Hosted manifest
The SDK resolves every data source through the hosted manifest: the maintained record of where public data lives. Your subscription’s API key is what connects the SDK to it; without a key the SDK does not resolve sources.
What the manifest is
Section titled “What the manifest is”Public data does not sit still: agencies rename endpoints, move hosts, and change formats. The manifest is the catalog the SDK consults to know where each source currently lives and how its address has changed over time, including transition dates and advisories. It is served whole from api.mostlyright.md/api/manifest, so requests reveal nothing about which sources interest you.
The key requirement
Section titled “The key requirement”Install the Python SDK from PyPI and the TypeScript SDK from npm; running either requires an active subscription’s API key. Without a configured MOSTLYRIGHT_API_KEY, the SDK raises ApiKeyRequiredError and resolves nothing; there is no keyless mode.
Getting a key
Section titled “Getting a key”Subscribe at app.mostlyright.md: USD 29/month, one tier. Sign in with Google or GitHub, and mint your API key after checkout. The key is shown once; it can be rotated or revoked from the app at any time.
Using the key
Section titled “Using the key”export MOSTLYRIGHT_API_KEY="mr_live_..."That is the whole setup. Both SDKs pick the variable up automatically; no code changes are needed. The same variable also authenticates the separate hosted weather and finance transports described in Credentials.
If a subscription lapses
Section titled “If a subscription lapses”The manifest endpoint returns 402 and the SDK stops resolving sources until the subscription is active again. A 402 in your logs is a billing state, not an outage; reactivating the subscription restores resolution with the same key.