AgentShield

Security scanner for AI agent extensions - offline-first, multi-framework, SARIF output.

AgentShield scans AI agent extensions for security vulnerabilities before they reach production. It runs locally as a single Rust binary, shares no source code with a service, and emits console, JSON, SARIF, and HTML reports.

AgentShield is currently aligned with the 0.8.4 release line.

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Why AgentShield?

AI agents are being connected to tools that can execute commands, read and write files, make HTTP requests, install packages, and call external services. A single malicious or poorly-written extension can:

• Exfiltrate credentials by reading environment variables or local secret files and sending them to an attacker-controlled endpoint.
• Execute arbitrary commands by passing user-controlled input into shell or process APIs.
• Install backdoors at runtime through package manager calls inside tool handlers.
• Proxy SSRF requests by fetching URLs derived from tool arguments.
• Leak sensitive data to model context through unguarded prompts, tool results, or rule files.

AgentShield catches these patterns with static analysis, framework adapters, policy evaluation, suppressions, baselines, egress policy generation, attestations, and SARIF output for GitHub Code Scanning.

How it compares

Feature	AgentShield	mcp-scan	Invariant Labs
Rust single binary	Yes	No	No
Offline / local-first	Yes	Partial	No
Multi-framework adapters	Yes	MCP-focused	MCP-focused
Static analysis	tree-sitter + targeted parsers	Regex-oriented	Runtime/cloud-oriented
Cross-file sanitizer analysis	Yes	No	No
SARIF output	Yes	No	No
GitHub Action	Yes	No	No

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Quick Start

GitHub Action

Add to .github/workflows/security.yml:

name: Agent Security
on: [push, pull_request]

jobs:
  scan:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: limaronaldo/agentshield@v1
        with:
          path: '.'
          fail-on: 'high'
          ignore-tests: true
          upload-sarif: true

Findings appear as PR annotations and in the repository's Security > Code scanning tab when SARIF upload is enabled.

CLI

# Install from crates.io
cargo install agent-shield

# Scan current directory
agentshield scan .

# Scan with a specific format and policy threshold
agentshield scan ./my-agent-extension --format sarif --fail-on medium --output results.sarif

# Skip test files
agentshield scan ./my-agent-extension --ignore-tests

# Generate a standalone HTML report
agentshield scan ./my-agent-extension --format html --output report.html

# List all rules
agentshield list-rules

# Create starter config
agentshield init

Pre-built binaries

Download from the latest release for Linux, macOS, and Windows targets.

For container consumers, the release image tag is:

ghcr.io/aiconnai/agentshield:0.8.4

Docker

The GHCR image is built with the full feature set, including runtime wrap support. The image is published for linux/amd64 and linux/arm64.

docker pull ghcr.io/aiconnai/agentshield:0.8.4
docker run --rm -v "$PWD:/scan" ghcr.io/aiconnai/agentshield:0.8.4 scan .
docker run --rm ghcr.io/aiconnai/agentshield:0.8.4 --version

If the GHCR package is private in your organization, authenticate first:

gh auth refresh -h github.com -s read:packages
gh auth token | docker login ghcr.io -u "$(gh api user --jq .login)" --password-stdin

From source

git clone https://github.com/limaronaldo/agentshield.git
cd agentshield
cargo build --release
./target/release/agentshield scan /path/to/agent-extension

Token-Optimized Local Checks with RTK

AgentShield can produce noisy command output during local development, especially from cargo test, cargo clippy, and scanner runs that emit JSON or SARIF. If rtk is installed, use the optional wrapper to reduce output shown to humans and coding agents:

scripts/rtk-check.sh quick
scripts/rtk-check.sh test
scripts/rtk-check.sh clippy
scripts/rtk-check.sh scan-fixture

The wrapper is intentionally local-only. RTK filters local command output only. It must not alter AgentShield JSON, SARIF, HTML, or console output contracts consumed by users, clients, CI, or GitHub Code Scanning.

Use raw output for debugging, audit, and security decisions:

scripts/rtk-check.sh raw -- cargo test
scripts/rtk-check.sh raw -- cargo run -- scan tests/fixtures/mcp_servers/safe_calculator --format sarif --output target/agentshield/scan.sarif

Policy:

• Use filtered output for fast local feedback.
• Use raw output when investigating test failures, parser bugs, detector behavior, or security-sensitive findings.
• Always write complete json and sarif reports to files when clients or CI consume them.

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Supported Frameworks

AgentShield runs all matching adapters in a repository instead of stopping at the first match.

