Governed MCP tools. Sealed in WASM.
Write tools in any language, compile to WebAssembly, and run them with auditable policies and least-privilege security.
Trusted by platform teams at
"mcpfuse transformed how we manage internal tooling. Our security team finally has visibility into what tools are doing, and our developers can ship faster knowing their tools will pass review."
Default-deny by design.
Tools run sealed in a WASM codebox. Capabilities open only when declared in a manifest—fully auditable.
# Permissions manifeststorage: allow: - uri: "fs:///tmp/cache" access: ["read", "write"]network: allow: - host: "api.weather.com"environment: allow: - key: "API_KEY"How it works
From code to production in four steps, with security built-in at every stage.
Build
Write your tool in any language. Rust, Go, TypeScript—compile it to WebAssembly.
export function getWeather(city: string) {
const res = await fetch(
`https://api.weather.com/${city}`
);
return res.json();
}Declare Permissions
Define capabilities in a manifest: network allowlists, filesystem access, secrets.
# Permissions
storage:
allow:
- uri: "fs:///tmp/cache"
access: ["read", "write"]
network:
allow:
- host: "api.weather.com"
environment:
allow:
- key: "API_KEY"Review & Sign
Policy checks, team approvals, and cryptographic attestation for supply chain integrity.
Run Anywhere
Deploy to secure runtimes. Connect to Slack, Teams, agents, and production workflows.
Everything you need for governed tooling
Built for platform teams who need security without sacrificing developer experience.
Tool Registry & Versioning
Centralized registry with semantic versioning, rollback support, and dependency tracking.
Permission Manifest
Declare capabilities explicitly: network, filesystem, environment variables, secrets.
Policy Engine
Define allow/deny rules, egress allowlists, and custom policies per team or org.
Audit Logs
Complete trail of who ran what, when, with full input/output capture.
Attestation & Signing
Cryptographic signatures and SLSA attestation for supply chain integrity.
Runtime Sandboxing
WASM codebox with resource limits, isolated execution, and configurable constraints.
Secrets & Config
Secure secret injection, environment management, and config versioning.
CI/CD Integration
GitHub Actions, GitLab CI, and webhook support for automated workflows.
Observability
Metrics, traces, and structured logs with OpenTelemetry support.
Security & governance deep dive
Built from the ground up with security as a first-class concern, not an afterthought.
Least Privilege by Default
- Tools start with zero permissions
- Explicit capability declaration required
- Runtime enforcement of declared limits
- Network egress allowlists
Auditable Everything
- Every execution logged with full context
- Input/output capture for debugging
- Tamper-evident audit trail
- Export to SIEM and compliance tools
Enterprise Controls
- SSO/SAML integration
- Role-based access control
- Org-wide policy enforcement
- Compliance reporting (SOC 2, GDPR)
Security Architecture
Developer experience first
A CLI and SDK that feels familiar, with security that stays out of your way.
# Initialize a new tool
$ mcpfuse init my-slack-bot
✓ Created manifest.toml
✓ Created src/main.rs
# Build to WebAssembly
$ mcpfuse build --target wasm32
✓ Compiled to WebAssembly (124KB)
✓ Generated permissions hash
# Validate against policies
$ mcpfuse policy validate
✓ Network allowlist: hooks.slack.com
✓ No filesystem write access
✓ Secrets: SLACK_WEBHOOK_URL
# Publish with signing
$ mcpfuse publish --sign
✓ Signed with attestation
✓ Published to registry v1.0.3
# Run with enforced policy
$ mcpfuse run my-slack-bot@1.0.3
✓ Policy enforced
✓ Execution loggedIntegrations
Plug into your existing SDLC and observability stack.
Simple, transparent pricing
Start free, scale as your team grows.
Free
For individual developers and experimentation.
- Local development & testing
- Up to 5 tools in registry
- Community support
- Basic audit logs (7 days)
- Single user
Team
For teams building governed internal tools.
- Unlimited tools in registry
- Team collaboration & reviews
- Custom policies per team
- Full audit logs (90 days)
- Slack & Teams integration
- Priority support
Enterprise
For organizations with advanced security needs.
- Everything in Team
- SSO/SAML authentication
- Advanced policy engine
- Unlimited audit retention
- Dedicated support & SLA
- On-premise deployment option
Frequently asked questions
Everything you need to know about mcpfuse.
Ship tools your security team will approve.
Join hundreds of platform teams building governed, auditable tooling with mcpfuse.