> ## Documentation Index > Fetch the complete documentation index at: https://docs.numi.sh/llms.txt > Use this file to discover all available pages before exploring further. # Start the checkout of the Builder plan > Returns the URL of a Stripe Checkout for the Builder plan. After payment, Stripe sends the browser back to the account page of the numi web app, and the plan changes once Stripe tells the API. ## OpenAPI ````yaml POST /account/checkout openapi: 3.1.0 info: title: numi API version: 0.1.0 summary: Company data for US SEC filers. description: > Segments by XBRL axis (business, product or geography), each axis checked against the revenue that the filing reports, and fundamentals as filed. Every success response has the form `{ "data": ..., "meta": { "request_id": "...", "as_of": "..." } }`, where `as_of` is the time of the response. Every error response has the form `{ "error": { "code": "...", "message": "..." }, "meta": { "request_id": "..." } }`, and some errors have more fields beside `code` and `message`. The `request_id` is also in the `x-request-id` response header. When you write to hello@numi.sh, quote it. servers: - url: https://api.numi.sh/v1 security: - ApiKey: [] - BearerKey: [] paths: /account/checkout: post: summary: Start the checkout of the Builder plan description: >- Returns the URL of a Stripe Checkout for the Builder plan. After payment, Stripe sends the browser back to the account page of the numi web app, and the plan changes once Stripe tells the API. operationId: createCheckout responses: '200': description: The URL to send the browser to. headers: x-request-id: $ref: '#/components/headers/RequestId' content: application/json: schema: type: object required: - data - meta properties: data: type: object required: - url properties: url: type: string format: uri additionalProperties: false meta: $ref: '#/components/schemas/Meta' additionalProperties: false '401': $ref: '#/components/responses/SignInRequired' '409': description: The account is on the Builder plan with a subscription already. headers: x-request-id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' '429': $ref: '#/components/responses/RateLimited' '503': $ref: '#/components/responses/ServiceUnavailable' security: - Session: [] components: headers: RequestId: description: >- The id of the request. It is also in `meta.request_id` of the body. When you write to hello@numi.sh, quote it. schema: $ref: '#/components/schemas/RequestId' schemas: Meta: type: object description: The metadata of one success response. required: - request_id - as_of properties: request_id: $ref: '#/components/schemas/RequestId' as_of: type: string format: date-time description: The time of the response, in UTC. example: '2026-10-19T12:34:56.789Z' additionalProperties: false ErrorEnvelope: type: object description: The body of every error response. required: - error - meta properties: error: $ref: '#/components/schemas/ErrorBody' meta: type: object description: The metadata of one error response. required: - request_id properties: request_id: $ref: '#/components/schemas/RequestId' additionalProperties: false additionalProperties: false RequestId: type: string pattern: ^req_[A-Za-z0-9_-]{16}$ description: The id of one request. example: req_Qm3xYb9Kd2LpR7wA ErrorBody: type: object description: >- The error. Some errors have more fields beside the code and the message. A `rate_limit_exceeded` error has `retry_after` and `scope`, and a `sandbox_restricted` error has `sandbox_companies`, the tickers of the companies that you can read with a sandbox key. required: - code - message properties: code: type: string enum: - unauthorized - invalid_key - rate_limit_exceeded - bad_request - not_found - plan_required - sandbox_restricted - key_limit - conflict - internal_error - service_unavailable description: > A code for programs to branch on. - `unauthorized`: the request has no API key, or an account route has no session. - `invalid_key`: the key is not valid, or it was revoked. - `rate_limit_exceeded`: the account is at the request limit of its plan for the minute or the day, or the IP address is at its limit for the minute. - `bad_request`: a parameter is missing or wrong, or the body is not valid JSON or is too large. - `not_found`: nothing matches the request. - `plan_required`: the plan of the account does not include the endpoint, such as on-demand extraction on the sandbox plan. - `sandbox_restricted`: the request is for a company outside the sandbox, with a sandbox key. - `key_limit`: the account has as many active keys as its plan allows. - `conflict`: a checkout for an account that is on the Builder plan already, or the billing portal for an account with no subscription. - `internal_error`: the server failed. When you write to hello@numi.sh, quote the request id. - `service_unavailable`: the server is not configured for the feature, such as accounts, billing or bulk files. message: type: string description: >- A sentence that says what went wrong and, where it helps, what to do. additionalProperties: true responses: SignInRequired: description: The request has no valid session of the numi web app. headers: x-request-id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: unauthorized message: Sign in to numi to manage your account. meta: request_id: req_Qm3xYb9Kd2LpR7wA RateLimited: description: >- The account is at the request limit of its plan for the minute or the day, or the IP address is at its limit for the minute. Wait the number of seconds in the `Retry-After` header. `scope` is `minute` or `day`, for the limit that was reached. headers: x-request-id: $ref: '#/components/headers/RequestId' Retry-After: description: The number of seconds to wait before the next request. schema: type: integer minimum: 1 example: 12 content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: rate_limit_exceeded message: >- The sandbox plan has a limit of 20 requests a minute. Retry in 12 seconds. retry_after: 12 scope: minute meta: request_id: req_Qm3xYb9Kd2LpR7wA ServiceUnavailable: description: >- The server is not configured for the feature, such as accounts, billing or bulk files. headers: x-request-id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: service_unavailable message: >- Accounts are not configured on this server, so you cannot sign in here. meta: request_id: req_Qm3xYb9Kd2LpR7wA securitySchemes: ApiKey: type: apiKey in: header name: X-API-Key description: A numi API key, sent in the `X-API-Key` header. BearerKey: type: http scheme: bearer description: 'A numi API key, sent as `Authorization: Bearer `.' Session: type: http scheme: bearer description: >- A session of the numi web app, sent as `Authorization: Bearer `. Only the account routes take it. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.