sabba

sabba

MCP server for security bug-finding that proves every finding by running exploits, enabling agents to verify changes and find bugs with execution-based evidence.

Category
Visit Server

README

<p align="center"> <img src="docs/img/sabba-terminal.svg" alt="SABBA - security bug-finder that proves every finding" width="920"> </p>

<h1 align="center">SABBA</h1>

<p align="center"> <b>Security Templates CLI & MCP Server for coding agents</b> that <b>prove every finding by running it</b>.<br> Claude Code, Codex, OpenCode, Cursor, and Hermes call Sabba to prove a change, find and prove bugs, vet a skill, and drive the security toolchain — authorized-scope-only.<br> If it does not run, Sabba does not report it. </p>

<p align="center"> <img src="https://img.shields.io/badge/license-Apache--2.0-blue" alt="Apache-2.0"> <img src="https://img.shields.io/badge/python-3.11%2B-3776ab" alt="Python 3.11+"> <img src="https://img.shields.io/badge/false%20positives-0%20by%20construction-2ea043" alt="zero false positives by construction"> <img src="https://img.shields.io/badge/domains-C%20%C2%B7%20C%2B%2B%20%C2%B7%20Solidity%20%C2%B7%20Python%20%C2%B7%20Go%20%C2%B7%20Java%20%C2%B7%20JS%2FTS-8957e5" alt="domains"> </p>


Most tools that use a language model ask it "is this function vulnerable?" That is close to a coin flip, even for large models, and unverified guesses bury maintainers in false positives. Sabba takes the opposite stance: a model proposes candidates, but an execution oracle runs an exploit and decides whether a security property actually broke. Nothing is reported unless the exploit reproduces. A finding is not a score, it is a re-runnable proof.

<p align="center"> <img src="docs/img/sabba-demo.gif" alt="Sabba proving a stack overflow and a heap overflow by running them" width="820"> </p>

Use it from any coding agent (MCP)

Sabba runs as an MCP server, so Claude Code, Codex, OpenCode, Cursor, and Hermes can call it. For Codex CLI, add it to ~/.codex/config.toml:

[mcp_servers.sabba]
command = "sabba"
args = ["mcp"]

For Claude Code:

claude mcp add sabba -- sabba mcp        # after installing; see Install below

Fourteen tools, most token-free: verify_change (prove a change works in any of 16 languages: a new test fails on the base and passes on the head, via the bundled Magga engine) and prove (the same differential, run natively for C/C++/EVM), verify / solve / hunt / scan (find and prove bugs), security_scan (vet a skill by running it under observation), rank, run_sandboxed, and kali_run (drive nmap / nuclei / ffuf / sqlmap and the rest, scope-enforced and sandboxed). Install the security command templates with sabba templates install. Full catalog and per-client configs in docs/AGENT_INTEGRATION.md.

Correctness and security in one server. verify_change proves the change does what it claims; prove / hunt / scan prove it added no new bug. The change-verification engine is Magga, vendored as a submodule under magga/ and driven through npx, so both halves ship as one tool.

What SABBA can do

Find a real bug and hand you the proof, not a hunch. Every finding ships with the input that triggers it and a bundle you can re-run yourself. Two real bugs in cJSON were found this way and written up in docs/scans: a stack exhaustion (CWE-674) and a heap over-read in parse_object (CWE-125).

Work across languages and across chains, with one rule. The oracle started on C and C++ memory safety and generalized into a registry of provers, one per runtime and vulnerability class. Every prover obeys the same contract: a finding is minted only from a verdict that a real, security-relevant crash happened inside the target.

