I Bond Rate MCP

io.github.theluckystrike由 GitHub 账号 theluckystrike 发布v1.0.0更新于 Nov 5, 2026

Current I bond rate, what your I bond earns by issue month, and value estimates from TreasuryDirect.

已验证Streamable HTTP可网页运行金融数据与分析

概览

AI 生成的概览

远程 MCP 服务器，让助手查询 TreasuryDirect 的美国 I 系列储蓄债券当前利率、按购买月份计算的个券利率以及估值。

可以做什么
  • 查询当前 I 债券的综合利率、固定利率与半年通胀率，以及发行窗口和下次公布日期
  • 按购买月份获取某只债券的固定利率、当前 6 个月计息利率、利率调整月份和完整利率区间
  • 按购买月份和金额估算债券价值，以及持有不足 5 年扣除 3 个月利息后的赎回价值
  • 用财政部综合利率公式，对假设的固定利率和通胀率进行预测计算
  • 获取自 1998 年 9 月以来每次公布的固定利率、半年通胀率和综合利率
适用场景
适合回答现在 I 债券利率是多少、某月买入的既有债券当前赚多少、某笔持仓值多少以及赎回能拿多少这类问题。也适合做假设性利率测算，因为当前利率晚于多数模型的训练数据。
运行要求
需要一个远程 streamable HTTP 端点，无需 API 密钥、令牌或注册。README 还提到本地 npm 方式，但该包尚未发布，届时需 Node 20 或更高版本。需要能访问托管端点，获取实时利率时还需访问 TreasuryDirect。
安装前请注意
只读：不会访问你的 TreasuryDirect 账户，也不处理 EE 债券或税务。估值是按每 25 美元面额、半年复利计算的估算值，可能与财政部数值相差几分钱。个券利率表使用内置利率表，托管服务器在 TreasuryDirect 无响应时会回退到该表，结果可能滞后于实时页面；每次结果都会标明所用来源。

安装

在 SourceWeft 中

  1. 打开 控制台中的 I Bond Rate MCP，将其添加到工作区。
  2. 为需要使用其工具的对话启用该服务。

Web executable，通过 Streamable HTTP。 远程服务在工作区中配置后即可从网页运行时运行。

交给智能体安装

把这段提示词粘贴到 Claude Code、Codex、Cursor 等智能体，或 SourceWeft 对话中。智能体会读取该服务器的安装指南，先向你展示发布者、端点和登录方式，经你同意后再把它添加到你的客户端。密钥不会写进任何命令。

阅读 https://sourceweft.com/mcp/io.github.theluckystrike%2Fi-bond-rate-mcp/install.md，并按其中说明把这个 MCP 服务器接入我的客户端。修改任何配置之前，先告诉我它的发布者、端点和登录方式，等我确认。不要把 API 密钥写进命令或我会提交的文件；问我密钥应从哪里获取。

查看智能体所依据的安装指南

其他 MCP 客户端

把它添加到你客户端的 mcpServers 配置中。

{
  "mcpServers": {
    "i-bond-rate": {
      "type": "http",
      "url": "https://i-bond-rate-mcp.lipmichal.workers.dev/mcp"
    }
  }
}

README

i-bond-rate-mcp

Current I bond rate for AI assistants, and the rate your own I bond earns now. I bonds bought from November 1, 2026 to April 30, 2027 earn 5.51 percent, with a 1.40 percent fixed rate.

This is a Model Context Protocol (MCP) server. It reads the current rate from TreasuryDirect at call time and carries every rate since September 1998 from the TreasuryDirect rate chart. It needs no API key.

Tools

ToolWhat it returns
get_current_i_bond_rateComposite, fixed and semiannual inflation rate for I bonds bought now, the issue window, the next announcement date and the purchase and redemption rules.
get_i_bond_rate_for_issue_dateFor a bond bought in a given month: its fixed rate, the rate it earns in the current 6-month period, the two months its rate changes, whether it can be cashed and every rate period since issue.
estimate_i_bond_valueEstimated value for an issue month and amount, with all interest and after the 3-month penalty for bonds under 5 years.
calculate_i_bond_composite_rateThe Treasury formula for any fixed rate and semiannual inflation rate, for predictions.
get_i_bond_rate_historyEvery fixed rate and semiannual inflation rate since September 1998, newest first.

Every result has structured JSON, a one-paragraph summary, as_of, source (the TreasuryDirect page or rate chart) and more (a page on mcpstamp.com).

