PreReason

@prereason/mcp

[Prereason](https://www.prereason.com) first. Then answer.

Financial market context for AI agents, with listed companies' results: www.prereason.com/agents.md

Docs · Briefings · Company briefings · Pricing · Get a key

Ask your AI where Treasury yields are. On its own, it reaches for a search result or a raw series and works out the rest by itself. When it prereasons, one get_context call brings back the context already worked out: the 30 year yield at 5.67% on 2026-10-07, the highest reading on the US Treasury's daily par yield curve since July 2001.

Why prereason?

• The analysis, and the data behind it. Each briefing arrives with the reading done: the trend over several windows, where a value sits in its own history, a company's rank among its peers and, where read, its own guidance.
• Every figure dated, every source named. Your agent can say when a number is from and where it came from.
• One call, a whole briefing. A briefing gathers the series a question needs, so the turns go to the answer rather than to lookups.
• The markets in one place, among them rates and Treasuries, the Fed, FX, commodities, macro, listed companies across several markets, and Bitcoin.
• It describes; it never advises. Briefings say what the data shows. They never say what to buy, sell or hold.
• Quick to set up. One block of config for Claude, Cursor, Codex or VS Code, through the npm bridge or the remote server. The catalogue tools need no key; for the rest, the bridge gives you one link to approve in your browser and the key arrives in the running session; the remote server takes your API key as a header.

What it covers

PreReason gives an AI agent market context it can reason with. Ask what a listed company reported, where Treasury yields stand or what the Federal Reserve decided, and one call returns a briefing reasoned in advance: the figures with their dates and sources, a one line reading, trend direction over several windows, confidence scores, percentile ranks and correlations, and in the deeper briefings a regime label and a plain language narrative. Briefings span asset classes and regions, among them listed companies built from each company's own reports and filings, macro and the economic calendar, interest rates and Treasury yields, bonds, currencies, commodities and energy, and Bitcoin. The set grows as markets and asset classes are added; list_briefings and list_metrics always return the current one. Each briefing carries the figures behind its readings, every figure is dated, and every briefing names its sources. It is served over MCP (a remote server and an npm bridge) and over REST, as Markdown or JSON. An AI agent starts at https://www.prereason.com/agents.md, which says how to connect, which briefings it can read and how to answer from them.

Quick Start

Option 1: Claude Desktop, no key needed

Requires [Node.js 18+](https://nodejs.org), and nothing else: the bridge has no dependencies.

Add this to claude_desktop_config.json and restart Claude Desktop:

{

"mcpServers": { "prereason": { "command": "npx", "args": ["-y", "@prereason/mcp"], "env": { "PREREASON_CLIENT": "claude-desktop" } } } }

The catalogue tools work at once. To connect your account, tell Claude "connect me to PreReason", or ask for any briefing: either way Claude shows one link, https://www.prereason.com/claim/PR-XXXX-XXXX. Open it, sign in or create an account, click Approve. The key arrives in the bridge on its own, is saved to ~/.prereason/credentials.json, and is never shown; ask Claude whether PreReason is connected and it names your plan. Nothing is created in your account until you click Approve, and the link is asked for when you need it, so it never runs out while Claude sits open. If your account already holds as many API keys as it allows, the answer says so instead of looping: revoke a key under Settings on prereason.com, then ask to connect again, or set PREREASON_API_KEY to a key you already have.

Config file location:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

Already have a key? Add it to the env block as "PREREASON_API_KEY": "pr_live_..." and the bridge never asks.

Option 2: Direct HTTP with an API key (Claude Code, Cursor, Windsurf, Codex, Gemini CLI, VS Code, scripts)

Clients that hold their own config can call the endpoint directly, with the key as a header:

# Claude Code

claude mcp add --transport http prereason https://api.prereason.com/api/mcp --header "Authorization: Bearer YOUR_API_KEY"

{

"mcpServers": { "prereason": { "type": "http", "url": "https://api.prereason.com/api/mcp", "headers": { "Authorization": "Bearer YOUR_API_KEY" } } } }

Windsurf uses serverUrl instead of url; Gemini CLI uses httpUrl; Codex uses url plus bearer_token_env_var in config.toml. No key yet? Point the client at the endpoint without a header to browse the catalogue, then create a key on the website (below) and add the header.

Option 3: Claude.ai and Claude Desktop custom connector

1. In Claude, open Customize, then Connectors, then "+ Add", then Add custom connector.
2. Name it PreReason and give the address https://api.prereason.com/api/mcp.
3. Choose Sign in now, even where Claude marks No sign-in as Detected.
4. Click Add, then Allow on the PreReason screen. No account yet? Make one there.
5. Then, in a new chat, ask: "What are rates, liquidity and the dollar doing today?"

Claude's Free plan allows one custom connector at a time. On a Claude Team or Enterprise plan, an owner adds connectors for the organization, then each person clicks Connect.

Get an API Key

Three ways. The hosted server never hands out a key inside a session and never asks for one.

Through this bridge. Run it with no key set: when you ask your assistant to connect PreReason, or an answer needs a key, it asks PreReason for access on your behalf and shows one approve_url, in its log and in the answer. Open it, sign in or create your account, click Approve, and the bridge saves the key, attached to your account and named Agent: .

From code, for an agent with no browser. POST https://api.prereason.com/api/agent/claims (no auth), show the human the approve_url, then poll GET https://api.prereason.com/api/agent/claims/{claim_code} with Authorization: Bearer until status is approved. Docs: prereason.com/docs#agent-access.

On the website. Sign up at prereason.com/signup, then Dashboard > Settings > API Keys. Keys start with pr_live_.

MCP Tools

The npm bridge and the Claude Desktop extension add one tool of their own, connect_account, which the bridge answers itself and the remote server does not offer: with no key yet it returns the one link to approve, and once approved it says the account is connected and on which plan. It never shows a key and never asks for one.

Market Briefings

| bonds.full | Who holds US Treasuries: foreign investors, primary dealers and speculators, each against its own history, with the Fed's own Treasury holdings, debt held by the public, the largest foreign holders, what would change each reading and the next reports