Your API Data Belongs on Your Machine, Not Someone Else's Cloud
RESTK is built with a privacy-first, security-hardened architecture. Local storage by default, AES-256 encryption at rest, optional E2E encrypted cloud sync, OS keychain integration, RBAC, and complete audit logging. Built for teams that take security seriously.
Privacy by Architecture, Not by Policy
Most API tools promise privacy in their terms of service. RESTK enforces it through architecture. When your data never leaves your machine, there is nothing to breach.
Local-First Storage
All your API data — collections, environments, request history, test scripts — is stored in a local database on your machine. Nothing is sent to external servers by default. You own your data completely.
Encrypted at Rest
Your local database is encrypted using AES-256 encryption. Encryption keys are stored in your operating system keychain (macOS Keychain, Windows Credential Manager, or Linux Secret Service), never in plain text on disk.
Optional Cloud Sync
When you choose to sync, all data is end-to-end encrypted before leaving your machine. RESTK servers cannot read your workspace data. You select exactly what syncs — secrets can always stay local.
GDPR Compliant
RESTK is designed for GDPR compliance by architecture. We collect minimal telemetry (which you can disable), support data export and deletion requests, and store data in regions you specify for cloud sync.
The critical distinction is between privacy by policy and privacy by architecture. A cloud-first tool can promise not to read your data, but the data still sits on their servers. A breach, a subpoena, a change in terms of service, or an employee with the wrong access level can expose everything. When data does not exist on external servers, none of these risks apply.
RESTK's privacy model is simple: your data is on your machine by default. If you choose to enable cloud sync, the data is encrypted on your machine before transmission. The encryption key never leaves your device. RESTK's servers store encrypted blobs that are meaningless without your local key. This is not a marketing claim — it is a mathematical guarantee enforced by cryptography.
Security That Goes Beyond the Basics
Real security is not a feature checkbox. It is a comprehensive approach to protecting every layer of your API workflow.
End-to-End Encryption
All data that leaves your machine is encrypted using your workspace encryption key before transmission. This is true end-to-end encryption — not server-side encryption where the provider holds the keys. Even if RESTK servers were compromised, your data remains unreadable without your local encryption key.
OS Keychain Integration
Sensitive values like API keys, OAuth tokens, bearer tokens, and environment secrets are stored in your operating system's native secure storage. On macOS, this is Keychain. On Windows, the Credential Manager. On Linux, the Secret Service API. These are the same systems your OS uses to protect its own credentials.
Role-Based Access Control
For teams using cloud sync, RESTK provides granular role-based access control. Define who can view, edit, execute, or administer specific collections and environments. Prevent junior developers from accessing production credentials while giving them full access to development workspaces.
Audit Logging
Every meaningful action in a team workspace is logged: who created a request, who modified an environment variable, who executed a request against production, who changed permissions. Audit logs are tamper-resistant and exportable for compliance reporting.
How RESTK Handles Sensitive Data
API testing inherently involves working with sensitive data. Authentication tokens, API keys, OAuth credentials, webhook secrets, and sometimes even personally identifiable information in request or response payloads. How your API tool handles this data is not a minor detail — it is a fundamental security concern.
RESTK classifies data into two categories: workspace data (collections, requests, folder structure, test scripts) and secrets (API keys, tokens, passwords, certificates). These categories are handled differently at every layer.
Workspace data is stored in the local encrypted database and can optionally be synced via E2E encrypted cloud sync. Secrets are stored in your operating system keychain and are never included in cloud sync by default. You can explicitly opt in to syncing specific secrets, but the default behavior is to keep them local-only. This means that even if someone gains access to a synced workspace, they do not get the keys to your kingdom.
When you share a collection with a team member, RESTK automatically strips secret values and replaces them with variable references. The receiving team member configures their own secret values locally. This pattern — shared structure with local secrets — gives you the collaboration benefits of cloud-based tools with none of the secret exposure risk.
