# Best AI coding agent security tools in 2026: the buyer's shortlist

> Six tools for securing AI coding agents like Claude Code, compared on five checks you can verify. ranwhat is ours and ranks first; the method is shown.

Canonical: https://ranwhat.com/guides/best-ai-coding-agent-security-tools
Last updated: 2026-10-20

For one developer running coding agents on their own machine, the best AI coding agent security tool is ranwhat: it reads what thirty agents ran and finds the secrets they left behind. For a company that needs enforcement and one account, GitGuardian's ggshield is the stronger pick, and Snyk Agent Scan is the one for MCP servers and skills. Six tools, five checks anyone can verify. ranwhat is ours, so read the method before the ranking.

```
$ uvx ranwhat check
```

[Install](https://ranwhat.com/install)

By Matija Mikulinec, who builds ranwhat ([about](https://ranwhat.com/about)). Every fact checked against each project's own documentation under Sources, on 20 October 2026, and re-checked every 30 to 90 days.

## Key takeaways

Which tool is best depends on who is buying. These are the five answers, and the rest of the page is the evidence for them.

- **Disclosure**: We make ranwhat and we rank it first. The five checks below favour a developer working alone, which is who ranwhat is built for, and we say where each rival beats it.
- **One developer**: [ranwhat](https://ranwhat.com/guides/best-ai-coding-agent-security-tools#ranwhat) reads the saved history of thirty coding agents, applies sixteen rules for risky actions and finds credentials left in transcripts. It needs no account. It is also the youngest tool here: its repository was created on 22 September 2026.
- **Live guard**: [Stroq](https://ranwhat.com/guides/best-ai-coding-agent-security-tools#stroq) is the closest local-first rival. Its hooks can deny a call that would send a known secret out, across six agents, and it can link a risky command to the content that led to it.
- **A company**: [ggshield](https://ranwhat.com/guides/best-ai-coding-agent-security-tools#ggshield) puts hooks into eight AI coding tools and blocks secrets in prompts, file reads, shell commands and MCP calls. It needs a GitGuardian API key and lets calls through when it cannot reach the API.
- **MCP and skills**: [Snyk Agent Scan](https://ranwhat.com/guides/best-ai-coding-agent-security-tools#snyk) checks the MCP servers and skills of fourteen agents for tool poisoning and prompt injection. It needs a Snyk token and sends configuration details to Snyk for analysis.
- **Repository scanners**: [Gitleaks](https://ranwhat.com/guides/best-ai-coding-agent-security-tools#gitleaks) and [TruffleHog](https://ranwhat.com/guides/best-ai-coding-agent-security-tools#trufflehog) find secrets in code and git history. Neither reads agent transcripts out of the box, and that is where an agent's leaked keys end up.

## What AI coding agent security tools actually are (and what they are not)

A coding agent such as Claude Code, Codex or Cursor runs shell commands, reads your files and holds your tokens. The tools in this category do one or more of five jobs.

- **Audit**: Read the history an agent already wrote and report what it did and which secrets it holds. This works after the fact, so it can only tell you.
- **Guard**: Run a hook that stops a tool call, or asks you, before it runs. This is the only job that prevents anything.
- **Repository scan**: Find secrets in code and git history, in pre-commit and in CI. It catches what an agent committed, not what it printed.
- **Supply chain**: Check the MCP servers and skills an agent loads for malicious instructions, such as a poisoned tool description.
- **Governance**: Central policy, reporting and enforcement for a security team across many machines.

It is not LLM safety, which is about jailbreaks and harmful output, and it is not a code-quality review. No tool on this page stops prompt injection outright. That is why the [prompt injection guide](https://ranwhat.com/guides/prompt-injection-coding-agents) and the [secure-by-default setup](https://ranwhat.com/guides/secure-by-default-ai-coding-agent-setup) put a boundary first (a sandbox, deny rules, scoped tokens) and a scanner second. For the order to do all of it in, see the [security checklist](https://ranwhat.com/guides/ai-coding-agent-security).

