Security boundaries

Name the control. Name the limit.

Substrate documents specific boundaries instead of making an unqualified security, privacy, or compliance claim.

Review the controls

Implemented boundaries

Controls around published memory.

Effectiveness still depends on correct configuration, operations, providers, and customer behavior.

Tenant isolation

Each account is one tenant. Data lives in Azure Database for PostgreSQL in shared tables where every row carries the tenant and row-level security is enforced by the database. The application role cannot bypass it.

Immutable sources

Raw sources and captured events are written to Azure Blob Storage under the tenant’s own prefix and never rewritten. An append-only, hash-chained manifest records their order.

Sign-in and billing

Clerk handles sign-in and account deletion webhooks. Stripe handles subscriptions. Substrate stores no card details.

Read-only connectors

Notion access uses a read-only integration you approve page by page. Gmail access is read-only through Composio-managed OAuth; Substrate stores only an encrypted routing reference, never your Google tokens. Substrate never writes to Notion or Gmail.

Agent access

Each agent connection is approved by you in the browser and can be revoked in Authorized Agents. Agent keys are stored hashed. An agent sees only your tenant and the branches shared with you.

Sharing boundary

A share exposes exactly what the shared pages rendered, enforced in the query and again by row-level security. Every share-scoped read is logged in your ledger. Raw files are excluded unless you include them.

What is not claimed

No control is absolute.

No blanket assurance

No general “secure,” “private,” “enterprise-ready,” or compliance claim is made. No certification is represented here.

Backups and providers

Deletion from every backup and downstream provider may not be immediate. Applicable retention is stated in the Privacy Notice and customer terms.

Providers and regions.

Data is processed in Microsoft Azure (United States). Model inference for extraction and page generation uses ChatGPT Luna. No certification is represented.

Questions