One layer. Two ways to get it.
GraphRAG is the application, sold and scoped with your team. Perseus is the platform, free to start.
GaphRAG
Perseus
No seat fees. No per-query meters.
Start here
Pilot Program
Scoped
Proven value on one use case in 8–12 weeks
Everything in Production Deployment
Embedded ontologists
Graph engineering hours
Quarterly ontology refresh
On-prem and air-gapped available
Design your pilot
Recommended
Get production ready
Production Deployment
Scoped
Production deployments across the organization
Multiple workspaces & ontologies
Custom document ingestion
Cloud or VPC deployment
SSO, SAML, audit logs, SIEM export
99.9% uptime SLA, dedicated CSM
Scope your deployment
For complex domains
In-house Experts
Scoped
Embedded ontologists for fast-evolving or regulated domains
Everything in Production Deployment
Embedded ontologists
Graph engineering hours
Quarterly ontology refresh
On-prem and air-gapped available
Talk to an expert
Developer
Free
Ideal for individuals and small projects
Graph & Ontology Building
Ontology Editor & Evaluation
30 KB max input size
5 Graph builds / 30 days
1 Ontology build / 30 days
Community support
Start for free
Recommended
Plus
Pay-per-use
0.01$ per PCU
Ideal for small teams and growing projects
Graph & Ontology Building
Ontology Editor & Evaluation
1MB max input size
3000 Graph builds / 30 days
300 Ontology builds / 30 days
Email support
Get Started
Enterprise
Custom
Custom solutions for large organizations
Graph & Ontology Building
Ontology Editor & Evaluation
Unlimited input sizes
Unlimited Graph & Ontology builds
Dedicated support
99.99% uptime SLA
Contact Sales
Comparaison table
Frequently Asked Questions
Yes, this is how most of our customers start. Pilot terms convert into Enterprise agreements with pilot fees credited against the first year's license. No rebuild of your ontology or workspace is required.
VPC is available on Enterprise. On-prem and air-gapped deployments are available on Enterprise + Expert Services, including for sovereign-cloud requirements. Our team handles installation and lifecycle, you do not need in-house graph-database expertise.
Annual invoicing against a PO by default. Multi-year agreements and custom billing cycles are supported on Enterprise. On the + Services tier, platform license and services hours are billed as separate line items so services procurement can approve them independently.
Perseus is the graph infrastructure layer underneath Lettria. You do not interact with it directly on the Lettria platform, but its reliability is the reason Lettria's accuracy and explainability hold up in production. If your platform team also wants SDK-level access to build custom knowledge graphs, see Perseus ↗.
SOC 2 Type II, GDPR (with DPA), and ISO 27001. HIPAA-ready configuration and EU AI Act-aligned controls are available on Enterprise and above. Full compliance documentation including pen-test summaries is available under NDA on the Security and trust page ↗.
A typical engagement opens with a two-week ontology sprint, followed by graph build over 6 to 12 weeks, then ongoing refresh cycles. Our ontologists work embedded with your subject-matter experts, not at arm's length, and transfer knowledge as they go so you are not locked in.
Documents and derived graph data are retained for the duration of your contract and deleted within 30 days on request or on termination. Audit-log retention is configurable on Enterprise to match your internal compliance window.
Data is stored in the region you select (EU, US, or custom for Enterprise) and never leaves it. Your documents, your ontology, and your queries are never used to train our models or any third-party model. Our DPA contains the full commitment in writing.
Turn complex enterprise knowledge into reliable AI
Choose the path that fits your team: explore Knowledge Studio or start building with Perseus.
