The Quesen engine handles risk decisions for autonomous agents. A vulnerability in the engine — including any deterministic-decision leak, credential leak, or rate-limit bypass — has downstream financial consequences for every integrator.

Please do NOT open a public GitHub issue for security vulnerabilities.

Instead, email shinque03@gmail.com with the subject prefix [SECURITY]. Include:

• A description of the vulnerability.
• Steps to reproduce (against https://web-production-30ab5.up.railway.app or a local self-hosted deployment).
• Any proof-of-concept code or curl invocations.
• The impact you believe the vulnerability has.
• Your GitHub handle (optional, for credit).

We will acknowledge receipt within 72 hours and provide an initial assessment within 7 days. Critical vulnerabilities affecting production will be triaged immediately.

In scope for security reports:

• The production API at https://web-production-30ab5.up.railway.app.
• The MCP endpoint at https://web-production-30ab5.up.railway.app/mcp.
• The ASP/1.0 protocol implementation (POST /asp/quotes, POST /asp/redeem, GET /asp/providers, HTTP 402 challenge on /validate).
• The published SDKs (quesen-sdk for Python and JS/TS, quesen-langchain, quesen-crewai, quesen-autogen).
• Any documented integration example in this repository.

Out of scope:

• Rate-limit findings that only affect a self-issued key.
• Denial-of-service via traffic volume.
• Findings that require an already-compromised host or already-leaked API key.
• Any issue in a third-party service Quesen integrates with (Stripe, Coinbase Commerce, Railway, GitHub, PyPI, npm) — report those directly to the vendor.

Quesen's Agent Settlement Protocol (ASP/1.0) uses HMAC-SHA256 in a canonical JSON envelope. If you can:

• Produce a valid signature without the shared secret,
• Replay a redeemed quote,
• Bypass EIP-3009 authorization on the USDC-on-Base adapter,

please report it. These claims are constitutional.

Quesen advertises that /validate is deterministic — same inputs and same engine_version produce bit-identical outputs. If you can produce a counter-example, that is a security-grade defect (an integrator's audit trail depends on it). Please report it.

We follow a coordinated-disclosure policy. After a fix is deployed to production and integrators have had a reasonable time to update, the vulnerability will be published in the engine repository's changelog (which is reflected here as a summary entry in CHANGELOG.md).