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This file documents efforts toward establishing a public API for iD.

URL parameters

iD Standalone

iD supports several URL parameters. When constructing a URL to a standalone instance of iD (e.g., the following parameters are available in the hash portion of the URL:

  • map - A slash separated zoom/latitude/longitude.
    Example: map=20.00/38.90085/-77.02271
  • id - The character 'n', 'w', or 'r', followed by the OSM ID of a node, way or relation, respectively. Selects the specified entity, and, unless a map parameter is also provided, centers the map on it.
  • background - The value from a sourcetag property in iD's imagery list, or a custom tile URL. A custom URL is specified in the format custom:<url>, where the URL can contain the standard tile URL placeholders {x}, {y} and {z}/{zoom}, {ty} for flipped TMS-style Y coordinates, and {switch:a,b,c} for DNS multiplexing.
    Example: background=custom:https://{switch:a,b,c}{zoom}/{x}/{y}.png
  • disable_features - Disables features in the list.
    Example: disable_features=water,service_roads,points,paths,boundaries
    Available features: points traffic_roads service_roads paths buildings landuse boundaries water rail power past_future others
  • gpx - A custom URL for loading a gpx track. Specifying a gpx parameter will automatically enable the gpx layer for display.
    Example: gpx=
  • offset - imagery offset in meters, formatted as east,north.
    Example: offset=-10,5
  • comment - Prefills the changeset comment. Pass a url encoded string.
    Example: comment=CAR%20crisis%2C%20refugee%20areas%20in%20Cameroon
  • hashtags - Prefills the changeset hashtags. Pass a url encoded list of event hashtags separated by commas, semicolons, or spaces. Leading '#' symbols are optional and will be added automatically. (Note that hashtag-like strings are automatically detected in the comment).
    Example: hashtags=%23hotosm-task-592,%23MissingMaps
  • rtl=true - Force iD into right-to-left mode (useful for testing).
  • walkthrough=true - Start the walkthrough automatically
iD on (Rails Port)

When constructing a URL to an instance of iD embedded in the OpenStreetMap Rails Port (e.g., the following parameters are available as regular URL query parameters:

  • map - same as standalone
  • lat, lon, zoom - Self-explanatory.
  • node, way, relation - Select the specified entity.
  • background - same as standalone
  • disable_features - same as standalone
  • gpx - same as standalone
  • offset - same as standalone
  • comment - same as standalone
  • hashtags - same as standalone
  • walkthrough - same as standalone

CSS selectors

iD has a documented and stable set of classes that can be used to apply style or attach behavior to the visual representation of map data via CSS selectors. These classes relate to the vocabulary of the OSM data model, a related geometric vocabulary established by iD, and to the tags present on OSM entities.

OSM Data Model classes

An SVG element on the map to which an iD.Entity has been bound as a datum shall have a class with that datum's type, i.e. either .node or .way. (If and when we add visual representations for relations, .relation may also be valid.)

The visual representation of a single entity may be composed of several elements, e.g. ways are composed of casing and stroke. Such elements will have a distinct class identifying the particular aspect of representation, e.g. .casing and .stroke.

The particular type of SVG element (path, circle, image etc.) that is used to implement that visual representation is explicitly NOT part of the public API. Avoid naming specific tags in CSS selectors; as iD evolves, we may need to change what SVG elements we use in order to implement a particular visual style.

Geometric classes

In addition to the OSM element vocabulary of nodes, ways, and relations, iD has established a related geometric vocabulary consisting of points, vertices, midpoints, lines, and areas.

A point is a node that is not a member of any way. Elements representing points have a .point class. Since a point is always a node, they also have a .node class.

A vertex is a node that is a member of one or more ways. Elements representing points have .vertex and .node classes.

A midpoint is a virtual point drawn midway between two vertices along a way. Midpoints indicate the direction that the way, but can also be selected and dragged to create a new point along the way. Midpoints are classed with a .midpoint class.

A line is a way that is not an area. Elements representing lines have a .line class. Since a line is also a way, they also have a .way class.

An area is a way that is circular, has certain tags, or lacks certain other tags (see iD.Way#isArea for the exact definition). Elements representing areas have .area and .way classes.

Tag classes

Elements also receive classes according to certain of the OSM key-value tags that are assigned to them.

Tag classes are prefixed with tag- (see iD.svgTagClasses for details).


An element may be classed with at most one primary tag class based on its main OSM key -- "building", "highway", "railway", "waterway", etc. (e.g. .tag-highway .tag-highway-residential).


An element may be classed with one or more secondary tag classes based on other interesting OSM keys -- "bridge", "tunnel", "barrier", "surface", etc. (e.g. .tag-bridge .tag-bridge-yes).