Domain Runtime it proves on What counts as proven Examples
C / C++ clang + AddressSanitizer / UBSan the sanitizer reports a real memory error heap / stack overflow, use-after-free
Solidity / EVM Foundry mainnet fork attacker ETH profit or a broken solvency invariant, measured on-chain reentrancy fund-drain
Python atheris a crash raised in the target, not the harness stack exhaustion, C-extension segfault
Go go test -fuzz a recovered runtime panic at a target frame index / slice out of range, nil deref
Java / JVM Jazzer a target throwable or a bug-detector finding stack overflow, injection detectors
Node JS / TS Jazzer.js a target crash or a bug-detector finding prototype pollution, ReDoS, path traversal

Refuse to be fooled, even by a hostile harness. When a model writes the fuzz harness, a hostile target could try to steer it into faking a crash. Sabba's fuzzing provers are harness-untrusted: the fuzzer only discovers a candidate input, then a Sabba-owned reproducer re-runs it and reads the verdict from channels the harness cannot forge (a real exception's structured stack, or the parent's own measurement of a killed child). It reads no stdout, no artifact file, no magic phrase. The full model is in docs/PROVER_SOUNDNESS.md.

Prefer soundness over coverage, and say so. Where a crash cannot be soundly pinned to the target (a hang or an out-of-memory that could just as easily be the harness spinning or pre-filling the heap), Sabba surfaces it as an unverified candidate for a human, but never mints it as a finding. It would rather miss a bug than report one that did not happen.

Meet you where you work. One command, several surfaces: a scriptable CLI (verify, solve, hunt) and an interactive REPL (pictured above) that streams the model, runs tools, and renders each proof as a card. Running sabba with no arguments opens the REPL.

Use it from your own agent (MCP)

Sabba runs as a Model Context Protocol server, so Claude Code, Codex, OpenCode, OpenClaw, or any tool-calling model can spawn it and command it. The agent hands Sabba a target, Sabba runs the oracle or a prover, and hands back a verdict, so the calling agent gets a proof, not a guess.

sabba mcp          # stdio (default); or `sabba mcp --http`
claude mcp add sabba -- sabba mcp     # e.g. register it with Claude Code

Tools: verify, solve, hunt, scan, doctor, list_provers. verify, solve, and doctor need no model, so an agent can prove a suspected bug with no extra credentials. See docs/AGENT_INTEGRATION.md for per-client setup and running the reasoning on a local model.

Run it locally, and let it learn where to look

The oracle and provers never needed a model, and the model-driven parts can run on your own machine too. Point the reasoning at a local, OpenAI-compatible endpoint with SABBA_LLM_BACKEND=local, and train a small CPU risk ranker so retrieval looks at the risky functions first:

sabba mltrain          # trains a risk ranker (TF-IDF + logistic), saved to ~/.sabba

A three-tier cascade keeps work cheap: Reflex (no model: the ranker, Z3, the oracle), Resident (the local model), and Teacher (a frontier model) only for the hard cases. The verdict rule holds across tiers, so a cheaper tier costs coverage, never soundness. See docs/LOCAL_ML.md.

Why it is different

                 model / z3 / retrieval  ->  candidate input
                                                   |
                                                   v
                     +---------------------------------------+
                     |   execution oracle  /  prover         |
                     |   compile, run the exploit, measure   |
                     +---------------------------------------+
                                    |            |
                              reproduces     does not
                                    |            |
                                  FINDING     dropped

The oracle is the one gate. Whether a candidate came from the Z3 synthesizer or from the model, it is compiled and run before anything is reported. Z3 proposes an input, the oracle decides. The model proposes an input, the oracle decides. The same discipline carries to every domain in the table above: on an EVM fork the chain measures the attacker's profit, not the model, so the model cannot grade its own work.

Install

git clone --recurse-submodules https://github.com/8NobleTruths/sabba.git
cd sabba
./install.sh

That sets up an isolated environment under ~/.sabba and puts a sabba command on your PATH. Run sabba doctor to check the toolchain. Update later with sabba update, remove with sabba uninstall.

Provers use the toolchain of the domain you target: clang with AddressSanitizer for C and C++, Foundry for EVM, and atheris, go, Jazzer, or Jazzer.js for the managed languages. sabba doctor reports what is present.

