Due Date Calculation for AI Agents
The tool
The API calculates current pregnancy progress, trimesters, important milestones, and time remaining until due date with week-by-week breakdowns.
Once your client is connected to the VerveContext MCP server, this appears in its tool list as DueDateCalculationforAIAgents. It is read-only and open-world: it fetches, it never mutates anything on your side, so most clients will call it without asking you to confirm.
{
"name": "DueDateCalculationforAIAgents",
"arguments": {
"last_period": "2025-06-01"
}
}What that looks like in a conversation
You don't name the tool — the model picks it. Asking about 2025-06-01 in the terms this source covers is enough for it to reach for DueDateCalculationforAIAgents on its own.
Connecting
One server URL covers every source in the catalog, including this one. Authorization is OAuth — the client opens a browser once and there is no key to paste into a config file.
{
"mcpServers": {
"vervecontext": {
"url": "https://api.vervecontext.com/v1/mcp"
}
}
}https://api.vervecontext.com/v1/mcpPer-client setup — Claude Desktop, Cursor, VS Code, ChatGPT — is on the MCP setup page.
Arguments
These are the properties on the tool's inputSchema, so a well-behaved client validates them before the call is made.
| Argument | Type | Example | Description |
|---|---|---|---|
last_periodRequired | string | 2025-06-01 | First day of last menstrual period (YYYY-MM-DD) |
What the model gets back
The result carries a structuredContent object matching the tool's declared outputSchema, so a client can read fields without parsing prose. status is "ok" on success and error is null; a null field means the value wasn't available for that input, not that the call failed.
{
"status": "ok",
"error": null,
"data": {
"calculation_method": "last_period",
"last_period_date": "2024-01-01",
"estimated_conception_date": "2024-01-15",
"due_date": "2024-10-07",
"current_progress": {
"days_pregnant": 715,
"weeks_pregnant": 102,
"days_into_week": 1,
"formatted": "102 weeks, 1 days",
"trimester": 3,
"percentage_complete": 255.36
},
"time_until_due": {
"days": 0,
"weeks": 0,
"days_extra": 0,
"formatted": "Past due date",
"is_overdue": true
},
"upcoming_milestones": [],
"important_dates": {
"end_first_trimester": "2024-04-01",
"end_second_trimester": "2024-07-08",
"full_term_begins": "2024-09-16"
},
"disclaimer": "This is an estimate only. Due dates can vary. Consult your healthcare provider for medical advice."
}
}Fields
| Field | Type | Example | Description |
|---|---|---|---|
calculation_method | string | Method used for calculation: last_period or conception_date | |
last_period_datePremium | string | Estimated first day of last menstrual period | |
estimated_conception_datePremium | string | Conception date provided as input | |
due_date | string | Estimated delivery date in ISO format | |
current_progress | object | How far along the pregnancy is today, in days and weeks | |
└ current_progress.days_pregnantPremium | number | Total number of days pregnant | |
└ current_progress.weeks_pregnantPremium | number | Number of complete weeks of pregnancy | |
└ current_progress.days_into_weekPremium | number | Additional days beyond complete weeks | |
└ current_progress.formattedPremium | string | Human-readable pregnancy duration with weeks and days | |
└ current_progress.trimesterPremium | number | Current trimester number: 1, 2, or 3 | |
└ current_progress.percentage_completePremium | number | Pregnancy completion percentage relative to due date | |
time_until_due | object | How long until the due date, with a formatted summary | |
└ time_until_due.daysPremium | number | Complete days remaining until due date | |
└ time_until_due.weeksPremium | number | Complete weeks remaining until due date | |
└ time_until_due.days_extraPremium | number | Additional days beyond complete weeks remaining | |
└ time_until_due.formattedPremium | string | Human-readable time remaining until delivery | |
└ time_until_due.is_overduePremium | boolean | Whether pregnancy has passed the due date | |
upcoming_milestonesPremium | array | Array of upcoming pregnancy milestones and dates | |
important_dates | object | Key milestones: the end of each trimester and viability | |
└ important_dates.end_first_trimesterPremium | string | Estimated end date of first trimester | |
└ important_dates.end_second_trimesterPremium | string | Estimated end date of second trimester | |
└ important_dates.full_term_beginsPremium | string | Date when pregnancy reaches full term status | |
disclaimer | string | Medical disclaimer about estimated due dates |
Why ground on it
A model can produce something that looks like this answer from its training data, and be confidently out of date or simply wrong. This source returns the current value with a shape you can check, which is the difference between an answer you can cite and one you have to hedge.
Point an evaluation at calculation_method: it is the field most worth pinning a claim to, and it is either present and current or absent — never plausibly invented.
Failure modes
Errors come back as tool errors with a sentence the model can act on, not a bare status code.
| Status | What it means |
|---|---|
400 / 422 | The arguments didn't validate. The message names the offending one. |
401 | The OAuth session is invalid or expired — reconnect the server. |
403 | Out of credits. Not a bad key — the month's allowance is spent. |
404 | This source isn't part of VerveContext. Check the catalog. |
429 | Brief rate limit. Retrying after a moment succeeds. |
Other ways to use Due Date Calculation for AI Agents
Set up Due Date Calculation for AI Agents on VerveContext, or reach the same source a different way. Your VerveContext account and credits work on all of them — one key, one balance.
Frequently asked questions
Do I have to tell the agent to use DueDateCalculationforAIAgents?
No. The tool's name and description are in the model's context once the server is connected, so it selects the tool when the question calls for it. Naming it explicitly works too and is useful when you want to force the call.
Does connecting the server expose every tool at once?
Yes — one connection lists the whole VerveContext catalog. Clients with a tool budget can usually filter the list; the credit cost is per call, so an unused tool costs nothing.
What does a call cost?
1 credit each time the tool actually runs. A model that reasons about the tool without calling it costs nothing.
Is there a REST version of this?
Yes — the same source is available as a plain HTTPS endpoint on APIVerve, linked above. Same data, same credits, same account.