## How we ranked these tools

Five yes-or-no checks, each answerable from a project's public documentation. A tool's rank is the number of checks it meets. Ties go to the tool that supports more coding agents. There are no weights and no scores out of ten.

- **1 Reads history**: It reads the saved history of five or more coding agents, so it can audit what already ran.
- **2 Can block**: It can stop a coding agent's tool call before it runs, through a hook.
- **3 Stays local**: It works without an account and sends nothing off your machine unless you ask it to.
- **4 Open source**: It is published under an open-source licence.
- **5 Finds transcript secrets**: With no extra setup, it finds credentials already sitting in agent session files.

These checks describe one buyer: a developer or small team running agents on their own machines. They favour ranwhat because ranwhat is built for that buyer, and checks 1 and 5 are the gap it was made to fill. A company with a security team and an audit requirement should weigh enforcement and central reporting more, and would rank GitGuardian higher. We did not review the sales-led enterprise platforms, such as Pillar Security, Nightfall and Endor Labs. They are aimed at security teams and we have not tested them.

## The best AI coding agent security tools in 2026

In rank order, with what each does, what it sends off your machine, what it costs and where it falls short. Each section ends with who it suits. Checks are counted against the five above.

### 1. ranwhat, best for auditing what your agents already did

ranwhat reads the history coding agents already write to disk. `ranwhat watch` runs sixteen rules over it: credential reads, `rm -rf`, force pushes, `npm publish` and more. `ranwhat clean` finds credentials sitting in plaintext in transcripts and says what to rotate first, and `ranwhat scan` scores what a token allows from a catalogue of 204 scopes across twelve providers.

- **Checks met**: 5 of 5.
- **Agents**: Claude Code and twenty-nine others, among them Codex, Gemini CLI, GitHub Copilot CLI and Cursor. `ranwhat sources` lists each one and where it looks.
- **Data**: Local commands read your disk and send nothing. The commands that check a token (`live`, `callers`, `--pull-usage`, `revoke`) ask only the provider that issued it, and `update` and `login` talk to ranwhat.com. No account for local use, no telemetry.
- **Licence and price**: MIT. Free on your own machine, nothing held back. Plus is €12 a month or €120 a year per organisation, and covers only what needs a server.
- **Limits**: It reports after the fact. The one thing it can block is a call you opt in to with its Claude Code hook, and that hook is Claude Code only. It does not detect prompt injection, and `reach` flags risky MCP configuration without inspecting a server's code or tool descriptions. It has no central view for a team yet. Version 0.7.0.
- **Best suited for**: A developer or small team who runs coding agents on their own laptops and wants to know what those agents ran and what leaked. Run `uvx ranwhat check` to try it.

### 2. Stroq, best for guarding the next Claude Code, Codex or Cursor session

Stroq is an open-source command-line tool written in TypeScript. It looks through saved Claude Code, Codex and Cursor sessions for credential values it already knows about, then installs local hooks that can deny a call that would send one of those values out. Its provenance feature ties some later actions to the earlier tool output that led to them, which ranwhat does not do.

- **Checks met**: 4 of 5. It reads the history of three agents, below the five the first check asks for.
- **Agents**: Session scanning covers Claude Code, Codex CLI and Cursor. Hooks also cover Copilot CLI, Windsurf and Antigravity, and there is an OpenClaw plugin and a stdio MCP proxy.
- **Data**: Its README says the hooks make no outbound network calls and that it has no telemetry. No account.
- **Licence and price**: Apache-2.0, free. It needs Node.js 22 or newer.
- **Limits**: Its README warns that how much it covers varies with the agent host, its version and the channel, and that it works from credentials it can find on your machine, so a key that was rotated away or never stored there can slip through. The repository was created on 4 September 2026 and its latest release, v0.25.1, is dated 13 October 2026.
- **Best suited for**: A developer who wants live blocking across several agents more than a record of what happened.

