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Map Query

VPS Query API

Query your map to get the device position with respect to Map local origin. The query API takes query image (encoded as base64 string) and other image metadata.

The maximum query image resolution is 1280 pixels in either width or height.

Query a VPS map with specific parameters

post
Authorizations
AuthorizationstringRequired
Bearer authentication header of the form Bearer <token>.
Body
mapCodestringOptional

Code to identify the VPS map (required if mapSetCode is not provided)

Example: MAP-X2P23E7Q35VD
mapSetCodestringOptional

Code to identify the map set (required if mapCode is not provided)

Example: MAPSET-ABC123
queryModestring · enumOptional

Localization engine for this single-frame query. "vps-1" (default) is the fast standard engine (~2s). "vps-2" is a deep-search engine with up to 15% higher recall and improved accuracy, at higher latency (~3-4s). Ideal for offline or challenging scenes. Ignored by the multi-image query endpoint.

Default: vps-1Example: vps-2Possible values:
hintMapCodesstring[]Optional

List of map codes for spatial hints (only valid with mapSetCode)

Example: ["MAP-X2P23E7Q35VD","MAP-Y3Q34F8R46WE"]
hintPositionnumber[]Optional

Position hint [x, y, z] for spatial filtering. Must be in the map's left-handed (LHS / Unity) coordinate system, the same frame as the position field in a successful localization response (isRightHanded=false).

Example: [2.5,0.1,8]
geoHintnumber[]Optional

Geographic hint [latitude, longitude, altitude] - converts to local hintPosition

Example: [37.7749,-122.4194,10]
hintRadiusnumber · min: 5 · max: 100Optional

Search radius in meters for spatial filtering (default 25m). Only applies when geoHint or hintPosition is provided. Range 5-100.

Example: 25
use2DFilteringbooleanOptional

When true, skip altitude (Y-axis) in geoHint spatial filtering, using only horizontal distance (X and Z axes). Only applies when geoHint is provided.

Default: falseExample: false
hintFloorHeightnumber[] · min: 2 · max: 2Optional

Floor height band [y_min, y_max] in map-local coordinates. Search run within this vertical range. Works for both single Map and MapSet (positions are in global/MapSet coordinate space). Order does not matter, so [-3, -1] and [-1, -3] both select y ∈ [-3, -1].

Example: [1.5,4.5]
convertToGeoCoordinatesbooleanOptional

Convert result to geographic coordinates (adds GeoPose to response)

Example: false
isRightHandedbooleanOptional

Flag to indicate if response pose is in right-handed coordinate system

Example: false
queryImagestring · base64Required

Base64 encoded image data

Example: data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAA8AAAALQCAIAAADQFY7jAAAgAElEQVR4AaS9+5NdR5Lfh34BjW4AxJMgOTN8zCw5OzHriV2vvFrZDjtCVki2Xt5VaKVdybLClsL+3xz23+DQr9ZPlmO16xmvh
Responses
200

Query successful

application/json
poseFoundbooleanRequired

Indicates if the pose was successfully found

Example: true
confidencenumberRequired

Confidence score of the pose estimation

Example: 0.46875
mapIdsstring[]Optional

Array of matched map IDs

Example: ["67e12d4bff7ecf561f2f8a0c"]
mapCodesstring[]Optional

Array of matched map codes

Example: ["MAP_RJFKKWQ1787J"]
responseTimenumberOptional

Response time in milliseconds

Example: 2572
post/vps/map/query
POST /v1/vps/map/query HTTP/1.1
Host: api.multiset.ai
Authorization: Bearer YOUR_SECRET_TOKEN
Content-Type: application/json
Accept: */*
Content-Length: 651

