Mostly Right Docs

Mostly Right gives you public data with clear sources and timestamps. Historical and live methods return the same core fields. Every row names its source.

Install

Python 3.11+:

pip install mostlyrightmd

TypeScript on Node 20+:

pnpm add mostlyright

One install includes the weather, markets, economy, and finance domains. Your subscription’s API key retrieves the current source manifest. The SDK then fetches data directly from each public source.

export MOSTLYRIGHT_API_KEY="..."

Get your key (USD 29/month) or read the credentials guide for source-specific keys.

Compare shared live and archive fields

from mostlyright import weather

live = await weather.live.latest("KNYC")
historical = weather.observations(
    "KNYC", "2025-01-15", "2025-01-15",
    return_type="list",
)[-1]

for label, row in (("live", live), ("historical", historical)):
    print(label, row["event_time_utc"], row["temp_f"], row["source"])

import { weather } from "mostlyright";

const live = await weather.latest("KNYC");
const { rows } = await weather.observations(
  "KNYC", "2025-01-15", "2025-01-15",
);
const historical = rows.at(-1);

console.log(
  "live",
  live.event_time_utc,
  live.temp_f?.toFixed(1),
  live.source,
);
console.log(
  "historical",
  historical?.event_time_utc,
  historical?.temp_f?.toFixed(1),
  historical?.source,
);

Both rows expose the same timestamp, temperature, and source fields. Their values differ because one row is current and the other is historical. Continue to the Quickstart to compare archive and live reads and fetch official daily reports.

Choose what to read next

Building a model? Follow Build a point-in-time research table for explicit cutoff filters and joins.
Need raw reports? Use Weather observations for per-report archive rows.
Connecting markets? See Kalshi & Polymarket for resolvers, discovery, settlement, and venue history.
Building an agent? Point it at /llms.txt for the machine-readable product and docs index.

Timing and source checks

Temporal controls: filter or check data against a cutoff when the source has a reliable availability timestamp.
Source checks: every frame names the feed that produced it, so a different live source can raise an error.

Read Temporal safety for cutoff checks and Data sources for source tags and merge rules.

Domains

Weather: live METAR, observations, forecasts, daily summaries, and satellite measurements
Markets: Kalshi and Polymarket resolvers, discovery, settlement, and history
Economy: CPI, PPI, payrolls, GDP, jobless claims, and Fed decisions with first-print vintages
Finance: earnings-call transcripts and earnings-mention resolution

Sports and politics are next.