openapi: 3.1.0
info:
  title: Materials Project Defect Tasks Materials Similarity API
  description: "\nThe Materials Project API allows anyone to have direct access to current, up-to-date information from the Materials Project database in a structured way.\n\nThis allows for analysis, development of automated tools, machine learning, downloading personal copies of the Materials Project database and more on a large scale.\n\nThe API is offered with the hopes of making Materials Project data more useful to you. We want you to use our data! As such, the API is offered free-of-charge and we support several tools to help you get started.\n\n## API Key\nTo make any request to the Materials Project API, you must use an API key. Your API key is generated for you automatically upon registering with the Materials Project website and is synced with the email you used to register.\n\nRemember to keep your API key safe and to not share it with anyone you do not trust.\n\nIf you are logged in, you can always access your API key from this page or from your [dashboard](https://next-gen.materialsproject.org/dashboard).\n\nIf you intend heavy API usage, you can give us a heads up by sending a message to <heavy.api.use@materialsproject.org>. With the exception of retrieving charge densities, this is not required, but may help us if we see unusual load on our servers.\n\n## Accessing Data\nTo use the API, you have three options:\n\n1. You can use our first-party supported Python client. This is the recommend route. The `mp-api` package containing the client is pip installable.\n\n    ```\n    pip install mp-api\n    ```\n\n    The `MPRester` client can be accessed by importing from it. This will ultimately replace the legacy `MPRester` available in pymatgen.\n\n    For more details on how to use this, including code examples, please see <https://next-gen.materialsproject.org/api>.\n\n2. You can demo the API interactively on this documentation page. Click the \"Authorize\" button, paste in your API key, and then click the appropriate section to try out a query.\n\n3. Since this is a REST API, and offers a fully-compliant OpenAPI specification, it's possible to use the API with many libraries in many languages and environments, including JavaScript, MATLAB, Mathematica, etc. However, we do not offer first-party support for explaining how to do this, and you will have to follow the specification yourself.\n\n"
  version: 0.86.4rc5.dev1+g77c2c1315
  x-logo:
    url: https://raw.githubusercontent.com/materialsproject/emmet/master/emmet-api/emmet/api/core/assets/mp_logo_small.png
security:
- ApiKeyAuth: []
tags:
- name: Materials Similarity
  description: Route providing a computed similarity metric between materials following the             methodology discussed by Zimmerman *et al.* in [10.3389/fmats.2017.00034](https://doi.org/10.3389/fmats.2017.00034)             and [10.1039/C9RA07755C](https://doi.org/10.1039/C9RA07755C).             Note that similarity data has not been calculated for all materials in the Materials             Project database. See the `SimilarityDoc` schema for a full list of fields returned by this route.
paths:
  /materials/similarity/:
    get:
      tags:
      - Materials Similarity
      summary: Get SimilarityDoc documents
      operationId: search_materials_similarity__get
      parameters:
      - name: material_ids
        in: query
        required: false
        schema:
          anyOf:
          - type: string
          - type: 'null'
          description: Comma-separated list of material_id values to query on
          title: Material Ids
        description: Comma-separated list of material_id values to query on
      - name: _page
        in: query
        required: false
        schema:
          type: integer
          description: Page number to request (takes precedent over _limit and _skip).
          title: ' Page'
        description: Page number to request (takes precedent over _limit and _skip).
      - name: _per_page
        in: query
        required: false
        schema:
          type: integer
          description: Number of entries to show per page (takes precedent over _limit and _skip). Limited to 1000.
          default: 100
          title: ' Per Page'
        description: Number of entries to show per page (takes precedent over _limit and _skip). Limited to 1000.
      - name: _skip
        in: query
        required: false
        schema:
          type: integer
          description: Number of entries to skip in the search.
          default: 0
          title: ' Skip'
        description: Number of entries to skip in the search.
      - name: _limit
        in: query
        required: false
        schema:
          type: integer
          description: Max number of entries to return in a single query. Limited to 1000.
          default: 100
          title: ' Limit'
        description: Max number of entries to return in a single query. Limited to 1000.