Quick start

sabba                                     # opens the REPL; type /setup for guided first-run setup

# no model needed, prove a known target:
sabba verify targets/cwe121_stack_overflow
sabba solve  targets/cwe121_stack_overflow

First run opens a guided setup: /setup shows a checklist, and each step explains why it is worth doing, what happens if you skip it, and what happens when you do it. /local-llm-config detects your CPU and RAM, recommends a Qwen2.5-Coder size, and pulls it with Ollama so the model runs on your machine; /add-model-key uses a cloud model instead; /ml-config trains the risk ranker. You can select any command from the / menu. /solve and /verify prove bugs with no model at all, so they work before any setup.

Bring in a model through OpenRouter (or any OpenAI-compatible endpoint) to hunt fresh code:

export SABBA_LLM_BACKEND=openrouter
export OPENROUTER_API_KEY=...             # from openrouter.ai/keys
sabba hunt targets/cwe122_heap_overflow --model qwen/qwen-2.5-coder-32b-instruct

Keys are read from the environment, never stored in the repo, and a pre-commit hook blocks anything that looks like a credential (see CONTRIBUTING.md).

How it works, in more depth

  • docs/SABBA_AGENT_DESIGN.md - the C and C++ bug-finder: the oracle, retrieval, the Z3 synthesizer, and the reasoning agent.
  • docs/PROVERS_MULTI_DOMAIN_DESIGN.md - how the oracle generalizes into the prover registry, including Web3 and Solidity.
  • docs/PROVER_SOUNDNESS.md - the harness-untrusted verification model that makes the fuzzing provers sound against an adversarial harness.
  • docs/WATER_LAYER_DESIGN.md - the next layer: an agent that keeps its skills as runnable code, runs without a frontier model, and can be rebuilt from a seed. Provers are the skills it accumulates.

Status

The native oracle, retrieval, Z3 synthesis, the reasoning agent, and the full prover registry across C/C++, Solidity/EVM, Python, Go, Java, and Node run today, each with live proofs. The Water Layer and a broader symbolic-execution pass are next.

License

Apache-2.0. See LICENSE. The framework is open source. Trained model weights and datasets are developed separately and are not part of this repository.

Recommended Servers

playwright-mcp

playwright-mcp

A Model Context Protocol server that enables LLMs to interact with web pages through structured accessibility snapshots without requiring vision models or screenshots.

Official
Featured
TypeScript
Magic Component Platform (MCP)

Magic Component Platform (MCP)

An AI-powered tool that generates modern UI components from natural language descriptions, integrating with popular IDEs to streamline UI development workflow.

Official
Featured
Local
TypeScript
Audiense Insights MCP Server

Audiense Insights MCP Server

Enables interaction with Audiense Insights accounts via the Model Context Protocol, facilitating the extraction and analysis of marketing insights and audience data including demographics, behavior, and influencer engagement.

Official
Featured
Local
TypeScript
VeyraX MCP

VeyraX MCP

Single MCP tool to connect all your favorite tools: Gmail, Calendar and 40 more.

Official
Featured
Local
graphlit-mcp-server

graphlit-mcp-server

The Model Context Protocol (MCP) Server enables integration between MCP clients and the Graphlit service. Ingest anything from Slack to Gmail to podcast feeds, in addition to web crawling, into a Graphlit project - and then retrieve relevant contents from the MCP client.

Official
Featured
TypeScript
Kagi MCP Server

Kagi MCP Server

An MCP server that integrates Kagi search capabilities with Claude AI, enabling Claude to perform real-time web searches when answering questions that require up-to-date information.

Official
Featured
Python
E2B

E2B

Using MCP to run code via e2b.

Official
Featured
Neon Database

Neon Database

MCP server for interacting with Neon Management API and databases

Official
Featured
Exa Search

Exa Search

A Model Context Protocol (MCP) server lets AI assistants like Claude use the Exa AI Search API for web searches. This setup allows AI models to get real-time web information in a safe and controlled way.

Official
Featured
Qdrant Server

Qdrant Server

This repository is an example of how to create a MCP server for Qdrant, a vector search engine.

Official
Featured