Research Preview — This API is under development.

Verify proof

Verify a location proof (a claim bundled with one or more stamps). This endpoint verifies each stamp individually, then cross-correlates them to produce a CredibilityVector — a multidimensional assessment of how well the evidence supports the claim.

POST /verify/v0/proof

The Verify API does not return a single summary score. The CredibilityVector provides spatial, temporal, validity, and independence dimensions so your application can define its own trust model.

Request body

LocationProof

required

The proof to verify. Contains a claim (LocationClaim) and an array of stamps (LocationStamp).

number

Chain ID for EAS attestation signing (e.g., 84532 for Base Sepolia).

boolean

Whether to submit the attestation onchain. Defaults to false.

Example request

curl -X POST https://staging-api.astral.global/verify/v0/proof \
  -H "Content-Type: application/json" \
  -H "X-API-Key: your-api-key" \
  -d '{
    "proof": {
      "claim": {
        "lpVersion": "0.2",
        "locationType": "geojson-point",
        "location": { "type": "Point", "coordinates": [-122.4194, 37.7749] },
        "srs": "http://www.opengis.net/def/crs/OGC/1.3/CRS84",
        "subject": { "scheme": "eth-address", "value": "0x1234..." },
        "radius": 100,
        "time": { "start": 1706900000, "end": 1706903600 }
      },
      "stamps": [
        {
          "lpVersion": "0.2",
          "locationType": "geojson-point",
          "location": { "type": "Point", "coordinates": [-122.4195, 37.7750] },
          "srs": "http://www.opengis.net/def/crs/OGC/1.3/CRS84",
          "temporalFootprint": { "start": 1706901000, "end": 1706901060 },
          "plugin": "proofmode",
          "pluginVersion": "0.1.0",
          "signals": {},
          "signatures": [{ "signer": { "scheme": "device-pubkey", "value": "0x..." }, "algorithm": "secp256k1", "value": "0x...", "timestamp": 1706901030 }]
        },
        {
          "lpVersion": "0.2",
          "locationType": "geojson-point",
          "location": { "type": "Point", "coordinates": [-122.4193, 37.7748] },
          "srs": "http://www.opengis.net/def/crs/OGC/1.3/CRS84",
          "temporalFootprint": { "start": 1706901000, "end": 1706901120 },
          "plugin": "witnesschain",
          "pluginVersion": "0.1.0",
          "signals": {},
          "signatures": [{ "signer": { "scheme": "eth-address", "value": "0x..." }, "algorithm": "secp256k1", "value": "0x...", "timestamp": 1706901060 }]
        }
      ]
    },
    "options": {
      "chainId": 84532
    }
  }'

const response = await fetch('https://staging-api.astral.global/verify/v0/proof', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'X-API-Key': 'your-api-key'
  },
  body: JSON.stringify({
    proof: {
      claim: {
        lpVersion: '0.2',
        locationType: 'geojson-point',
        location: { type: 'Point', coordinates: [-122.4194, 37.7749] },
        srs: 'http://www.opengis.net/def/crs/OGC/1.3/CRS84',
        subject: { scheme: 'eth-address', value: '0x1234...' },
        radius: 100,
        time: { start: 1706900000, end: 1706903600 }
      },
      stamps: [
        // ... stamps array
      ]
    },
    options: { chainId: 84532 }
  })
});

Response

The response contains the verified proof, a credibility vector, and optional EAS attestation data.

LocationProof

required

The verified proof object.

CredibilityVector

required

Multidimensional assessment of how well the stamps support the claim. See CredibilityVector for the full type.

string

required

The evaluation method used (e.g., "multifactor-v0").

number

required

Unix timestamp (seconds) of when the evaluation was performed.

AttestationData

EAS attestation data. Present when chainId is provided. See AttestationData.

DelegatedAttestationData

Delegated attestation for onchain submission. See DelegatedAttestationData.

Example response

Illustrative example. ProofMode verification is working today; the witnesschain stamp below is shown to illustrate multi-source cross-correlation, but WitnessChain (along with gpsd, geoclue, wifi-mls, ip-geolocation) is still experimental. Some details fields shown here (for example certificateChainValid) correspond to checks that are planned but not yet performed in v0 — see the ProofMode plugin for exactly what verification does today. The credibility-vector structure is also still evolving.