      - name: _fields
        in: query
        required: false
        schema:
          type: string
          description: 'Fields to project from SimilarityDoc as a list of comma separated strings.                    Fields include: `builder_meta` `nsites` `elements` `nelements` `composition` `composition_reduced` `formula_pretty` `formula_anonymous` `chemsys` `volume` `density` `density_atomic` `symmetry` `material_id` `deprecated` `deprecation_reasons` `last_updated` `origins` `warnings` `structure` `property_name` `sim` `feature_vector` `method`'
          title: ' Fields'
        description: 'Fields to project from SimilarityDoc as a list of comma separated strings.                    Fields include: `builder_meta` `nsites` `elements` `nelements` `composition` `composition_reduced` `formula_pretty` `formula_anonymous` `chemsys` `volume` `density` `density_atomic` `symmetry` `material_id` `deprecated` `deprecation_reasons` `last_updated` `origins` `warnings` `structure` `property_name` `sim` `feature_vector` `method`'
      - name: _all_fields
        in: query
        required: false
        schema:
          type: boolean
          description: Include all fields.
          default: false
          title: ' All Fields'
        description: Include all fields.
      responses:
        '200':
          description: Search for a SimilarityDoc
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Response_SimilarityDoc_'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
  /materials/similarity/match/:
    get:
      tags:
      - Materials Similarity
      summary: Get SimilarityDoc documents
      operationId: search_materials_similarity_match__get
      parameters:
      - name: feature_vector_hex
        in: query
        required: true
        schema:
          type: string
          maxLength: 3000
          description: A compressed, hex representation of a row unit vector of floats.
          title: Feature Vector Hex
        description: A compressed, hex representation of a row unit vector of floats.
      - name: feature_vector_norm
        in: query
        required: true
        schema:
          type: number
          description: The norm of the feature vector
          title: Feature Vector Norm
        description: The norm of the feature vector
      - name: method
        in: query
        required: false
        schema:
          anyOf:
          - type: string
          - type: 'null'
          description: The method used to embed a structure as a feature vector.
          title: Method
        description: The method used to embed a structure as a feature vector.
      - name: _limit
        in: query
        required: false
        schema:
          type: integer
          description: Max number of entries to return in a single query. Limited to 10 by default
          default: 10
          title: ' Limit'
        description: Max number of entries to return in a single query. Limited to 10 by default
      responses:
        '200':
          description: Get SimilarityDoc data
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Response_SimilarityDoc_'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
components:
  schemas:
    Response_SimilarityDoc_:
      properties:
        data:
          anyOf:
          - items:
              $ref: '#/components/schemas/SimilarityDoc'
            type: array
          - type: 'null'
          title: Data
          description: List of returned data
        errors:
          anyOf:
          - items:
              $ref: '#/components/schemas/Error'
            type: array
          - type: 'null'
          title: Errors
          description: Any errors on processing this query
        meta:
          anyOf:
          - $ref: '#/components/schemas/Meta'
          - type: 'null'
          description: Extra information for the query
      type: object
      title: Response[SimilarityDoc]
    EmmetMeta:
      properties:
        emmet_version:
          anyOf:
          - type: string
          - type: 'null'
          title: Emmet Version
          description: The version of emmet this document was built with.
          default: 0.86.4rc4
        pymatgen_version:
          anyOf:
          - type: string
          - type: 'null'
          title: Pymatgen Version
          description: The version of pymatgen this document was built with.
          default: 2026.4.16
        run_id:
          anyOf:
          - type: string
          - type: 'null'
          title: Run Id
          description: The run id associated with this data build.
        batch_id:
          anyOf:
          - type: string
          - type: 'null'
          title: Batch Id
          description: Identifier corresponding to the origin of this document's blessed task.
        database_version:
          anyOf:
          - type: string
          - type: 'null'
          title: Database Version
          description: The database version for the built data.
        build_date:
          anyOf:
          - type: string
            format: date-time
          - type: 'null'
          title: Build Date
          description: The build date for this document.
        license:
          anyOf:
          - type: string
            enum:
            - BY-C
            - BY-NC
          - type: 'null'
          title: License
          description: License for the data entry.
      type: object
      title: EmmetMeta
      description: Default emmet metadata.
