied challenges — what was cross-checked, what failed, what was declined
  • A cryptographic seal — Ed25519 signature over the canonical serialization

What anyone can do with it

  • Verify the signature — independently of Meridian or NORA
  • Re-hash every witness and confirm the retrieval was honest
  • Walk every claim back to its supports — no circular references, no orphan assertions
  • Review exactly what was not examined, and decide whether the scope is acceptable

This is the Canon standard. It's an open specification published by NORA Foundation under CC0 — Meridian is the reference implementation, but anyone can write a verifier, and anyone can build a conforming issuer. Read the Canon specification.

Technical specifications.

DatabasePostgreSQL 16 + pgvector
Signature schemeEd25519 (RFC 8032)
CanonicalizationRFC 8785 (JCS)
Content hashSHA-256
SearchBM25 + vector cosine + RRF
EmbeddingLocal-first, per-tenant
Target p95 latency< 1.5s (chat), < 30s (deep research)
Uptime target99.9% (GA)

One pipeline. Four tiers.

Witness is free forever. The paid tiers unlock personal archives, forensic features, and institutional isolation. Pricing reinforces posture — every tier enforces the mandate.

Witness
$0forever

Anyone curious about verifiable AI

  • Sample archive · read-only
  • Fast-tier model only
  • 50 sealed attestations / mo
  • Public /verify playground
  • Community support
Request access
Archivist
$24/mo

Individual knowledge work

  • 50 GB personal archive
  • All model tiers · $15 inf cap
  • All router profiles (incl. local)
  • Unlimited observation seals
  • Email support · 2 business days
  • Full data export
Start free trial
Forensic
$120/mo

Lawyers · journalists · researchers

  • 200 GB · $60 inf cap (tunable)
  • Deep-research · BriefAttestation
  • Legal-hold gating · priority ingest
  • Per-archive signing key
  • Cross-encoder rerank
  • Priority support · 1 business day
Start free trial
Institutional
Talkto us

Firms · newsrooms · compliance teams

  • Per-user Postgres isolation
  • SSO / SAML · BAA / DPA
  • Audit-export as deposition exhibit
  • On-prem option · dedicated bridge
  • Custom domain packs
  • Dedicated support · SLA
Book a call

Nonprofit & academic pricing · 50% off · Pro-bono attorneys free for 12 months on verification

Integrations
GmailSlackGoogle DriveNotionDropboxiCloud

Common questions.

A workspace built for the work that matters.

If your conclusions have to hold up under scrutiny, you need a tool that holds up under scrutiny. Meridian is that tool.