{
  "mapCode": "MAP-X2P23E7Q35VD",
  "mapSetCode": "MAPSET-ABC123",
  "queryMode": "vps-2",
  "hintMapCodes": [
    "MAP-X2P23E7Q35VD",
    "MAP-Y3Q34F8R46WE"
  ],
  "hintPosition": [
    2.5,
    0.1,
    8
  ],
  "geoHint": [
    37.7749,
    -122.4194,
    10
  ],
  "hintRadius": 25,
  "use2DFiltering": false,
  "hintFloorHeight": [
    1.5,
    4.5
  ],
  "convertToGeoCoordinates": false,
  "cameraIntrinsics": {
    "fx": 664.3856201171875,
    "fy": 664.3856201171875,
    "px": 478.9782409667969,
    "py": 364.9932861328125
  },
  "isRightHanded": false,
  "resolution": {
    "width": 960,
    "height": 720
  },
  "queryImage": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAA8AAAALQCAIAAADQFY7jAAAgAElEQVR4AaS9+5NdR5Lfh34BjW4AxJMgOTN8zCw5OzHriV2vvFrZDjtCVki2Xt5VaKVdybLClsL+3xz23+DQr9ZPlmO16xmvh"
}
{
  "poseFound": true,
  "position": {
    "x": -5.89516855615433,
    "y": 1.225031596452081,
    "z": 2.2112895596804227
  },
  "rotation": {
    "x": -0.007873432249486393,
    "y": 0.8212519784928444,
    "z": 0.03204363652415735,
    "w": 0.5696107462509017
  },
  "confidence": 0.46875,
  "mapIds": [
    "67e12d4bff7ecf561f2f8a0c"
  ],
  "mapCodes": [
    "MAP_RJFKKWQ1787J"
  ],
  "responseTime": 2572
}

Sample Response (JSON Body)

Query a VPS map or mapset using form-data

post
Authorizations
AuthorizationstringRequired
Bearer authentication header of the form Bearer <token>.
Body
mapCodestringOptional

The map code for the map to query (required if mapSetCode is not provided)

mapSetCodestringOptional

The map set code for the map set to query (required if mapCode is not provided)

queryModestring · enumOptional

Localization engine for this single-frame query. "vps-1" (default) is the fast standard engine (~2s). "vps-2" is a deep-search engine with up to 15% higher recall and improved accuracy, at higher latency (~3-4s). Ideal for offline or challenging scenes. Ignored by the multi-image query endpoint.

Default: vps-1Example: vps-2Possible values:
isRightHandedstring · enumOptionalExample: truePossible values:
fxstringRequiredExample: 669.535888671875
fystringRequiredExample: 669.535888671875
pxstringRequiredExample: 478.8777160644531
pystringRequiredExample: 364.9244079589844
widthstringRequiredExample: 960
heightstringRequiredExample: 720
queryImagestring · binaryRequired

Image file for multipart requests

convertToGeoCoordinatesstring · enumOptional

Convert result to geographic coordinates

Example: falsePossible values:
hintMapCodesstring[]Optional

List of map codes for hints (only valid with mapSetCode)

Example: ["MAP-X2P23E7Q35VD","MAP-Y3Q34F8R46WE"]
hintPositionstringOptional

Position hint "x,y,z" (comma-separated string). Must be in the map's left-handed (LHS / Unity) coordinate system, the same frame as the position field in a successful localization response (isRightHanded=false).

Example: 2.5,0.1,8.0
geoHintstringOptional

Geographic hint "latitude,longitude,altitude" (comma-separated)

Example: 37.7749,-122.4194,10.0
hintRadiusstringOptional

Search radius in meters for spatial filtering (default 25m). Only applies when geoHint or hintPosition is provided. Range 5-100.

Example: 25
use2DFilteringstring · enumOptional

When true, skip altitude (Y-axis) in geoHint spatial filtering. Only applies when geoHint is provided.

Example: falsePossible values:
hintFloorHeightstringOptional

JSON-encoded floor height band "[y_min, y_max]" in map-local coordinates. Search run within this vertical range. Order does not matter.

