> ## Documentation Index > Fetch the complete documentation index at: https://docs.sonarx.com/llms.txt > Use this file to discover all available pages before exploring further. # Filter Fee History > Get transaction fee data for a range of blocks **Range Filter Constraint**: Use either block range (`from_block`/`to_block`) OR datetime range (`from_datetime`/`to_datetime`), but not both simultaneously. These filter pairs are mutually exclusive. ## OpenAPI ````yaml POST /api/v1/customer/{chain}/fee-history/filter openapi: 3.1.0 info: title: SonarX EVM API - Transactions description: >- Query transaction data, receipts, and fee history for EVM-compatible networks. version: 1.0.0 servers: - url: https://api-gateway.sonarx.com description: Production API security: - apiKey: [] tags: - name: Transactions description: Query transaction data, receipts, and fee history paths: /api/v1/customer/{chain}/fee-history/filter: post: tags: - Transactions summary: Filter Fee History description: >- Get transaction fee data for a range of blocks. Use either block range or datetime range, not both. operationId: filterFeeHistory parameters: - $ref: '#/components/parameters/ChainPath' - $ref: '#/components/parameters/Limit' - $ref: '#/components/parameters/Offset' requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/RangeFilterRequest' example: from_block: 81901160 to_block: 81901165 responses: '200': description: Fee history data content: application/json: schema: $ref: '#/components/schemas/FeeHistoryResponse' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '500': $ref: '#/components/responses/InternalError' components: parameters: ChainPath: name: chain in: path description: The blockchain network to query required: true schema: type: string enum: - polygon example: polygon Limit: name: limit in: query description: Maximum number of results (1-50) required: false schema: type: integer minimum: 1 maximum: 50 default: 10 Offset: name: offset in: query description: Number of results to skip for pagination required: false schema: type: integer minimum: 0 default: 0 schemas: RangeFilterRequest: type: object description: >- Base filter request with range parameters. Validation rules: (1) Must provide either block range OR datetime range, not both and not neither. (2) When using block range, both from_block AND to_block are required. (3) When using datetime range, both from_datetime AND to_datetime are required. (4) to_block must be >= from_block. (5) to_datetime must be >= from_datetime. (6) Block range cannot exceed 100 blocks. properties: from_block: type: integer minimum: 0 description: Start block number. Required if using block range. to_block: type: integer minimum: 0 description: >- End block number. Required if using block range. Must be >= from_block and within 100 blocks. from_datetime: type: string format: date-time description: >- Start datetime (ISO 8601, timezone required, e.g., 2024-01-15T10:30:00Z or 2024-01-15T10:30:00+00:00). Required if using datetime range. to_datetime: type: string format: date-time description: >- End datetime (ISO 8601, timezone required, e.g., 2024-01-15T10:30:00Z or 2024-01-15T10:30:00+00:00). Required if using datetime range. Must be >= from_datetime. FeeHistoryResponse: type: object properties: from_block: type: integer nullable: true to_block: type: integer nullable: true from_datetime: type: string nullable: true to_datetime: type: string nullable: true offset: type: integer limit: type: integer result: type: array items: $ref: '#/components/schemas/FeeHistory' count: type: integer example: from_block: 81901160 to_block: 81901165 from_datetime: null to_datetime: null offset: 0 limit: 10 result: - block_number: 81901165 timestamp: 1768922302 datetime: '2026-01-20T15:18:22' base_fee_per_gas: 600795160350 gas_used: 39500751 gas_limit: 65000000 gas_used_ratio: 0.6077038615384616 - block_number: 81901164 timestamp: 1768922300 datetime: '2026-01-20T15:18:20' base_fee_per_gas: 602611448639 gas_used: 34100066 gas_limit: 65000000 gas_used_ratio: 0.5246164 count: 2 FeeHistory: type: object properties: block_number: type: integer timestamp: type: integer datetime: type: string format: date-time base_fee_per_gas: type: integer gas_used: type: integer gas_limit: type: integer gas_used_ratio: type: number example: block_number: 81901165 timestamp: 1768922302 datetime: '2026-01-20T15:18:22' base_fee_per_gas: 600795160350 gas_used: 39500751 gas_limit: 65000000 gas_used_ratio: 0.6077038615384616 ErrorResponse: type: object properties: detail: type: string required: - detail responses: BadRequest: description: Bad Request - Invalid parameters content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: missingBlockNumber: summary: Missing block number value: detail: block_number is required mixedRangeParams: summary: Mixed block and datetime parameters value: detail: >- Cannot mix block and datetime parameters. Use either from_block/to_block or from_datetime/to_datetime, not both missingRangeParams: summary: No range parameters provided value: detail: >- Either block range (from_block/to_block) or datetime range (from_datetime/to_datetime) must be provided incompleteBlockRange: summary: Incomplete block range value: detail: Both from_block and to_block must be provided together blockRangeTooLarge: summary: Block range exceeds limit value: detail: Block range cannot exceed 100 blocks Unauthorized: description: Unauthorized - Invalid or missing API key content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: detail: Invalid API key InternalError: description: Internal Server Error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: detail: An unexpected error occurred securitySchemes: apiKey: type: apiKey in: header name: apikey description: API key for authentication ````