Framework	Status	Adapter coverage
MCP (Model Context Protocol)	Supported	MCP server manifests, Python/TypeScript/JavaScript source, tool schemas, dependencies, provenance
OpenClaw	Supported	SKILL.md skill files plus related source/dependency surfaces
Hermes Agent	Supported	Hermes config/profile files, mcp_servers, .hermes.md, skill trees, optional MCP manifests
CrewAI	Supported	Python projects detected from dependency metadata or imports
LangChain / LangGraph	Supported	LangChain/LangGraph dependency metadata, imports, and langgraph.json
GPT Actions	Supported	Action/OpenAPI-style surfaces for custom GPT integrations
Cursor Rules	Supported	Cursor rule files and related agent guidance surfaces

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CLI Commands

Command	Purpose
agentshield scan [path]	Scan an agent extension directory and emit console, JSON, SARIF, or HTML output.
agentshield list-rules	List available detection rules as a table or JSON.
agentshield doctor [path]	Print environment, config, compile-feature, and adapter diagnostics.
agentshield init	Generate a starter .agentshield.toml config file.
agentshield suppress <fingerprint>	Add a suppression entry with a required reason and optional expiry.
agentshield list-suppressions	Show suppressions configured in .agentshield.toml.
agentshield certify [path]	Generate a DSSE attestation envelope for scan results.
agentshield wrap --policy <path> -- <command>	Enforce an egress policy through a local HTTP proxy when built with the runtime feature.

Useful scan options include --config, --format, --fail-on, --output, --ignore-tests, --baseline, --write-baseline, and --emit-egress-policy.

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Detection Rules

AgentShield ships built-in rules for command execution, credential exfiltration, SSRF, arbitrary file access, runtime package installation, self-modification, prompt injection surfaces, excessive permissions, dependency hygiene, dynamic code execution, metadata service access, download-and-execute flows, overbroad filesystem capabilities, unsafe deserialization, archive traversal, and secret leakage.

Use the CLI for the authoritative rule list in your installed version:

agentshield list-rules
agentshield list-rules --format json

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Output Formats

Format	Flag	Use case
Console	--format console	Local development default
JSON	--format json	Programmatic consumption and fingerprint extraction
SARIF	--format sarif	GitHub Code Scanning and compatible tools
HTML	--format html	Shareable standalone reports

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Configuration

Trust workflows

AgentShield includes trust workflow documentation for baselines, suppressions, certification attestations, and egress enforcement:

• docs/BASELINES.md: write and use .agentshield-baseline.json for known findings.
• docs/SUPPRESSIONS.md: suppress individual findings by fingerprint with required reasons and optional expiry.
• docs/CERTIFICATION.md: generate unsigned or Ed25519-signed DSSE attestations.
• docs/EGRESS.md: emit agentshield.egress.toml and enforce it with agentshield wrap.

Release binaries are built with the full feature set, including Python parsing, TypeScript parsing, and runtime wrap support. If building from source, use cargo build --features full --release to include agentshield wrap.

Create .agentshield.toml in your project root or run agentshield init:

[policy]
# Minimum severity to fail the scan: info, low, medium, high, critical
fail_on = "high"

# Rules to skip entirely
ignore_rules = ["SHIELD-008"]

# Downgrade specific rules
[policy.overrides]
"SHIELD-012" = "info"

[scan]
# Skip test files before parsing
ignore_tests = true

Suppressions can be added through agentshield suppress <fingerprint> --reason "..." after obtaining finding fingerprints from JSON output.

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Exit Codes

Code	Meaning
0	Scan passed with no findings above threshold
1	Scan failed with findings above threshold
2	Scan error, such as invalid config or no supported adapter found

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Language Support

Language	Parser	Feature flag
Python	tree-sitter AST with regex source/sink patterns	python (default)
TypeScript/TSX	tree-sitter AST with fallback patterns	typescript (default)
JavaScript/JSX	tree-sitter AST through TypeScript grammar support	typescript (default)
Shell	Regex parser	always on
JSON Schema / OpenAPI-style schemas	Schema parser	always on

Both tree-sitter parsers are feature-gated:

cargo build --no-default-features
cargo build --features python
cargo build --features full

The full feature enables language parsers plus the runtime proxy used by agentshield wrap.

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Architecture

CLI / GitHub Action / Library API
       |
       v
Scan Engine -> ScanReport
       |
       v
Adapters -> Parsers -> Cross-file analysis -> Unified IR (ScanTarget)
       |
       v
Rule Engine -> Policy / Suppressions / Baseline filtering
       |
       v
Console / JSON / SARIF / HTML / DSSE attestation

Adapters translate framework-specific files into a unified intermediate representation. Detectors consume only that IR, so new frameworks can be added without rewriting every rule. Policy, suppressions, and baselines are separate from detection so scans remain explainable and repeatable.

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Development

cargo test
cargo clippy -- -D warnings
cargo fmt --check
cargo run -- scan tests/fixtures/mcp_servers/vuln_cmd_inject
cargo run -- list-rules

For release-specific notes, see docs/releases/0.8.4.md and docs/RELEASE_CHECKLIST.md.