### 3. GitGuardian ggshield, best for teams that want enforcement and one account

ggshield is GitGuardian's command-line client. It started as a secret scanner for git, and it now installs hooks into AI coding tools. Per its documentation it checks prompts before they reach the model, checks commands, file reads and MCP calls before they run, and checks tool output afterwards. It blocks when it finds a secret, which makes it the strongest enforcement on this list.

- **Checks met**: 2 of 5 (can block, open source).
- **Agents**: Cursor, Claude Code, Codex, Copilot CLI, VS Code, Mistral Vibe, Kiro and Junie CLI. Junie inside a JetBrains IDE is not covered.
- **Data**: It needs a GitGuardian API key and reaches GitGuardian's API. The documentation page does not say what scanned content is sent. If it cannot scan, it lets the interaction through and shows a warning.
- **Licence and price**: The client is MIT. We did not check GitGuardian's plans.
- **Limits**: It guards live interactions. It is not an audit of the history already on your disk.
- **Best suited for**: Teams that already use GitGuardian and want one account, one policy and enforcement inside the agent.

### 4. Gitleaks, best for free secret scanning of repositories

Gitleaks scans git repositories, directories and standard input for secrets, and runs as a pre-commit hook or a GitHub Action. It installs through Homebrew, Docker or a prebuilt binary. Its README describes no AI agent feature, and says the project is feature complete, with future releases limited to security patches while its author turns to a successor project.

- **Checks met**: 2 of 5 (stays local, open source).
- **Agents**: None. It is not agent-aware. You can point its directory scan at a transcript folder yourself, but it does not know where each agent keeps history or how to read each format.
- **Data**: It scans what you point it at. Its README makes no telemetry statement. No account.
- **Licence and price**: MIT, free.
- **Limits**: It finds secrets in files and git history. A key an agent printed with `cat .env` lives in a transcript outside the repository, where it is never looked at.
- **Best suited for**: Anyone who wants a fast, free scan of code and git history in pre-commit and CI, whichever agent wrote the code.

### 5. Snyk Agent Scan, best for checking MCP servers and agent skills

Snyk Agent Scan, formerly MCP-Scan from Invariant Labs, which Snyk bought in 2025, scans the MCP servers, skills and configuration files that agents use. It reports issues such as prompt injection, tool poisoning, tool shadowing and hardcoded secrets. On this one job it goes further than anything else here: ranwhat's `reach` flags risky MCP configuration, and Agent Scan examines the tools themselves.

- **Checks met**: 1 of 5 (open source). It scans configuration, not transcripts, and it reports instead of blocking.
- **Agents**: Fourteen, including Claude Code, Cursor, Codex, Gemini CLI, Windsurf, VS Code and GitHub Copilot.
- **Data**: It needs a Snyk account and an API token. Its README says it sends agent details, MCP server configurations, the names and descriptions of tools, and skill content to Snyk for analysis, with secrets redacted first.
- **Licence and price**: Apache-2.0, closed to outside code contributions. We did not check Snyk's plans.
- **Limits**: Its README marks the CLI output as experimental and subject to change. It has a `--ci` mode that exits non-zero on findings.
- **Best suited for**: A team that runs many MCP servers or shares skills, and already works with Snyk.

### 6. TruffleHog, best for finding out whether a leaked secret still works

TruffleHog finds credentials and, by default, tests whether they are still live by calling the provider's API with the value it found. It scans git, GitHub, GitLab, Docker images, cloud storage and the filesystem, and its README counts over 700 detectors that verify against the provider.

- **Checks met**: 1 of 5 (open source).
- **Agents**: None described in its README.
- **Data**: Verification sends the secret it found to the provider that issued it. Verification can be turned off with `--no-verification`. No account.
- **Licence and price**: AGPL-3.0, free. The copyleft licence matters if you plan to embed it in your own product.
- **Limits**: Like Gitleaks, it is built for repositories and infrastructure, not for the way an agent stores its history.
- **Best suited for**: Responding to a known leak, when the question is whether the key still opens anything.

