> ## Documentation Index
> Fetch the complete documentation index at: https://docs.quantoraresearch.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Sources and rights

> Where the data comes from, and what may be redistributed.

75 sources feed the API. They are not equal, and the differences are stated on every
row rather than averaged away.

## The hierarchy

`sourceTier` ranks publishers. Where several carry the same series, the higher tier
wins and the others are marked `preferredForFactor: false`.

| Tier                      | Who                               | Example                       |
| ------------------------- | --------------------------------- | ----------------------------- |
| `central_bank`            | Central banks                     | Federal Reserve, ECB, SNB     |
| `official_national`       | National statistical offices      | BLS, ONS, Destatis            |
| `official_supranational`  | International compilers           | OECD, Eurostat, BIS, IMF      |
| `financialdatapi_derived` | Computed by us from public inputs | Real rates, curve spreads     |
| `market_data`             | Market data vendors               | Exchange and vendor feeds     |
| `world_bank_fallback`     | Annual World Bank series          | Countries with no live source |
| `news`                    | News derived                      | Sentiment and event flags     |

National sources are preferred over harmonised international copies of the same
series, because the compiling agency publishes first and revises first. Pass
`?sources=all` to receive every provider for a period rather than the preferred one.

## Rights

Some feeds are licensed to us on terms that do not permit redistribution. Those rows
are served with metadata but without a value, and say so, rather than failing in a way
you would have to guess at.

This is why an endpoint can return a row with a null value and a 200 status. The
series exists, its shape is real, and the number cannot be passed on.

<Note>
  Rights are a property of the **feed**, not of your plan. No tier unlocks a value we do
  not have the right to redistribute.
</Note>

Where a source permits display but not bulk redistribution, the row is available
through the point-in-time endpoints and excluded from bulk sync.

## Attribution

Every row carries `attribution`, the publisher's own preferred credit line, and
`sourceUrl`, a link to the release.

Several sources require that credit line to be displayed wherever the figure is shown.
Carrying `attribution` through to your UI is the simplest way to stay compliant, and it
is why the field is on the row rather than in a lookup table.