Example: [1.5, 4.5]
Responses
200

Query successful

application/json
poseFoundbooleanOptional

Indicates if the pose was successfully found

confidencenumberOptional
mapIdsstring[]Optional
mapCodesstring[]Optional
responseTimenumberOptional
post/vps/map/query-form
POST /v1/vps/map/query-form HTTP/1.1
Host: api.multiset.ai
Authorization: Bearer YOUR_SECRET_TOKEN
Content-Type: multipart/form-data
Accept: */*
Content-Length: 457

{
  "mapCode": "text",
  "mapSetCode": "text",
  "queryMode": "vps-2",
  "isRightHanded": "true",
  "fx": "669.535888671875",
  "fy": "669.535888671875",
  "px": "478.8777160644531",
  "py": "364.9244079589844",
  "width": "960",
  "height": "720",
  "queryImage": "binary",
  "convertToGeoCoordinates": "false",
  "hintMapCodes": [
    "MAP-X2P23E7Q35VD",
    "MAP-Y3Q34F8R46WE"
  ],
  "hintPosition": "2.5,0.1,8.0",
  "geoHint": "37.7749,-122.4194,10.0",
  "hintRadius": "25",
  "use2DFiltering": "false",
  "hintFloorHeight": "[1.5, 4.5]"
}
{
  "poseFound": true,
  "position": {
    "x": -2.8765866867008025,
    "y": 1.4018881843419664,
    "z": 7.677072632098843
  },
  "rotation": {
    "x": -0.0033476528966347096,
    "y": 0.6750939967230872,
    "z": -0.00310829178339555,
    "w": 0.7377175796541121
  },
  "confidence": 0.9175769612711023,
  "mapIds": [
    "67e12d4bff7ecf561f2f8a0c"
  ],
  "mapCodes": [
    "MAP_RJFKKWQ1787J"
  ],
  "responseTime": 2669
}

Sample Response (Form Data)

FormData Content-Type: When using fetch or similar HTTP clients with FormData, do not manually set the Content-Type header. The browser automatically sets it to multipart/form-data with the required boundary string. Manually setting it will strip the boundary and cause a parse error.

Code Example (Python)

Spatial Hint: hintPosition

The hintPosition parameter restricts the localization search to a radius around a given point in the map, speeding up the query and improving accuracy in visually repetitive scenes.

Parameter
Type
Description

hintPosition

[x, y, z]

Hint point in the map's left-handed (LHS / Unity) coordinate system

hintRadius

number

Search radius in meters (default 25, range 5–100)

hintPosition is in LHS (Unity) coordinates, the same coordinate system returned in the position field of a successful localization response (isRightHanded: false). A previous localization result's position can be passed directly as the hint. If your application works in right-handed space (e.g. ROS, Three.js), convert to LHS before sending.

On form-data endpoints, pass hintPosition as a JSON-encoded string, e.g. "[2.5, 0.1, 8.0]". See Pose Prior : HintPosition for the full guide.

Floor-Level Search: hintFloorHeight

The hintFloorHeight parameter limits the search to a specific vertical band, enabling floor-level localization in multi-floor buildings.

Parameter
Type
Description

hintFloorHeight

[y_min, y_max]

Vertical band in map-local Y coordinates

Rules:

  • Both values are in map-local coordinates (or global MapSet coordinates for MapSet queries)

  • Order does not matter: [-3, -1] and [-1, -3] both select images with y ∈ [-3, -1]

  • Can be combined with hintPosition: spatial filter runs first, height filter applies on the result

Examples:

Query Mode: queryMode

The queryMode parameter selects which localization engine runs your query, letting you trade latency for accuracy. The request and response format stay exactly the same on both engines.

Value
Engine
Description

vps-1

Standard (default)

The fast standard single-image localization engine, roughly 2 seconds. Best for real-time, interactive localization.

vps-2

Deep Search

A deep-search engine with up to 15% higher recall and improved accuracy, at higher latency (around 3 to 4 seconds). Best for offline or background workflows and challenging, visually repetitive scenes.

