# CrashTestYourStrategy — MCP Server

**Remote MCP server for portfolio & trading-strategy stress diagnostics.**
Free tier — no key, no signup. Descriptive, never advisory.

```
https://mcp.crashtestyourstrategy.ai/mcp
```

[![smithery badge](https://smithery.ai/badge/nobbefrederic/crashtestyourstrategy)](https://smithery.ai/servers/nobbefrederic/crashtestyourstrategy)

Listed in the [official MCP registry](https://registry.modelcontextprotocol.io) as
`io.github.fnobbe/crashtestyourstrategy`. This repository is the public server card —
the service itself is closed-source; everything an agent (or a reviewer) needs to
verify behaviour is linked below.

## Quick start

Claude Code:

```bash
claude mcp add --transport http ctys https://mcp.crashtestyourstrategy.ai/mcp
```

Generic MCP client config (streamable HTTP):

```json
{
  "mcpServers": {
    "ctys": {
      "type": "streamable-http",
      "url": "https://mcp.crashtestyourstrategy.ai/mcp"
    }
  }
}
```

claude.ai: *Settings → Connectors → Add custom connector* with the URL above.

The free tier is rate-limited per IP (30 req/min). No account, no key.

## What it does

An open diagnostics layer that confronts a proposed portfolio or trading strategy
with the failure modes an optimistic backtest ignores — hedge breaks (the 2022
stock-bond case), sequence-of-returns risk, regime blind spots, deflated Sharpe.

**Free tier (16 tools)**

| Group | Tools |
|---|---|
| Portfolio | `portfolio_stress_test` (multi-asset stress across baseline / risk-off / rate-shock regimes, hedge-break detection, full drawdown distribution) · `portfolio_compare` · `factor_decomposition` · `ips_gate` (hard gate vs an Investment Policy Statement, breach probability not median path) · `long_horizon_stress` (multi-year savings/withdrawal plans, ruin probabilities) |
| Strategy | `run_stress_test` · `challenge_strategy` · `backtest_integrity` (deflated Sharpe + which crisis regimes the backtest window missed) |
| Regimes | `regime_outlook` (model-conditional BULL/SIDEWAYS/BEAR/CRISIS probabilities at 5/21 trading days — preregistered, out-of-sample validated, refreshed daily) · `market_regime_map` (18-category cross-asset map) · `describe_regime` · `find_similar_regime` |
| Record & catalog | `list_investment_theses` · `get_investment_thesis` · `get_dossier` (citable audit trail of prior calls) · `submit_feedback` |

**Full tier** (token via [contact](https://crashtestyourstrategy.com/contact)):
`tier2_stress_test` (stress **any** ticker with auto-calibration + realism gate),
`build_portfolio`, `portfolio_frontier`.

## Response contract

Every response is a versioned envelope (`ctys-agent-v1` family) carrying:

- `grounding_summary` — a risk-focused factual statement of the omitted tail
- `revision_required` — a gate-capable signal (never a directive)
- `methodological_limitations` — required disclosure of what the diagnostic does NOT establish
- `data_through` / `data_staleness_days` — self-reported data freshness (EOD, refreshed daily)

`validation://` resources expose the realism trust layer: 18 measured stylized facts
per asset vs historical reference bands — the falsifiability surface. Recompute
locally; trust by independent reproduction.

## Scope & compliance

Model-based scenario simulation. Descriptive, never advisory: no suitability,
timing, or ranking claim is made or implied — the agent decides what "suitable"
means. Out-of-sample limits are disclosed, not hidden (e.g. the GFC hedge-behaviour
test failed and ships as a documented limitation).

## Links

- Capability declaration: <https://crashtestyourstrategy.com/interop> (JSON: [/interop.json](https://crashtestyourstrategy.com/interop.json))
- Methodology: <https://crashtestyourstrategy.com/methodology>
- Weekly market-regime outlook (citable, auto-generated): <https://crashtestyourstrategy.com/outlook>
- Failure-mode ontology: <https://crashtestyourstrategy.com/ontology>
- llms.txt: <https://crashtestyourstrategy.com/llms.txt>
- Smithery listing: <https://smithery.ai/servers/nobbefrederic/crashtestyourstrategy>

Maintainer: [@fnobbe](https://github.com/fnobbe) · Operator contact: <https://crashtestyourstrategy.com/contact>