    SimilarityDoc:
      properties:
        builder_meta:
          anyOf:
          - $ref: '#/components/schemas/EmmetMeta'
          - type: 'null'
          description: Builder metadata.
        nsites:
          anyOf:
          - type: integer
          - type: 'null'
          title: Nsites
          description: Total number of sites in the structure.
        elements:
          anyOf:
          - items:
              type: string
            type: array
          - type: 'null'
          title: Elements
          description: List of elements in the material.
        nelements:
          anyOf:
          - type: integer
          - type: 'null'
          title: Nelements
          description: Number of elements.
        composition:
          anyOf:
          - additionalProperties:
              type: number
            type: object
          - type: 'null'
          title: Composition
          description: Full composition for the material.
        composition_reduced:
          anyOf:
          - additionalProperties:
              type: number
            type: object
          - type: 'null'
          title: Reduced Composition
          description: Simplified representation of the composition.
        formula_pretty:
          anyOf:
          - type: string
          - type: 'null'
          title: Pretty Formula
          description: Cleaned representation of the formula.
        formula_anonymous:
          anyOf:
          - type: string
          - type: 'null'
          title: Anonymous Formula
          description: Anonymized representation of the formula.
        chemsys:
          anyOf:
          - type: string
          - type: 'null'
          title: Chemical System
          description: Dash-separated string of elements in the material.
        volume:
          anyOf:
          - type: number
          - type: 'null'
          title: Volume
          description: Total volume for this structure in ų.
        density:
          anyOf:
          - type: number
          - type: 'null'
          title: Density
          description: Density in g/cm³.
        density_atomic:
          anyOf:
          - type: number
          - type: 'null'
          title: Packing Density
          description: The atomic packing density in ų/atom.
        symmetry:
          anyOf:
          - $ref: '#/components/schemas/SymmetryData'
          - type: 'null'
          description: Symmetry data for this material.
        material_id:
          anyOf:
          - type: string
          - type: 'null'
          title: Material Id
          description: 'The Materials Project ID for the material. This comes in the form: mp-******'
        deprecated:
          type: boolean
          title: Deprecated
          description: Whether this property document is deprecated.
          default: true
        deprecation_reasons:
          anyOf:
          - items:
              type: string
            type: array
          - type: 'null'
          title: Deprecation Reasons
          description: List of deprecation tags detailing why this document isn't valid.
        last_updated:
          type: string
          format: date-time
          title: Last Updated
          description: Timestamp for the most recent calculation update for this property.
        origins:
          anyOf:
          - items:
              $ref: '#/components/schemas/PropertyOrigin'
            type: array
          - type: 'null'
          title: Origins
          description: Dictionary for tracking the provenance of properties.
        warnings:
          items:
            type: string
          type: array
          title: Warnings
          description: Any warnings related to this property.
          default: []
        property_name:
          type: string
          title: Property Name
          default: similarity
        sim:
          anyOf:
          - items:
              $ref: '#/components/schemas/SimilarityEntry'
            type: array
          - type: 'null'
          title: Sim
          description: List containing similar structure data for a given material.
        feature_vector:
          anyOf:
          - items:
              type: number
            type: array
          - type: 'null'
          title: Feature Vector
          description: The feature / embedding vector of the structure.
        method:
          anyOf:
          - type: string
          - type: 'null'
          title: Method
          description: The method used to score similarity.
      type: object
      title: SimilarityDoc
      description: Model for a document containing structure similarity data
    ValidationError:
      properties:
        loc:
          items:
            anyOf:
            - type: string
            - type: integer
          type: array
          title: Location
        msg:
          type: string
          title: Message
        type:
          type: string
          title: Error Type
        input:
          title: Input
        ctx:
          type: object
          title: Context
      type: object
      required:
      - loc
      - msg
      - type
      title: ValidationError
    SimilarityEntry:
      properties:
        task_id:
          anyOf:
          - type: string
          - type: 'null'
          title: Task Id
          description: 'The Materials Project ID for the matched material. This comes in the form: mp-******.'