## Side-by-side comparison

The five ranking checks for each tool, then the facts behind them. A tool that meets more checks is ranked higher, and ties go to the tool with more agents.

| Tool | Reads history | Can block | Stays local | Open source | Transcript secrets | Met |
| --- | --- | --- | --- | --- | --- | --- |
| **ranwhat** | Yes, 30 agents | Yes, Claude Code hook | Yes | Yes | Yes | 5 of 5 |
| **Stroq** | No, 3 agents | Yes | Yes | Yes | Yes | 4 of 5 |
| **ggshield** | No | Yes, fails open | No, API key | Yes | No | 2 of 5 |
| **Gitleaks** | No | No | Yes | Yes | No | 2 of 5 |
| **Snyk Agent Scan** | No, configuration only | No | No, Snyk token | Yes | No | 1 of 5 |
| **TruffleHog** | No | No | No, verifies with providers | Yes | No | 1 of 5 |

| Tool | Agents | Licence | Price |
| --- | --- | --- | --- |
| **ranwhat** | 20 read, 1 hooked | MIT | Free; Plus €12 a month per organisation |
| **Stroq** | 3 read, 6 hooked | Apache-2.0 | Free |
| **ggshield** | 8 hooked | MIT client | Not checked |
| **Gitleaks** | None | MIT | Free |
| **Snyk Agent Scan** | 14 scanned | Apache-2.0 | Not checked |
| **TruffleHog** | None | AGPL-3.0 | Free |

“Not checked” means we did not verify the vendor's plans and would rather say so than guess. For how ranwhat's own free and paid tiers differ, see [pricing](https://ranwhat.com/pricing).

## Which tool fits your use case

The ranking is one lens. Start from what you are trying to do.

| If you are | Start with | Why |
| --- | --- | --- |
| A solo developer using Claude Code, Codex or Cursor | ranwhat | It audits thirty agents, finds leaked keys and needs no account. Add a hook for live blocking. |
| A developer who wants a live guard on several agents | Stroq | Hooks for six agents that can deny a call carrying a known secret. |
| A team already on GitGuardian | ggshield | One account and one policy, with blocking in eight AI coding tools. |
| A team with many MCP servers and shared skills | Snyk Agent Scan | It examines tool descriptions and skills, which the other tools here do not. |
| Scanning code and git history in CI | Gitleaks | Fast and free, whichever agent wrote the code. |
| Responding to a leak and needing to know if the key is live | TruffleHog | It tests the key against the provider that issued it. |
| A security team with an audit requirement | ggshield, or an enterprise platform | ranwhat has no central policy or reporting for a team yet. |

These do not exclude each other. A repository scanner in CI, a guard hook in the agent and an audit of its history cover three different places a secret can leak from.

## What results look like

We have no customer case studies to quote and will not invent any. What we can show is the tool's own output on a bundled example, not a real machine.

```
$ ranwhat watch --days 90 (bundled example)
2 critical  2 high

* Credential material accessed   Bash
    cat ~/.ssh/id_rsa
    -> The agent read a file whose only purpose is to hold secrets.
       Whatever it read is now in a model context you do not control.

* Package or release published   Bash
    npm publish
    -> Something was pushed to a registry other people may install from.

Read locally. Nothing was transmitted.
```

The [example report](https://ranwhat.com/example-report) shows the full output for a fictional project, and [the watch page](https://ranwhat.com/watch) lists every rule and what it flags.

## Common questions

### What is the best AI coding agent security tool?

There is no single best tool. For one developer on their own machine, ranwhat covers the most agents and needs no account. For a team that wants enforcement and one account it is ggshield, and for MCP servers and skills it is Snyk Agent Scan.

### How do I stop an AI coding agent leaking my API keys?

Keep keys out of its reach first: deny reads of `.env` and cloud credential files, sandbox its network and give it a scoped token. Then add a guard hook for what slips past, and check its history for what already leaked. The [.env guide](https://ranwhat.com/guides/claude-code-env-secrets) covers the first step.

