OpenAI plugin publication
Publishing the MCP Registry record alone does not attach Calcgrid to ChatGPT or Codex. Create a remote-MCP plugin in the OpenAI plugin submission portal with https://tttkmbb.com/mcp, scan the tools, complete review and then publish it to the universal Plugins Directory.
Listing draft
- Name: Calcgrid — Deterministic Calculators
- Short description: Use deterministic calculators plus official China/UK working-day and pinned IANA time-zone data.
- Website: https://tttkmbb.com
- Support: https://tttkmbb.com/docs/support
- Privacy: https://tttkmbb.com/docs/privacy
- Terms: https://tttkmbb.com/docs/terms
- Authentication: none
- MCP server: https://tttkmbb.com/mcp
Starter prompts
- Is Sunday 2026-01-04 an official working day in mainland China?
- What date is five official China working days after 2026-09-24?
- Is 28 December 2026 a working day in England and Wales, or the Boxing Day substitute holiday?
- Add two Scottish working days to 12 June 2026 using official bank holidays.
- Convert 2030-10-01 to the Chinese lunar calendar and identify a leap month if present.
- List all 24 solar terms for 2031 in Asia/Shanghai, including the exact instant of 立春.
- Resolve 2026-11-01 01:30 America/New_York and return both valid UTC instants.
- List every 2026 clock transition in Australia/Adelaide with offsets before and after.
- Convert 2028-07-15 09:30 America/New_York to Australia/Adelaide using that date's DST rules.
- Calculate the payment and total interest on a 420000 fixed-rate loan at 6.15% for 25 years.
- Compare a 300000 loan at 6% for 30 years with 3000 in fees against 5.5% for 15 years with 5000 in fees.
Positive review tests
| Prompt | Expected tool | Expected result |
|---|---|---|
| Is 2026-01-04 an official working day in mainland China? | check_china_working_day | Adjusted Sunday workday with State Council source id |
| Add five official China working days to 2026-09-24. | add_china_working_days | 2026-10-09 with skipped holidays and dataset version |
| Is 28 December 2026 a working day in England and Wales? | check_uk_working_day | Boxing Day substitute holiday with GOV.UK source hash |
| Add two Scottish working days to 12 June 2026. | add_uk_working_days | 2026-06-17 after weekend and official bank holiday |
| What lunar date is 2027-02-06? | convert_solar_to_lunar | Completed lunar conversion with formula/source metadata |
| Convert lunar 2028 month 8 day 15 to Gregorian. | convert_lunar_to_solar | Completed Gregorian date |
| List the 24 solar terms for 2029 in UTC+8. | list_solar_terms | 24 dated terms including 立春 |
| Resolve 2026-11-01 01:30 in New York. | resolve_local_time | Two UTC candidates, offsets and tzdb provenance |
| List Adelaide clock changes during 2026. | list_time_zone_transitions | Two transition records with before/after offsets |
| Convert 2028-07-15 09:30 New York to Adelaide. | convert_time_zone | Date-aware offsets and converted timestamp |
| Compare the two fixed loan offers in starter prompt five. | compare_loans | Both payments, interest, fees and lifetime-cost difference |
Negative review tests
| Prompt | Expected behavior |
|---|---|
| What is today's best mortgage rate in Canada? | Do not call; Calcgrid has no live lender data |
| Will it rain in Adelaide tomorrow? | Do not call; Calcgrid is not a weather forecast provider |
| Tell me which loan I must choose. | May calculate supplied scenarios but must not give personalised financial advice or invent missing offers |
Domain verification
Set the Worker secret OPENAI_APPS_CHALLENGE_TOKEN to the exact token generated by the portal. Calcgrid serves only that token at https://tttkmbb.com/.well-known/openai-apps-challenge; without the secret the endpoint returns 404. After deploying the token, run Scan Tools, verify all annotations and schemas, execute the tests above, and submit the reviewed snapshot.
The publisher must still complete OpenAI developer or business identity verification and provide a working publisher contact before submission. Current tool count: 53 advertised read-only tools covering 538 calculators.
Markdown source: /docs/openai-plugin.md