Open source integration layer for AI agents with secure, multi-tenant support
A fax API and MCP server for AI agents to send and receive faxes with receipts
Stage
Not given
Not given
Founded
Not given
2023
Based in
Not given
US
Pricing model
Freemium
Paid
Pricing
Hobby: $0/mo with up to 50 connections, 100k webhook events, unlimited managed permissions/auth pages, up to 3 team members, and Discord community support. Pro: $200/mo with unlimited connections, unlimited webhook events, unlimited managed permissions/auth pages, unlimited team members, and Slack s
$0.039 per page sent, $0.019 per page received, $2 per fax number per month, $10 minimum wallet top-up, optional Agent workspace $19 per month, sandbox free. Prices as of 2026-10-28.
Key features
OAuth and multi-tenant credential management
Permissions system with approval workflows
Webhooks and polling for data synchronization
Multiple integration connectors
Self-hosted and cloud-hosted options
Managed authentication pages
Agent-safe credential handling
API caching per tenant
Custom integration scaffolding
Community-contributed integrations
Document preparation with PDF, image and text rendering
Price quotes bound to document, destination and sender
Authorization by person or delegated policy
Bounded retries with circuit breaker per route
Private inbox for received faxes with signed URLs
Idempotent API calls with Idempotency-Key header
Signed webhooks with event IDs
Sandbox for free testing before production
Document retention with 30-day default and deletion option
What makes it different
Fully open source to avoid vendor lock-in
Credentials never stored in Corsair's database
Free self-hosted option with no per-seat pricing
Handles token refresh and API deprecations automatically
Works with or without AI agents
Every fax send produces a receipt with provider evidence of delivery
Agents cannot exceed their own permissions or budget limits
International fax coverage to 213 destinations with transparent pricing
MCP server with 15 tools for seamless agent integration
Per-page pricing with no minimum subscription requirement
Corsair
Fax for Agents