> ## Documentation Index > Fetch the complete documentation index at: https://docs.endstate.io/llms.txt > Use this file to discover all available pages before exploring further. # Generate an e-value for a test chip > Returns a fresh `e` value for a test chip. POST the returned `e` to `/v1/taps` to test your integration end-to-end. Only valid for test chips, and only with a secret key. ## OpenAPI ````yaml /openapi.json post /v1/test-helpers/taps openapi: 3.1.0 info: title: Endstate API version: 0.1.0 description: Endstate developer API for chip verification and ownership workflows. servers: - url: https://api2.endstate.io description: Production - url: https://api-staging.endstate.io description: Staging security: [] paths: /v1/test-helpers/taps: post: tags: - Test helpers summary: Generate an e-value for a test chip description: >- Returns a fresh `e` value for a test chip. POST the returned `e` to `/v1/taps` to test your integration end-to-end. Only valid for test chips, and only with a secret key. operationId: createTestTap requestBody: content: application/json: schema: $ref: '#/components/schemas/CreateTestTapRequest' example: chip_id: ABCDEF0123 count: 5 responses: '200': description: Generated e-value and count. content: application/json: schema: $ref: '#/components/schemas/CreateTestTapResponse' example: chip_id: ABCDEF0123 e: C78566198547116F3A715DC1C62AF96F count: 5 '400': description: >- The request was malformed or failed validation. | Error code | When | | --- | --- | | `chip.not_a_test_chip` | A tap simulation was attempted on a real chip. Simulation is only available for test chips. | | `validation.failed` | The request failed schema validation. See `error.details` for per-field issues. | x-error-codes: - chip.not_a_test_chip - validation.failed content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: chip.not_a_test_chip: summary: >- A tap simulation was attempted on a real chip. Simulation is only available for test chips. value: error: code: chip.not_a_test_chip message: >- A tap simulation was attempted on a real chip. Simulation is only available for test chips. request_id: req_8e1a7f50-90ab-4cde-f012-3456789abcde doc_url: https://docs.endstate.io/errors/chip-not-a-test-chip validation.failed: summary: >- The request failed schema validation. See `error.details` for per-field issues. value: error: code: validation.failed message: >- The request failed schema validation. See `error.details` for per-field issues. request_id: req_8e1a7f50-90ab-4cde-f012-3456789abcde doc_url: https://docs.endstate.io/errors/validation-failed '401': description: |- Authentication failed. | Error code | When | | --- | --- | | `auth.unauthorized` | Credential is missing or malformed. | x-error-codes: - auth.unauthorized content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: auth.unauthorized: summary: Credential is missing or malformed. value: error: code: auth.unauthorized message: Credential is missing or malformed. request_id: req_8e1a7f50-90ab-4cde-f012-3456789abcde doc_url: https://docs.endstate.io/errors/auth-unauthorized '403': description: >- Authenticated, but not permitted. | Error code | When | | --- | --- | | `auth.forbidden` | Credential is valid but does not have access to the requested resource or action. | x-error-codes: - auth.forbidden content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: auth.forbidden: summary: >- Credential is valid but does not have access to the requested resource or action. value: error: code: auth.forbidden message: >- Credential is valid but does not have access to the requested resource or action. request_id: req_8e1a7f50-90ab-4cde-f012-3456789abcde doc_url: https://docs.endstate.io/errors/auth-forbidden '404': description: >- The resource does not exist within your organization. | Error code | When | | --- | --- | | `chip.not_found` | The chip ID does not exist in your organization. | x-error-codes: - chip.not_found content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: chip.not_found: summary: The chip ID does not exist in your organization. value: error: code: chip.not_found message: The chip ID does not exist in your organization. request_id: req_8e1a7f50-90ab-4cde-f012-3456789abcde doc_url: https://docs.endstate.io/errors/chip-not-found '500': description: >- Something went wrong on our end. | Error code | When | | --- | --- | | `internal.error` | An unexpected server error occurred. Retry with exponential backoff and include `request_id` in any support request. | x-error-codes: - internal.error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: internal.error: summary: >- An unexpected server error occurred. Retry with exponential backoff and include `request_id` in any support request. value: error: code: internal.error message: >- An unexpected server error occurred. Retry with exponential backoff and include `request_id` in any support request. request_id: req_8e1a7f50-90ab-4cde-f012-3456789abcde doc_url: https://docs.endstate.io/errors/internal-error security: - ApiKeyBearer: [] components: schemas: CreateTestTapRequest: type: object properties: chip_id: type: string pattern: ^[0-9A-Fa-f]{10}$ description: Identifier of the test chip to generate a tap for. example: ABCDEF0123 count: type: integer minimum: 0 description: >- Optional counter value. Defaults to the next emulated chip counter and reserves it, so each tap returns a new e-value. Explicit counts must be greater than the chip's current highestObservedCount. example: 5 required: - chip_id CreateTestTapResponse: type: object properties: chip_id: type: string example: ABCDEF0123 e: type: string example: C78566198547116F3A715DC1C62AF96F count: type: integer minimum: 0 example: 5 required: - chip_id - e - count ErrorResponse: type: object properties: error: type: object properties: code: anyOf: - $ref: '#/components/schemas/ErrorCode' - type: string description: >- Stable, namespaced error code. The `ErrorCode` catalogue lists every code defined today; handle an unrecognized value as a generic failure rather than throwing, since codes are added over time. example: chip.not_found message: type: string description: >- Human-readable description, for logs and debugging. Wording may change without notice - never parse or match against it. example: Chip not found request_id: type: string description: >- Identifier for this request, matching the `X-Request-Id` response header. Log it and include it in any support request. example: req_8e1a7f50-90ab-4cde-f012-3456789abcde doc_url: type: string description: Documentation page for this error code. example: https://docs.endstate.io/errors/chip-not-found details: $ref: '#/components/schemas/ValidationErrorDetails' required: - code - message - request_id - doc_url required: - error description: >- Every error response, regardless of endpoint or HTTP status, uses this envelope. ErrorCode: type: string enum: - validation.failed - auth.unauthorized - auth.forbidden - session_token.invalid_or_expired - session_token.wrong_chip - not_found.resource - rate_limit.exceeded - chip.not_found - chip.invalid_e_value - chip.already_scanned - quota.exceeded - chip.not_a_test_chip - unit.not_found - unit.already_exists - unit.not_minted - collection.not_found - collection.already_exists - collection.not_active - chip.already_paired - chip.bulk_mixed_collections - chip.bulk_pending - unit.issuance_pending - claim.owner_unknown - claim.already_to_recipient - claim.in_progress - claim.not_found - chip_replacement.locked - chip_replacement.in_progress - chip_replacement.not_found - transfer.owner_unknown - transfer.already_to_recipient - transfer.in_progress - transfer.not_found - idempotency.key_conflict - idempotency.in_progress - internal.error description: >- Stable, namespaced error code in `.` form. Branch on this rather than on `message` or the HTTP status. This is the catalogue as of this spec revision, not a closed set - see `ErrorResponse.error.code`. example: chip.not_found ValidationErrorDetails: type: object properties: formErrors: type: array items: type: string description: Issues that apply to the request as a whole rather than one field. example: [] fieldErrors: type: object additionalProperties: type: array items: type: string description: Validation issues keyed by the field that failed. example: name: - Required required: - formErrors - fieldErrors description: Per-field validation detail. Present only on `validation.failed`. securitySchemes: ApiKeyBearer: type: http scheme: bearer bearerFormat: end_sk description: >- Use `Authorization: Bearer end_sk_*` for partner API keys (e.g. `end_sk_AbCd_example_api_key`). ````