Japanese FX gotobi (五十日) date lookup — next occurrence, with holiday adjustments through 2099.
What it does
The Gotobi Calendar API is a specialized x402-payable endpoint that returns the next Japanese gotobi (五十日) date relative to today. Gotobi dates are the 5th, 10th, 15th, 20th, 25th, and last day of each month — key settlement dates in Japanese foreign exchange markets when USD/JPY demand typically spikes. The `/gotobi/next` endpoint returns today's date, the next gotobi date, and the number of days until it, with automatic adjustment for Japanese public holidays (shifted to the preceding business day). Coverage extends through 2099.
The API is part of a broader Gotobi Calendar service hosted at gotobi.hugen.tokyo that also offers endpoints for checking whether today is a gotobi date (`/gotobi/today`), listing all gotobi dates in a given month (`/gotobi/dates?month=YYYY-MM`), and querying Japanese public holidays (`/gotobi/holidays`, `/gotobi/holidays/today`, `/gotobi/holidays/next`). All paid endpoints cost $0.01 USDC per call on Base via the x402 protocol. Alternative access is available through an MCP gateway, API key with free trial credit, or the `x402-pay` Python SDK.
The response schema for `/gotobi/next` includes `today` (current date string), `next_gotobi_date` (the upcoming gotobi date string), `days_until` (integer countdown), and a human-readable `description` field. The OpenAPI 3.1 spec is fully published with typed schemas for all endpoints.
Capabilities
Use cases
- —Algorithmic FX trading strategies that need to anticipate USD/JPY demand spikes on gotobi dates
- —Scheduling or alerting systems that track Japanese financial settlement cycles
- —Portfolio management tools that factor in Japanese market calendar effects
- —AI agents that need structured calendar data for Japanese FX market analysis
Fit
Best for
- —FX traders and quant strategies focused on USD/JPY gotobi effects
- —Automated trading bots needing machine-readable Japanese settlement calendars
- —Financial data pipelines requiring holiday-adjusted gotobi dates through 2099
Not for
- —General-purpose world holiday calendars (only covers Japanese public holidays relevant to gotobi)
- —Real-time FX price data or trade execution
- —Non-financial calendar scheduling needs
Quick start
# Using x402-pay Python SDK (no wallet setup needed)
pip install x402-pay
import x402_pay
resp = x402_pay.get('https://gotobi.hugen.tokyo/gotobi/next')
print(resp.json())Example
Response
{
"today": "2026-02-19",
"days_until": 1,
"description": "The next gotobi date is 2026-02-20, which is 1 day away.",
"next_gotobi_date": "2026-02-20"
}Endpoint
Quality
Full OpenAPI 3.1 schema with typed response models is published. The x402 challenge is live and returns a sample response confirming the endpoint works. Price is clearly stated ($0.01 USDC on Base). Docs are auto-generated Swagger; no dedicated prose documentation or usage examples beyond the SDK one-liner, which slightly limits completeness.
Warnings
- —Root URL returns 404 — no landing page; documentation is only at /docs (Swagger UI)
- —No dedicated pricing page; price is only visible in the x402 challenge header
- —The description field in responses is inferred from the sample in the x402 challenge; exact wording may vary
Citations
- —The API describes itself as 'The only programmatic source for Japanese FX gotobi (五十日) dates' with coverage through 2099https://gotobi.hugen.tokyo/docs
- —The /gotobi/next endpoint returns today, next_gotobi_date, days_until, and description fieldshttps://gotobi.hugen.tokyo/docs
- —Payment is $0.01 USDC on Base via x402https://gotobi.hugen.tokyo/gotobi/next
- —Alternative access via MCP gateway, API key, or x402-pay Python SDKhttps://gotobi.hugen.tokyo/gotobi/next
- —Sample response shows today=2026-02-19, next_gotobi_date=2026-02-20, days_until=1https://gotobi.hugen.tokyo/gotobi/next