Rules:

  • Optional. When omitted, the query runs on vps-1, so existing integrations are unaffected.

  • Supported on both single-image endpoints: /vps/map/query (JSON) and /vps/map/query-form (form-data). It is ignored by the multi-image query endpoint.

  • Can be combined with all localization parameters (hintPosition, hintRadius, hintFloorHeight, geoHint, hintMapCodes).

  • Works with Maps, MapSets, and versioned maps.

Examples:

Use vps-2 when accuracy matters more than latency, for example when placing persistent content or localizing in repetitive corridors. For high-frequency relocalization during an AR session, vps-1 remains the recommended default. You can also try both engines on your own datasets from the Developer Portal simulation viewer. See Query Mode for guidance on choosing between the two.

VPS Multi Image Query API

Multi-image query API requires a minimum of 4 images in each request. Up to 6 images can be passed. Higher image counts increase localization robustness and accuracy but may compromise latency.

About image#_data properties: The image1_data, image2_data, etc. fields contain the local SLAM tracking data (position and rotation) for when each image was captured. This is the device pose in the local coordinate system from ARKit (iOS) or ARCore (Android) at the moment the image was taken.

Multi-image query for a VPS map or map set

post

Performs a query using several uploaded images, along with camera intrinsics and a map or map-set identifier. Requires a minimum of 4 images and accepts a maximum of 6 in a single request.

The request is multipart/form-data. The image binaries are sent as file parts named image1 to image6, and every other field, including each imageN_data tracking pose, is sent as a plain text part. Each image file part must have a matching imageN_data part, or the request fails with 400.

Authorizations
AuthorizationstringRequired
Bearer authentication header of the form Bearer <token>.
Body
isRightHandedstring · enumOptional

Specifies whether the coordinate system is right-handed. Because this is form-data, it's sent as a string ("true" or "false").

Example: truePossible values:
widthstringRequired

The width (in pixels) of the input image(s).

Example: 960
heightstringRequired

The height (in pixels) of the input image(s).

Example: 720
pxstringRequired

The principal point x-coordinate.

Example: 478.838623046875
pystringRequired

The principal point y-coordinate.

Example: 365.346618652343
fxstringRequired

The focal length along x-axis.

Example: 670.4620971679688
fystringRequired

The focal length along y-axis.

Example: 670.4620971679688
mapCodestringOptional

Code to identify the map (required if mapSetCode is not provided).

mapSetCodestringOptional

A code to identify the map set.

convertToGeoCoordinatesstring · enumOptional

Convert result to geographic coordinates

Example: falsePossible values:
hintMapCodesstring[]Optional

List of map codes for hints (only valid with mapSetCode)

Example: ["MAP-X2P23E7Q35VD","MAP-Y3Q34F8R46WE"]
hintPositionstringOptional

Position hint "x,y,z" (comma-separated string). Must be in the map's left-handed (LHS / Unity) coordinate system — the same frame as the position field in a successful localization response (isRightHanded=false).

Example: 2.5,0.1,8.0
geoHintstringOptional

Geographic hint "latitude,longitude,altitude" (comma-separated)

Example: 37.7749,-122.4194,10.0
hintRadiusstringOptional

Search radius in meters for spatial filtering (default 25m). Only applies when geoHint or hintPosition is provided. Range 5-100.

Example: 25
use2DFilteringstring · enumOptional

When true, skip altitude (Y-axis) in geoHint spatial filtering. Only applies when geoHint is provided.

Example: falsePossible values:
hintFloorHeightstringOptional

JSON-encoded floor height band "[y_min, y_max]" in map-local coordinates. Search run within this vertical range. Order does not matter.

Example: [1.5, 4.5]
image1string · binaryRequired

The first image file to be uploaded.

image1_datastringOptional

JSON-encoded metadata for image1 (e.g., position and rotation).