### What is the difference between a secret scanner and an agent security tool?

A scanner such as Gitleaks or TruffleHog looks in code and git history, where a committed key ends up. An agent tool also looks where the agent's own output goes: transcripts hold every command's output in plaintext, including a key printed by `cat .env`. Those files sit outside the repository, so a repository scanner never sees them.

### How far back can I see what a coding agent ran?

As far back as the agent keeps its history. Claude Code deletes transcripts after 30 days by default, and other agents differ, as [where each agent keeps history](https://ranwhat.com/guides/ai-coding-agent-history-locations) shows. For a record from now on, add a hook or OpenTelemetry.

### What does it cost to secure a coding agent?

ranwhat, Stroq, Gitleaks and TruffleHog are free and open source. ggshield and Snyk Agent Scan are open-source clients that need an account with their vendor, and we did not check those plans. ranwhat's paid Plus is €12 a month per organisation and covers only what needs a server.

### What data does each tool send off my machine?

ranwhat and Stroq work locally, and ranwhat goes online only for commands that check a token or talk to ranwhat.com. ggshield and Snyk Agent Scan need an account: Snyk says it sends configuration and skill content with secrets redacted, and ggshield's page does not say what it sends. Gitleaks scans locally, and TruffleHog sends a found secret to its provider to verify it unless you switch that off.

### How do I check MCP servers and skills for malicious instructions?

Run a scanner built for it, such as Snyk Agent Scan, and read each server's configuration yourself. `ranwhat reach` lists the servers and credential files your agents can reach and flags risky shapes, but it does not inspect a server's tool descriptions. The [MCP server guide](https://ranwhat.com/guides/mcp-server-security-coding-agents) covers what to approve.

### How current is this comparison?

Every fact comes from a project's own documentation as of 14 October 2026, and we re-check this page every 30 to 90 days. If something here is wrong, [tell us](https://ranwhat.com/contact) and we will correct it and date the change.

## Try ranwhat free (no account needed)

One command shows what your agents ran and what they left behind.

It reads the history your agents already wrote, on your own machine. It changes nothing and says what to rotate first. It needs Python 3.9 or newer and nothing else. Nothing is held back from the free version, and no card is asked for. If it finds something, the [rotation guide](https://ranwhat.com/guides/rotate-leaked-api-key-ai-agent) goes provider by provider.

```
$ uvx ranwhat check
```

[Install](https://ranwhat.com/install)

More guides are on the [guides](https://ranwhat.com/guides) page, in the order worth doing them in the [security checklist](https://ranwhat.com/guides/ai-coding-agent-security).

## Sources

Every claim about another tool comes from the page it is listed against, read on 14 October 2026.

- [ranwhat READMEagents, rules, hook, what goes online, licence](https://github.com/MatijaMiki/ranwhat/blob/main/README.md)
- [Stroq on GitHubagents, hooks, local-only statement, Node.js 22, Apache-2.0](https://github.com/AGGIB/Stroq)
- [GitGuardian: secret scanning for AI coding toolssupported tools, hook stages, blocking, API key, fails open](https://docs.gitguardian.com/ggshield-docs/integrations/ai-coding-tools/secret-scanning-for-ai-coding-tools)
- [Gitleaks on GitHubwhat it scans, MIT, feature complete](https://github.com/gitleaks/gitleaks)
- [Snyk Agent Scan on GitHubagents, issue types, token, data sent, Apache-2.0](https://github.com/snyk/agent-scan)
- [SiliconANGLE: Snyk acquires Invariant LabsJune 2025, MCP-Scan's origin](https://siliconangle.com/2025/06/24/snyk-acquires-invariant-labs-expand-ai-agent-security-capabilities/)
- [TruffleHog on GitHubverification, sources, detectors, AGPL-3.0](https://github.com/trufflesecurity/trufflehog)