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

# Location Records

> Signed, verifiable location data with attribution and integrity

<Note>**Research Preview** — APIs may change. [GitHub](https://github.com/AstralProtocol)</Note>

# Location records

A location record is signed, verifiable location data artifact. It takes raw geospatial data and adds what [GeoJSON](/concepts/geojson) alone cannot provide: attribution (who created it) and integrity (proof it hasn't been tampered with).

In the Astral ecosystem, location records conform to v0.2 of the [Location Protocol](https://spec.decentralizedgeo.org) specification. The Location Protocol provides a lightweight data schema that wraps spatial data in any format, to improve interoperability so that spatial data can be parsed and interpreted across distributed systems.

## What signing adds

| Property                 | Raw GeoJSON                       | Signed location record                                                                              |
| ------------------------ | --------------------------------- | --------------------------------------------------------------------------------------------------- |
| **Geometry**             | Yes                               | Yes                                                                                                 |
| **Attribution**          | No — anyone could have created it | Yes — cryptographic signature ties it to a specific identity                                        |
| **Integrity**            | No — could be modified silently   | Yes — any modification invalidates the signature                                                    |
| **Verifiable timestamp** | No                                | Sometimes — if the attestation was anchored or registered on a blockchain or other timestamp server |
| **Correspondence**       | No                                | No — signing proves who *claimed* this location, not that they *were* there                         |

The last row is important. A signed location record proves that a specific identity attested to a specific location at a specific time. It does not prove the attester was physically present. That's what [location proofs](/concepts/location-proofs) add.

<Tip>We use the term "correspondence" to refer to how well a digital spatial data record *corresponds* to physical reality.</Tip>

## EAS attestations

Astral's v0 implementation uses [Ethereum Attestation Service (EAS)](https://attest.org/) for signed location records. EAS provides:

* **Onchain attestations** — stored directly on EAS contracts, referenced by UID (unique identifier), permanent and immutable
* **Offchain attestations** — stored on user devices, centralized servers, IPFS or other infrastructure, referenced by UID + URI, no gas cost, EIP-712 signed

Both carry the same cryptographic guarantees. The difference is storage: onchain attestations live on the blockchain; offchain attestations live wherever you put them but are still cryptographically verifiable.

Other implementations — for example, on ATProto — are in development, and we plan to add support in time.

## Location Protocol v0.2 schema

Location records conform to the [Location Protocol v0.2](https://github.com/DecentralizedGeo/location-protocol-spec/tree/v0.2-draft) schema:

| Field           | Type   | Description                             |
| --------------- | ------ | --------------------------------------- |
| `lp_version`    | string | Protocol version (e.g., "0.2")          |
| `location_type` | string | Type of location data (e.g., "GeoJSON") |
| `location`      | bytes  | Encoded location data                   |
| `srs`           | string | Spatial reference system as OGC URI     |

<Warning>
  We are actively verifying that deployed schemas conform to Location Protocol v0.2. There may be inconsistencies between the documentation, deployed schemas, and the spec. See [GitHub issue #11](https://github.com/AstralProtocol/astral-location-services/issues/11) for status.
</Warning>

## Storage options

<CardGroup cols={2}>
  <Card title="Onchain" icon="link">
    * Stored on EAS contracts
    * Referenced by chain ID + UID
    * Higher gas cost
    * Permanent, immutable
  </Card>

  <Card title="Offchain" icon="cloud">
    * Held on user devices or stored on IPFS, servers, etc.
    * Referenced by UID + URI
    * No gas cost to create
    * EIP-712 signed
  </Card>
</CardGroup>

For offchain attestations, the UID is deterministically derived from the attestation data. Even when fetching from HTTPS (not content-addressed), Astral verifies that the fetched attestation produces the expected UID. Mismatch means rejection.

<Card title="Next: Location proofs" icon="shield-check" href="/concepts/location-proofs">
  Adding evidence of physical correspondence
</Card>

***

**See also:**

* [SDK: Location module](/sdk/location) — creating, fetching, and querying location records
* [API: Types](/api-reference/types) — input format reference