Example: {"x":-5.1772,"y":0.2936,"z":-2.6439,"qx":-0.0185,"qy":0.9949,"qz":-0.0691,"qw":0.0703}
image2string · binaryOptional

The second image file to be uploaded.

image2_datastringOptional

JSON-encoded metadata for image2.

Example: {"x":-3.12,"y":1.01,"z":2.56,"qx":0.0,"qy":0.707,"qz":0.0,"qw":0.707}
image3string · binaryOptional

The third image file to be uploaded.

image3_datastringOptional

JSON-encoded metadata for image3.

Example: {"x":1.23,"y":-0.56,"z":5.0,"qx":-0.0185,"qy":0.9949,"qz":-0.0691,"qw":0.0703}
image4string · binaryOptional

The fourth image file to be uploaded.

image4_datastringOptional

JSON-encoded metadata for image4.

Example: {"x":10.0,"y":-2.0,"z":0.0,"qx":0.0,"qy":1.0,"qz":0.0,"qw":0.0}
Responses
200

Query successful

application/json
poseFoundbooleanOptional
imageIdstringOptional
mapIdsstring[]Optional
confidencenumberOptional
mapCodesstring[]Optional
responseTimenumberOptional
post/vps/map/multi-image-query
POST /v1/vps/map/multi-image-query HTTP/1.1
Host: api.multiset.ai
Authorization: Bearer YOUR_SECRET_TOKEN
Content-Type: multipart/form-data
Accept: */*
Content-Length: 899

{
  "isRightHanded": "true",
  "width": "960",
  "height": "720",
  "px": "478.838623046875",
  "py": "365.346618652343",
  "fx": "670.4620971679688",
  "fy": "670.4620971679688",
  "mapCode": "",
  "mapSetCode": "",
  "convertToGeoCoordinates": "false",
  "hintMapCodes": [
    "MAP-X2P23E7Q35VD",
    "MAP-Y3Q34F8R46WE"
  ],
  "hintPosition": "2.5,0.1,8.0",
  "geoHint": "37.7749,-122.4194,10.0",
  "hintRadius": "25",
  "use2DFiltering": "false",
  "hintFloorHeight": "[1.5, 4.5]",
  "image1": "binary",
  "image1_data": "{\"x\":-5.1772,\"y\":0.2936,\"z\":-2.6439,\"qx\":-0.0185,\"qy\":0.9949,\"qz\":-0.0691,\"qw\":0.0703}",
  "image2": "binary",
  "image2_data": "{\"x\":-3.12,\"y\":1.01,\"z\":2.56,\"qx\":0.0,\"qy\":0.707,\"qz\":0.0,\"qw\":0.707}",
  "image3": "binary",
  "image3_data": "{\"x\":1.23,\"y\":-0.56,\"z\":5.0,\"qx\":-0.0185,\"qy\":0.9949,\"qz\":-0.0691,\"qw\":0.0703}",
  "image4": "binary",
  "image4_data": "{\"x\":10.0,\"y\":-2.0,\"z\":0.0,\"qx\":0.0,\"qy\":1.0,\"qz\":0.0,\"qw\":0.0}"
}
{
  "poseFound": true,
  "estimatedPose": {
    "position": {
      "x": 3.9023228363353613,
      "y": 2.2199969114542415,
      "z": 7.684019738005462
    },
    "rotation": {
      "x": 0.0008889080606250241,
      "y": 0.7454695784085924,
      "z": -0.022682644709609446,
      "w": 0.6661529967948453
    }
  },
  "trackingPose": {
    "position": {
      "x": 0.0022450201213359833,
      "y": 2.471872329711914,
      "z": -10.018059730529785
    },
    "rotation": {
      "x": 0.030655404552817345,
      "y": 0.14812710881233215,
      "z": -0.00305502163246274,
      "w": -0.9884883761405945
    }
  },
  "imageId": "image4",
  "mapIds": [
    "67e12d4bff7ecf561f2f8a0c"
  ],
  "confidence": 0.34274043817304123,
  "frames": [
    {
      "imageId": "image1",
      "poseFound": true,
      "position": {
        "x": 3.840479122718551,
        "y": 2.235871409437739,
        "z": 7.531184729001473
      },
      "rotation": {
        "x": 0.0104227310558921,
        "y": 0.7218904471209736,
        "z": -0.0248105549134402,
        "w": 0.6914338805274115
      },
      "confidence": 0.2988120487183476
    },
    {
      "imageId": "image2",
      "poseFound": true,
      "position": {
        "x": 3.8697402118840367,
        "y": 2.228145503710395,
        "z": 7.601552884101918
      },
      "rotation": {
        "x": 0.0061140925713855,
        "y": 0.7331886201553348,
        "z": -0.0235510983247741,
        "w": 0.6795726114402537
      },
      "confidence": 0.31204558839107516
    },
    {
      "imageId": "image3",
      "poseFound": false
    },
    {
      "imageId": "image4",
      "poseFound": true,
      "position": {
        "x": 3.9023228363353613,
        "y": 2.2199969114542415,
        "z": 7.684019738005462
      },
      "rotation": {
        "x": 0.0008889080606250241,
        "y": 0.7454695784085924,
        "z": -0.022682644709609446,
        "w": 0.6661529967948453
      },
      "confidence": 0.34274043817304123
    }
  ],
  "mapCodes": [
    "MAP_RJFKKWQ1787J"
  ],
  "responseTime": 4919
}