An element may be classed with at most one status tag. Status tagging in OSM can be either key or value based, but iD attempts to detect most common lifecycle tagging schemes -- "construction", "proposed", "abandoned", "disused", etc. (e.g. .tag-status .tag-status-construction).

Unpaved Surfaces (highways only)

Most vehicular highways in OSM are assumed to have a smooth paved surface. A highway element may receive the special tag class .tag-unpaved if it contains certain OSM tags indicating a bumpy surface.

Special classes

  • A node that is a member of two or more ways shall have the .shared class.

  • A node that is an endpoint of a linear way shall have the .endpoint class.

  • Two or more nodes at identical coordinates shall each have an .overlapped class. (TODO)

  • Elements comprising the entity currently under the cursor shall have the .hover class. (The :hover psuedo-class is insufficient when an entity's visual representation consists of several elements, only one of which can be :hovered.)

  • Elements that are currently active (being clicked or dragged) shall have the .active class.

  • Elements that are currently selected shall have the .selected class.

Customized Deployments

iD may be used to edit maps in a non-OpenStreetMap environment. This requires certain parts of the iD code to be replaced at runtime by custom code or data.

iD is written in a modular style and bundled with rollup.js, which makes hot code replacement tricky. (ES6 module exports are immutable live bindings). Because of this, the parts of iD which are designed for customization are exported as live bound objects that can be overriden at runtime before initializing the iD context.


The object includes code that talks to other web services.

To replace the OSM service with a custom service that exactly mimics the default OSM service: = serviceMyOSM;

Some services may be removed entirely. For example, to remove the Mapillary service: = undefined;
// or

Background Imagery

iD's background imagery database is stored in the array and can be overridden or modified prior to creating the iD context.

Note that the "None" and "Custom" options will always be shown in the list.

To remove all imagery from iD: = [];

To replace all imagery with a single source: = [{
    "id": "ExampleImagery",
    "name": "My Imagery",
    "type": "tms",
    "template": "http://{switch:a,b,c}{z}/{x}/{y}.png"

Each imagery source should have the following properties:

  • id - Unique identifier for this source (also used as a url paramater)
  • name - Display name for the source
  • type - Source type, currently only tms is supported
  • template - Url template, valid replacement tokens include:
    • {z}, {x}, {y} - for Z/X/Y scheme
    • {-y} or {ty} - for flipped Y
    • {u} - for quadtile scheme
    • {switch:a,b,c} - for parts of the url that can be cycled for connection parallelization

Optional properties:

  • description - A longer source description which, if included, will be displayed in a popup when viewing the background imagery list
  • overlay - If true, this is an overlay layer (a transparent layer rendered above base imagery layer). Defaults to false
  • scaleExtent - Allowable min and max zoom levels, defaults to [0, 20]
  • polygon - Array of coordinate rings within which imagery is valid. If omitted, imagery is assumed to be valid worldwide
  • overzoom - Can this imagery be scaled up when zooming in beyond the max zoom? Defaults to true
  • terms_url - Url to link to when displaying the imagery terms
  • terms_html - Html content to display in the imagery terms
  • terms_text - Text content to display in the imagery terms
  • best - If set to true, this imagery is considered "better than Bing" and may be chosen by default when iD starts. Will display with a star in the background imagery list. Defaults to false

For more details about the structure, see update_imagery.js.


iD's preset database is stored in the object and can be overridden or modified prior to creating the iD context.

The format of the presets object is documented here.

To add a new preset to iD's existing preset database.["aerialway/zipline"] = {
    geometry: ["line"],
    fields: ["incline"],
    tags: { "aerialway": "zip_line" },
    name: "Zipline"

To completely replace iD's default presets with your own: = myPresets;

To run iD with the minimal set of presets that only match basic geometry types: = {
    presets: {
        "area": {
            "name": "Area",
            "tags": {},
            "geometry": ["area"]
        "line": {
            "name": "Line",
            "tags": {},
            "geometry": ["line"]
        "point": {
            "name": "Point",
            "tags": {},
            "geometry": ["point"]
        "vertex": {
            "name": "Vertex",
            "tags": {},
            "geometry": ["vertex"]
        "relation": {
            "name": "Relation",
            "tags": {},
            "geometry": ["relation"]

Minimum Editable Zoom

The minimum zoom at which iD enters the edit mode is configured using the context.minEditableZoom() accessor. The default value is 16. To change this initialise the iD context as:

var id = iD.Context()

This should be set with caution for performance reasons. The OpenStreetMap API has a limitation of 50000 nodes per request.