What it knows that your model does not

  • The November 2026 rates (5.51 percent composite, 1.40 percent fixed, 2.04 percent semiannual inflation). Treasury announced them on November 1, 2026.
  • That an existing bond does not earn the new-bond rate. It keeps its own fixed rate and gets a new inflation rate every 6 months from its issue month, so a bond bought in April 2022 earns 3.34 percent from October 2026 while a bond bought in January 2023 earns 3.75 percent until January 2027.
  • The exact rounding and the zero floor. The formula reproduces all 1,711 composite rates in the Treasury chart.

Install

Hosted (Claude.ai custom connector, ChatGPT developer mode)

Paste this URL. No token, no sign-up. It works now.

https://i-bond-rate-mcp.lipmichal.workers.dev/mcp

Claude Code

claude mcp add --transport http i-bond https://i-bond-rate-mcp.lipmichal.workers.dev/mcp

Claude Desktop

Claude Desktop adds remote servers under Settings, Connectors, Add custom connector. Paste the URL above.

Cursor

Add to ~/.cursor/mcp.json:

json
{  "mcpServers": {    "i-bond": { "url": "https://i-bond-rate-mcp.lipmichal.workers.dev/mcp" }  }}

VS Code

Add to .vscode/mcp.json:

json
{  "servers": {    "i-bond": { "type": "http", "url": "https://i-bond-rate-mcp.lipmichal.workers.dev/mcp" }  }}

Local stdio (after npm release)

The npm package is not published yet. After it is, run it locally with Node 20 or newer:

claude mcp add i-bond -- npx -y i-bond-rate-mcp

Example prompts

  • "What is the I bond rate right now?"
  • "What is the I bond fixed rate for November 2026?"
  • "I bought I bonds in April 2022. What rate are they earning now?"
  • "What is $10,000 of I bonds bought in January 2023 worth today, and what would I get if I cash them?"
  • "If May 2027 inflation is 1.5 percent and the fixed rate stays at 1.40, what would the I bond rate be?"

Data sources

Full list with fetch dates in DATA_SOURCES.md.

Limitations

  • Value is an estimate per $25 with semiannual compounding. Treasury values can differ by cents. Your TreasuryDirect account and the Savings Bond Calculator are the record.
  • Rates after April 2027 are not known until Treasury announces them on May 1, 2027. The current-rate tool reads the live page, but the per-bond schedule uses the built-in chart until this server is updated.
  • TreasuryDirect did not answer the hosted Worker on 2026-11-05, so the hosted server falls back to the built-in rate chart after a few seconds. Every result says which source it used in rate_source.
  • It does not read your TreasuryDirect account and does not handle EE bonds or taxes.

More

More MCP servers that answer questions your assistant cannot answer alone are on mcpstamp.com.

Part of the Zovo MCP collection: https://mcp.zovo.one

Built by theluckystrike.

Development

npm installnpm test                              # builds, then runs the fixture tests and an offline stdio testnode scripts/stdio-transcript.mjs     # live stdio round trip, writes .live/stdio-transcript.jsonl

License

MIT

来源：README.md，提交 c73af2b

工具

5

get_current_i_bond_rate

Get current I bond rate

Current Series I savings bond composite rate, fixed rate and semiannual inflation rate for new purchases, read at call time from the TreasuryDirect "I bonds interest rates" page with the built-in rate chart as fallback. November 2026 to April 2027: 5.51 percent with a 1.40 percent fixed rate. Also returns the next announcement date and the $10,000 limit, 12-month hold and 3-month penalty rules.

无需输入参数。

get_i_bond_rate_for_issue_date

Get I bond rate for an issue date

For an I bond bought in a given month: its fixed rate, the composite rate it earns in the current (or given) 6-month period, the months its rate changes, whether it can be cashed and the penalty, and every rate period since issue. Computed from the TreasuryDirect rate chart effective November 1, 2026.

输入参数as_of_monthissue_month必填

estimate_i_bond_value

Estimate I bond value

Estimate what I bonds are worth for an issue month and purchase amount at the start of a month: value with all interest and the redemption value after the 3-month penalty for bonds under 5 years. Uses semiannual compounding per $25 with the TreasuryDirect rates. An estimate; Treasury values can differ by cents.

输入参数amount必填as_of_monthissue_month必填

calculate_i_bond_composite_rate

Calculate I bond composite rate

Apply the Treasury formula fixed + 2 x semiannual inflation + fixed x semiannual inflation, rounded to 0.01 percent with a floor of zero. Use it for rate predictions.

输入参数fixed_rate必填semiannual_inflation_rate必填

get_i_bond_rate_history

Get I bond rate history

Fixed rate for new bonds, semiannual inflation rate and composite rate for every May and November announcement since September 1998, newest first, from the TreasuryDirect rate chart.

输入参数limit

版本历史

1
  1. v1.0.0最新Nov 5, 2026

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