{
  "proof": {
    "claim": { "..." : "..." },
    "stamps": ["..."]
  },
  "credibility": {
    "dimensions": {
      "spatial": {
        "meanDistanceMeters": 12.5,
        "maxDistanceMeters": 18.3,
        "withinRadiusFraction": 1.0
      },
      "temporal": {
        "meanOverlap": 0.95,
        "minOverlap": 0.90,
        "fullyOverlappingFraction": 0.5
      },
      "validity": {
        "signaturesValidFraction": 1.0,
        "structureValidFraction": 1.0,
        "signalsConsistentFraction": 1.0
      },
      "independence": {
        "uniquePluginRatio": 1.0,
        "spatialAgreement": 0.88,
        "pluginNames": ["proofmode", "witnesschain"]
      }
    },
    "stampResults": [
      {
        "stampIndex": 0,
        "plugin": "proofmode",
        "signaturesValid": true,
        "structureValid": true,
        "signalsConsistent": true,
        "distanceMeters": 12.5,
        "temporalOverlap": 0.95,
        "withinRadius": true,
        "details": {
          "hashVerified": true,
          "certificateChainValid": true
        }
      },
      {
        "stampIndex": 1,
        "plugin": "witnesschain",
        "signaturesValid": true,
        "structureValid": true,
        "signalsConsistent": true,
        "distanceMeters": 18.3,
        "temporalOverlap": 0.90,
        "withinRadius": true,
        "details": {
          "latencyVerified": true,
          "nodeCount": 3
        }
      }
    ],
    "meta": {
      "stampCount": 2,
      "evaluatedAt": 1706961600,
      "evaluationMode": "local"
    }
  },
  "evaluationMethod": "multifactor-v0",
  "evaluatedAt": 1706961600,
  "attestation": {
    "uid": "0xdef456...",
    "schema": "0x...",
    "attester": "0x590fdb53ed3f0B52694876d42367192a5336700F",
    "recipient": "0x1234...",
    "data": "0x...",
    "revocable": true,
    "refUID": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "signature": "0x..."
  },
  "delegatedAttestation": {
    "signature": "0x...",
    "attester": "0x590fdb53ed3f0B52694876d42367192a5336700F",
    "deadline": 1706403600,
    "nonce": 0
  }
}

Credibility vector

The credibility field is a CredibilityVector with four dimension groups:

`dimensions.spatial`

How close each stamp’s observed location is to the claimed location.

Field	Type	Description
`meanDistanceMeters`	`number`	Average distance between stamp locations and claimed location
`maxDistanceMeters`	`number`	Largest distance from any stamp to the claim
`withinRadiusFraction`	`number`	Fraction of stamps within the claim’s radius (0-1)

`dimensions.temporal`

How well each stamp’s temporal footprint overlaps with the claimed time window.

Field	Type	Description
`meanOverlap`	`number`	Average temporal overlap ratio (0-1)
`minOverlap`	`number`	Smallest overlap of any stamp
`fullyOverlappingFraction`	`number`	Fraction of stamps fully within the claim’s time window

`dimensions.validity`

Fraction of stamps passing each verification check.

Field	Type	Description
`signaturesValidFraction`	`number`	Fraction with valid signatures (0-1)
`structureValidFraction`	`number`	Fraction with valid structure (0-1)
`signalsConsistentFraction`	`number`	Fraction with consistent signals (0-1)

`dimensions.independence`

How independent and corroborative the evidence sources are.

Field	Type	Description
`uniquePluginRatio`	`number`	Ratio of unique plugins to total stamps (0-1)
`spatialAgreement`	`number`	How well stamps agree spatially (0-1)
`pluginNames`	`string[]`	List of plugins that contributed stamps

`stampResults`

Per-stamp verification results. See StampResult for the full type.

`meta`

Field	Type	Description
`stampCount`	`number`	Number of stamps evaluated
`evaluatedAt`	`number`	Unix timestamp (seconds)
`evaluationMode`	`string`	Evaluation mode: `"local"`, `"tee"`, or `"zk"`

Errors

Errors follow RFC 7807:

Type	Status	Description
`invalid-input`	400	Malformed proof, missing claim fields
`validation`	400	Claim validation failed (e.g., missing radius)
`not-implemented`	501	Plugin not supported
`internal`	500	Internal verification error
`rate-limited`	429	Too many requests
`unauthorized`	401	Invalid or missing API key

SDK: Location proofs

See the SDK documentation for client-side usage

​Verify proof

​Request body

​Example request

​Response

​Example response

​Credibility vector

​dimensions.spatial

​dimensions.temporal

​dimensions.validity

​dimensions.independence

​stampResults

​meta

​Errors

SDK: Location proofs

Verify proof

Request body

Example request

Response

Example response

Credibility vector

`dimensions.spatial`

`dimensions.temporal`

`dimensions.validity`

`dimensions.independence`

`stampResults`

`meta`

Errors