> ## Documentation Index > Fetch the complete documentation index at: https://docs.beaconcha.in/llms.txt > Use this file to discover all available pages before exploring further. # Attestation efficiency > Retrieve normalized attestation inclusion effectiveness for one or more validators. Provide a comma-separated list of validator indices or 0x-prefixed BLS pubkeys (up to the server-enforced limit; default 100). The score is computed for the most recently completed epoch and defined as: `score = 1 + (1 − percentage/100) = 2 − percentage/100`. A score of 1.0 indicates perfect effectiveness (100% inclusion); scores approach 2.0 as effectiveness worsens (0% inclusion). ## OpenAPI ````yaml /api/v1/bundled.yaml get /api/v1/validator/{indexOrPubkey}/attestationefficiency openapi: 3.0.4 info: title: beaconcha.in API Documentation license: name: GPL-3.0 url: https://www.gnu.org/licenses/gpl-3.0.en.html description: >- > ⚠️ No new features or endpoints will be added to V1. We recommend the [V2 API](/api/overview) for all new projects. See the [migration guide](/api/v1-to-v2-migration). ## Introduction **Advanced and reliable API for accessing comprehensive Ethereum blockchain data.** - **Free Usage Policy:** The API is free to use under a fair use policy, with rate limits of 10 requests per minute per IP. - **Caching:** All responses are cached for 1 minute. - **Higher Usage Plans:** For higher usage plans, visit: [https://beaconcha.in/pricing](https://beaconcha.in/pricing). An API key is required to use these plans. ### API Key Usage API keys can be obtained at [/user/settings](https://beaconcha.in/user/settings) and must be included in requests either as a query string parameter or in the request header. #### Example: Query String Parameter ```bash curl https://beaconcha.in/api/v1/slot/1?apikey= ``` #### Example: Request Header ```bash curl -H 'apikey: ' https://beaconcha.in/api/v1/slot/1 ``` contact: {} version: '1.1' servers: - url: https://beaconcha.in description: Ethereum mainnet - url: https://hoodi.beaconcha.in description: Hoodi Ethereum testnet security: - ApiKeyAuthQuery: [] - ApiKeyAuthHeader: [] tags: - name: Epoch description: Data related to consensus layer epochs - name: Slots description: Data related to consensus layer slots - name: Validators description: Data related to consensus layer validators - name: Rewards description: Data related to validator rewards - name: Sync Committees description: Data related to sync committees - name: Rocketpool description: Data related to the rocketpool protocol - name: ETH.Store® description: Data related to the ETH.Store® metric - name: Validator deposits description: Data related to execution layer validator deposits - name: Blocks description: Data related to execution layer blocks - name: Gas description: Data related to gas prices - name: Address description: Data related to ethereum addresses - name: Network description: Network data - name: Misc description: Miscellaneous data - name: User description: User data - name: Machine Metrics description: Submit machine, beacon-node, and validator-client monitoring metrics paths: /api/v1/validator/{indexOrPubkey}/attestationefficiency: get: tags: - Validators summary: Attestation efficiency description: >- Retrieve normalized attestation inclusion effectiveness for one or more validators. Provide a comma-separated list of validator indices or 0x-prefixed BLS pubkeys (up to the server-enforced limit; default 100). The score is computed for the most recently completed epoch and defined as: `score = 1 + (1 − percentage/100) = 2 − percentage/100`. A score of 1.0 indicates perfect effectiveness (100% inclusion); scores approach 2.0 as effectiveness worsens (0% inclusion). operationId: getValidatorAttestationEfficiency parameters: - name: indexOrPubkey in: path description: >- Comma-separated validator indices and/or public keys (maximum 100 items by default). required: true style: simple explode: false schema: $ref: '#/components/schemas/primitives.indicesOrPubkeys' responses: '200': description: >- Matching validators were retrieved successfully. The `data` array contains one entry per validator with the normalized attestation effectiveness score. content: application/json: schema: allOf: - $ref: '#/components/schemas/types.ApiResponse' - type: object properties: data: type: array items: $ref: >- #/components/schemas/types.ApiValidatorAttestationEfficiencyResponse '400': description: >- The request is invalid (for example, malformed identifier, too many identifiers, or unresolved pubkeys). content: application/json: schema: $ref: '#/components/schemas/types.ApiErrorResponse' examples: invalidParam: summary: Invalid validator identifier value: status: 'ERROR: invalid validator-parameter' data: null tooMany: summary: Too many identifiers value: status: 'ERROR: only a maximum of 100 query parameters are allowed' data: null unresolvedPubkeys: summary: Pubkey did not resolve to an index value: status: >- ERROR: invalid validator argument, pubkey(s) did not resolve to a validator index data: null '500': description: An unexpected server error occurred while processing your request. content: application/json: schema: $ref: '#/components/schemas/types.ApiErrorResponse' examples: serverError: summary: Internal error value: status: 'ERROR: internal server error' data: null components: schemas: primitives.indicesOrPubkeys: type: string description: > Comma-separated list (no spaces) of validator identifiers. Each identifier must be either: - A validator index as a base-10 integer (for example, 652648) - A BLS public key as a 96-hex-character string with or without the 0x prefix (case-insensitive) Resolution and limits: - The server resolves public keys to validator indices before querying data. - The total number of identifiers must not exceed the server-enforced limit (default 100). - Identifiers that cannot be parsed or resolved result in HTTP 400. example: 1,2,3 types.ApiResponse: type: object description: Standard success envelope used by all API endpoints. properties: status: type: string description: >- HTTP-independent status of the API operation. For successful responses this is always "OK". enum: - OK data: description: Response payload specific to the endpoint. nullable: true x-omitempty: true types.ApiValidatorAttestationEfficiencyResponse: type: object description: >- Attestation inclusion effectiveness for a validator expressed as a normalized score. The score is computed from the underlying inclusion percentage as: score = 1 + (1 − percentage/100) = 2 − percentage/100. A score of 1.0 indicates perfect effectiveness (100% inclusion in the most recently completed epoch); a score approaching 2.0 indicates poor effectiveness (0% inclusion). properties: validatorindex: type: integer description: Validator index (>= 0). minimum: 0 example: 21 attestation_efficiency: type: number description: >- Normalized attestation effectiveness score (1.0 = best, 2.0 = worst). See top-level description for the formula. Computed for the most recently completed epoch. minimum: 1 maximum: 2 example: 1.0175 types.ApiErrorResponse: type: object description: Standard error envelope returned when a request fails. properties: status: type: string description: >- Human-readable error indicator and message. The value begins with "ERROR:" followed by details. example: 'ERROR: ' data: type: string description: Optional additional context for the error. Null in most cases. nullable: true default: null securitySchemes: ApiKeyAuthQuery: type: apiKey in: query name: apikey description: '' ApiKeyAuthHeader: type: apiKey in: header name: apikey description: '' ````