For teams that need to share secrets (such as a shared staging API key), RESTK supports encrypted secret sharing through a separate, audit-logged channel. Every access to a shared secret is logged, and secrets can be rotated or revoked centrally.
How RESTK Compares on Privacy and Security
A transparent comparison of privacy and security capabilities across API testing tools.
| Feature | RESTK | Postman | Insomnia |
|---|---|---|---|
| Local-first data storage | |||
| E2E encrypted cloud sync | |||
| OS keychain integration | |||
| Works without account | |||
| Zero-knowledge architecture | |||
| Granular RBAC | |||
| Audit logging | |||
| Air-gapped support | |||
| Selective secret sync | |||
| GDPR by architecture |
The comparison is stark because the architectural decisions are fundamentally different. Postman and Insomnia adopted cloud-first models where data lives on their servers and local storage is either unsupported or deprecated. This means features like E2E encryption, zero-knowledge sync, and OS keychain integration are either impossible or extremely difficult to retrofit.
RESTK started with local-first as the foundation and built cloud features on top of that. This is why privacy and security features that would require fundamental re-architecture in other tools are natural extensions of RESTK's existing design.
Built for Enterprise and Government
RESTK meets the security requirements that regulated industries and government agencies demand from their developer tools.
On-Premise Deployment
Deploy RESTK sync infrastructure within your own network. Keep all collaboration features while ensuring data never crosses your network boundary.
SSO / SAML Integration
Integrate with your existing identity provider. Support for Okta, Azure AD, Google Workspace, and any SAML 2.0 compatible provider.
Custom Encryption Keys
Bring your own encryption keys (BYOK) for cloud sync. Integrate with your organization's key management service (AWS KMS, Azure Key Vault, GCP KMS).
Compliance Reporting
Generate compliance reports for SOC 2, ISO 27001, HIPAA, and FedRAMP audits. Automated evidence collection for your security reviews.
Government agencies operating under FedRAMP, ITAR, or CMMC requirements need tools that can operate within strictly controlled environments. RESTK's offline-first architecture means it works in air-gapped networks with zero external dependencies. No license server to call home, no telemetry endpoints, no CDN-hosted assets — the application is fully self-contained.
For healthcare organizations subject to HIPAA, RESTK ensures that no protected health information (PHI) in API request or response payloads is transmitted to third-party servers. The local-first model eliminates the need for Business Associate Agreements (BAAs) with your API testing tool vendor, because no data processing occurs outside your control.
Financial services teams dealing with PCI DSS, SOX, and regional financial regulations benefit from RESTK's comprehensive audit logging, role-based access control, and encrypted storage. Every action is traceable, every access is authorized, and every piece of data is encrypted — both at rest and in transit.
Compliance Ready
RESTK's architecture is designed to satisfy the security controls required by modern compliance frameworks.
Our Security Principles
The commitments that guide every security decision we make at RESTK.
Your data is yours
We will never mine, analyze, or monetize your API data. We will never train AI models on your workspace content. We will never sell aggregated insights about your API usage. Your data exists to serve you, not us.
Local by default, cloud by choice
Every feature in RESTK works without a cloud connection. Cloud sync is always opt-in, always encrypted, and always reversible. You can delete all cloud data at any time and continue working locally without losing anything.
Zero-knowledge when syncing
When you use cloud sync, we cannot read your data. Our servers store encrypted blobs. We do not have your encryption key. We cannot comply with data requests for content we cannot decrypt. This is by design.
Transparent and auditable
Our security architecture is documented publicly. We undergo regular third-party security audits. We publish the results. We maintain a public vulnerability disclosure program and respond to reports within 24 hours.
Minimal data collection
We collect only what is necessary to provide the service: crash reports (opt-in), basic usage analytics (opt-in), and account information for cloud sync users. You can disable all telemetry and still use every feature.
Ready for API testing you can trust?
Download RESTK and experience an API tool built with security and privacy as the foundation, not an afterthought.