MCP servers
MCP server for macroeconomic data (vintage-aware)
Ask most macro tools for GDP in a past quarter and you get today's revised number. An agent then states that figure as what was known at the time, and the answer is confidently wrong in a way that is nearly impossible to notice downstream.
This MCP server makes the as-of date a first-class argument. The agent passes the date it is reasoning about, and the tool returns the vintage that was current then — the first print if the question predates the revision, the revised value if it does not. Release calendars are exposed as their own tool, so an agent can check whether a number even existed on the date in question before asserting anything about it.
The design goal is narrow and specific: make it structurally difficult for a language model to time-travel, without requiring the model to understand revision mechanics.
hindcast — session
previewhindcast> what was the latest published inflation print on this date?
→ tool: macro_series { series:"...", as_of:"..." }
✓ the value that was current on that date, with its release date
source: statistical agency releases, every vintage retained
What's covered
- Tool: series lookup with a required as-of date argument
- Tool: revision history for a single observation over time
- Tool: release calendar — what was scheduled and what had published
- First prints retained separately from later revisions
- US and Brazilian series on one vintage model
- Responses name the release the value came from
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Questions
What if I want the latest value, not a vintage?
Ask for today's date. The vintage model is a superset of the usual behavior — the difference is that the historical question becomes answerable rather than being silently approximated.
Does this stop an agent from using future information?
It removes the easiest path to it. An agent can still misuse a tool, but it can no longer get a revised figure while believing it asked for a historical one, which is where most of this error actually comes from.
Related
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