SpreadBench NCSX-IS — MCP server

Official Model Context Protocol server for SpreadBench NCSX-IS, an issuance-spread benchmark for AI-infrastructure (Neocloud) bonds.

What NCSX-IS measures. For each constituent bond, the coupon minus the US Treasury yield of matching tenor on that bond's pricing date, weighted by face value. It is a point-in-time issuance spread — event-driven, no daily frequency, and not a traded CDS level or a rating. SpreadBench publishes no credit ratings and no investment advice.

Live data: https://spreadbench.com · Methodology + DOI: https://spreadbench.com/methodology.html · JSON API: https://spreadbench.com/api.html

Two ways to connect

1. Remote (streamable-http, nothing to install)

{
  "mcpServers": {
    "ncsx": {
      "type": "streamable-http",
      "url": "https://spreadbench.com/mcp"
    }
  }
}

Free, no API key, no signup.

2. Local (stdio, same tool set)

npm install -g github:BrianTian818/spreadbench-ncsx-mcp
# or, without npm registry:
npm install -g https://spreadbench.com/download/ncsx-mcp-0.3.0.tgz

{
  "mcpServers": {
    "ncsx": { "command": "ncsx-mcp" }
  }
}

Both transports share one tool definition file (tools.js), so they never drift apart.

Related MCP server: wrds-mcp

Tools

Fourteen read-only tools, all keyless. Every tool declares readOnlyHint: true / destructiveHint: false, so clients do not prompt for write permission.

Three names from the demo-era server — ncsx_levels, ncsx_attribution, ncsx_weekly — are not listed any more, but still answer if an old client calls them: they return a structured retirement notice rather than an error.

Read data_status before you quote anything

Every payload carries a data_status field. This is the single most important field in the schema:

If a tool returns status: "retired", the endpoint was withdrawn — read the replacement field and move on. Nothing in this server will silently hand you demo numbers.

Example prompts

• "What is the current NCSX-IS spread, and how does the unsecured cohort differ from the secured one?"

• "Which CoreWeave bonds are in the index and what spread did each price at?"

• "Compare NCSX-IS against the US high-yield OAS over the last 90 days."

• "Which Treasury tenors does the index lean on most?"

• "Is the NCSX-IS level consistent with the latest SEC N-PORT marks?"

• "A $1.5bn 5-year note at 8.25% — where does that price relative to this market, and what would it do to NCSX-IS?"

• "How did NCSX-IS get from 517.7bp to 432.3bp, and which issuer pulled it the most?"

Conventions

• Identifier: constituents are identified by issuer + coupon + maturity. They do not carry CUSIPs — do not query by CUSIP.

• Units: spreads in basis points over the Treasury at pricing. Notionals in USD millions.

• Frequency: event-driven. There is no T+1 update and no daily change field.

• Reproducibility: every number is derived from public filings (SEC EDGAR) and the US Treasury par-yield curve. The methodology page states the exact formula and the interpolation rule.

Notes on naming

Older versions of this server exposed Composite / HY / IG tiers and 90-day daily series. Those came from a demo dataset and were withdrawn on 2026-11-04 in favour of the issuance-spread methodology (v0.2.0-real). The three retired names listed above remain callable only so that old clients receive an explicit notice instead of an error; they are hidden from tools/list.

Directory listings

This server is listed in the official MCP Registry as com.spreadbench/ncsx, and is indexed by Glama (A tier) and brick.blue. glama.json in this repo claims the listing for its maintainer.

License

MIT. Data is published for research and citation; SpreadBench does not provide credit ratings or investment advice.