sovr-mcp-proxy

Transparent MCP Proxy — The Execution Firewall for AI Agents.

sovr-mcp-proxy is a superset of sovr-mcp-server. It includes all MCP Server capabilities plus a transparent proxy layer that intercepts, evaluates, and audits every agent→tool call against configurable policy rules before forwarding to downstream MCP servers.

Architecture

┌─────────────┐     ┌──────────────────┐     ┌─────────────────┐
│  AI Agent    │────▶│  sovr-mcp-proxy  │────▶│ Downstream MCP  │
│ (Claude etc) │     │  Gate-Check Layer│     │ (Stripe/GitHub) │
└─────────────┘     └──────────────────┘     └─────────────────┘
                         │
                    Policy Rules
                    Permit/Receipt
                    Audit Trail

Key Differences: Proxy vs Server

Feature	sovr-mcp-proxy	sovr-mcp-server
286 Native Tools	✅	✅
1630 SDK Routes	✅	✅
Transparent Proxy Mode	✅	❌
Downstream Server Interception	✅	❌
Spawn/Discover/Intercept/Forward	✅	❌
Multi-server Routing	✅	❌
Anti-loop Protection	✅	N/A
Hop Counter	✅	N/A

Quick Start

Install

npm install -g sovr-mcp-proxy

Claude Desktop Configuration

{
  "mcpServers": {
    "sovr-proxy": {
      "command": "npx",
      "args": ["sovr-mcp-proxy"],
      "env": {
        "SOVR_API_KEY": "sovr_sk_...",
        "SOVR_PROXY_CONFIG": "/path/to/proxy.json"
      }
    }
  }
}

Proxy Configuration (proxy.json)

{
  "downstream": {
    "stripe": {
      "command": "npx",
      "args": ["@stripe/agent-toolkit"],
      "env": { "STRIPE_SECRET_KEY": "sk_test_..." }
    },
    "github": {
      "command": "npx",
      "args": ["@modelcontextprotocol/server-github"],
      "env": { "GITHUB_TOKEN": "ghp_..." }
    }
  }
}

Every tool call to stripe or github is intercepted by SOVR's gate-check layer before forwarding.

How It Works

Spawn — On startup, sovr-mcp-proxy spawns all downstream MCP servers as child processes
Discover — Enumerates tools from each downstream server via tools/list
Intercept — When the AI agent calls any tool, the proxy evaluates it against policy rules
Gate-Check — Applies permit/deny/escalate verdict based on rules
Forward — Approved calls are forwarded to the downstream server; denied calls return an error

Security Features

HTTPS Enforcement

All non-localhost connections are validated for HTTPS. HTTP connections to external hosts are rejected.

Fail-Close / Fail-Local Degradation

Default (fail-close): If SOVR Cloud is unreachable, all gated operations are denied
Configurable (fail-local): Set SOVR_FAIL_MODE=fail-local to fall back to 20 built-in local rules

Three-State Degradation

Mode	Behavior	Use Case
`strict` (default)	Enforce all deny/escalate verdicts	Production
`record-only`	Log violations but allow execution	Emergency availability rescue
`propose-only`	Return verdict without executing	Dry-run / testing

Anti-Loop Protection

Hop counter prevents infinite proxy chains (default max: 3 hops)
Re-entry guard detects circular tool call patterns

Data Redaction

Sensitive fields (password, secret, token, key, authorization, cookie, ssn, credit_card) are automatically redacted in all logs and audit entries.

Unified Alert Dispatcher

Configurable alert routing to Webhook, Slack, PagerDuty, or OpsGenie (replaces hardcoded Telegram).

Built-in Rules (Free Tier)

Rule	Effect	Description
Destructive Commands	DENY	Blocks `rm -rf`, `mkfs`, `dd`, `shred`
DDL Operations	DENY	Blocks `DROP`, `TRUNCATE`, `ALTER`
Privilege Escalation	ESCALATE	Flags `sudo`, `chmod`, `chown` for approval
Payment APIs	ESCALATE	Flags Stripe, PayPal calls for approval
Deployment Ops	ESCALATE	Flags deploy/publish/release for approval

Environment Variables

Variable	Required	Description
`SOVR_API_KEY`	No	Connect to SOVR Cloud for expanded tools and persistent audit
`SOVR_PROXY_CONFIG`	No	Path to proxy configuration JSON
`SOVR_RULES_FILE`	No	Path to custom rules JSON file
`SOVR_PROXY_MODE`	No	`strict` / `record-only` / `propose-only` (default: `strict`)
`SOVR_FAIL_MODE`	No	`fail-close` / `fail-local` (default: `fail-close`)
`SOVR_MAX_HOPS`	No	Max proxy hop count before loop detection (default: 3)
`SOVR_TENANT_ID`	No	Tenant identifier for multi-tenant deployments
`SOVR_ACTOR_ID`	No	Actor identifier for audit trail
`SOVR_SESSION_ID`	No	Session identifier for trace correlation
`SOVR_ENDPOINT`	No	Custom Cloud endpoint (advanced)

Tier Comparison

	Free	Personal	Starter	Pro	Enterprise
Tools	8	23	48	98	274
Built-in Rules	5	15+	15+	15+	15+
Custom Rules	3	Unlimited	Unlimited	Unlimited	Unlimited
Proxy Downstream	1 server	Unlimited	Unlimited	Unlimited	Unlimited
Permit/Receipt	Local only	Cloud	Cloud	Cloud	Cloud
Audit Trail	In-memory	Persistent	Persistent	Persistent	Persistent
Approval Workflow	—	Basic	Full	Full	Full + SLA

Free tier works offline with zero configuration. Upgrade at sovr.inc/pricing.

Related Packages

sovr-mcp-server — MCP Server mode only (no proxy capabilities)

License

BSL-1.1 — Code is source-available. Free for non-commercial use. Commercial use requires a license from SOVR AI.

After the Change Date (February 18, 2030), this software converts to Apache-2.0.

SOVR — Eyes on AI. sovr.inc

sovr-mcp-proxy

sovr-mcp-proxy

Architecture

Key Differences: Proxy vs Server

Quick Start

Install

Claude Desktop Configuration

Proxy Configuration (proxy.json)

How It Works

Security Features

HTTPS Enforcement

Fail-Close / Fail-Local Degradation

Three-State Degradation

Anti-Loop Protection

Data Redaction

Unified Alert Dispatcher

Built-in Rules (Free Tier)

Environment Variables

Tier Comparison

Related Packages

License

Reviews