        nelements:
          anyOf:
          - type: integer
          - type: 'null'
          title: Nelements
          description: Number of elements in the matched material.
        dissimilarity:
          anyOf:
          - type: number
          - type: 'null'
          title: Dissimilarity
          description: Dissimilarity measure for the matched material in %.
        formula:
          anyOf:
          - type: string
          - type: 'null'
          title: Formula
          description: Formula of the matched material.
      type: object
      title: SimilarityEntry
      description: Find similar materials to a specified material based on crystal geometry.
    Meta:
      properties:
        api_version:
          type: string
          title: Api Version
          description: A string containing the version of the Materials API implementation, e.g. v0.9.5
          default: 0.86.4rc5.dev1+g77c2c1315
        time_stamp:
          type: string
          format: date-time
          title: Time Stamp
          description: A string containing the date and time at which the query was executed
        total_doc:
          anyOf:
          - type: integer
            minimum: 0.0
          - type: 'null'
          title: Total Doc
          description: The total number of documents available for this query
        facet:
          anyOf:
          - additionalProperties: true
            type: object
          - type: 'null'
          title: Facet
          description: A dictionary containing the facets available for this query
      additionalProperties: true
      type: object
      title: Meta
      description: Meta information for the MAPI Response.
    SymmetryData:
      properties:
        crystal_system:
          anyOf:
          - type: string
          - type: 'null'
          title: Crystal System
          description: The crystal system for this lattice.
        symbol:
          anyOf:
          - type: string
          - type: 'null'
          title: Space Group Symbol
          description: The spacegroup symbol for the lattice.
        hall:
          anyOf:
          - type: string
          - type: 'null'
          title: Hall Symbol
          description: Hall symbol for the lattice
        number:
          anyOf:
          - type: integer
          - type: 'null'
          title: Space Group Number
          description: The spacegroup number for the lattice.
        point_group:
          anyOf:
          - type: string
          - type: 'null'
          title: Point Group Symbol
          description: The point group for the lattice.
        symprec:
          anyOf:
          - type: number
          - type: 'null'
          title: Symmetry Finding Precision
          description: The precision provided to spglib to determine the symmetry of this structure.
        angle_tolerance:
          anyOf:
          - type: number
          - type: 'null'
          title: Angle Tolerance
          description: Angle tolerance provided to spglib to determine the symmetry of this structure.
        version:
          anyOf:
          - type: string
          - type: 'null'
          title: spglib version
      type: object
      title: SymmetryData
      description: Defines a symmetry data set for materials documents
    Error:
      properties:
        code:
          type: integer
          title: Code
          description: The error code
        message:
          type: string
          title: Message
          description: The description of the error
      type: object
      required:
      - code
      - message
      title: Error
      description: Base Error model for General API.
    PropertyOrigin:
      properties:
        name:
          type: string
          title: Name
          description: The property name
        task_id:
          anyOf:
          - type: string
            pattern: ^([A-Za-z]+-)?(\d+)(-[A-Za-z0-9]+)*$
            examples:
            - mp-3534
            - '3453'
            - mp-834-Ag
          - type: string
            examples:
            - mp-ft
            - task:pqrs
          title: Task Id
          description: The calculation ID this property comes from.
        last_updated:
          type: string
          format: date-time
          title: Last Updated
          description: The timestamp when this calculation was last updated
      type: object
      required:
      - name
      - task_id
      title: PropertyOrigin
      description: Provenance document for the origin of properties in a material document
    HTTPValidationError:
      properties:
        detail:
          items:
            $ref: '#/components/schemas/ValidationError'
          type: array
          title: Detail
      type: object
      title: HTTPValidationError
  securitySchemes:
    ApiKeyAuth:
      descriptions: MP API key to authorize requests
      name: X-API-KEY
      in: header
      type: apiKey