Sample Response (Multi Image)

Per-image poses (frames)

Alongside the single estimatedPose, the response carries a frames array with one entry per image you sent, in the order the images were numbered. Each entry reports whether that individual image localized on its own, and if it did, the 6-DoF pose computed from it.

Field
Type
Description

imageId

string

Which image this entry describes (image1 to image6), matching the file part you uploaded.

poseFound

boolean

Whether this individual image produced a pose.

position

object

x, y, z in map-local coordinates. Present only when poseFound is true.

rotation

object

Quaternion x, y, z, w. Present only when poseFound is true.

confidence

number

Confidence score for this image alone. May be absent on a frame that did not localize.

How frames relates to the top-level pose:

  • estimatedPose remains the answer to use. It is the consensus pose across all images and is more robust than any single frame.

  • The top-level imageId names the winning frame, so the entry with that imageId carries the same position, rotation, and confidence as estimatedPose.

  • Every pose in frames is in the same coordinate frame as estimatedPose: it follows the isRightHanded value you sent, and on a versioned map it is expressed in the base map's frame.

  • Individual frames can fail while the overall query succeeds. A frame with "poseFound": false has no position or rotation, which is normal when one image in the set is blurred, occluded, or pointed at a featureless surface.

  • frames is informational. It is useful for diagnosing capture quality, spotting outlier viewpoints, and understanding which frames drove the result, but you do not need it for standard localization.

FormData Content-Type: When using fetch or similar HTTP clients with FormData, do not manually set the Content-Type header. The browser automatically sets it to multipart/form-data with the required boundary string. Manually setting it will strip the boundary and cause a parse error.

Code Example (Python)

Split the request in two parts: the image binaries go in files, and every other field, including each imageN_data tracking pose, goes in data as a string.

Rules for the multipart body:

  • File parts must be named image1 to image6, and each one needs a matching imageN_data text part with the same number. A missing imageN_data returns 400 with Missing metadata for imageN.

  • Each imageN_data value is a JSON-encoded string containing x, y, z, qx, qy, qz and qw. All seven keys are required.

  • Send between 4 and 6 images. Fewer returns At least 4 image file is required!, more returns Maximum 6 image files allowed!.

  • Pass exactly one of mapCode or mapSetCode.

  • Do not set the Content-Type header yourself. requests adds multipart/form-data with the boundary when you pass files.

PreviousAuthentication
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