I Bond Rate MCP

io.github.theluckystrike/i-bond-rate-mcp · v1.0.0 · other

I Bond Rate MCP is healthy: it completed an MCP handshake in 650 ms and exposes 5 tools.

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

Endpoint: https://i-bond-rate-mcp.lipmichal.workers.dev/mcp (streamable-http)

Facts

Checked (UTC)	Status	Latency	Error
2026-11-05T15:05:41.512Z	Healthy	650

`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 r
`get_i_bond_rate_for_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, 202
`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 diff
`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.
`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.