> ## Documentation Index > Fetch the complete documentation index at: https://docs.trylath.com/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Every Lath operation is POST https://platform.trylath.com/, with a JSON body and `Authorization: Bearer `. `email.send` is POST /email/send. > Branch on `error.code`, never on `error.message`. Every refusal also carries `error.fix`, which names the next step. > Send an `Idempotency-Key` header on any operation that is not retry-safe, so a retry cannot run it twice. > A `lath_test_` key emails only the account's own members and sends no SMS; a `lath_live_` key reaches real recipients and is billed. > The OpenAPI document, generated from the same registry as the routes, is at https://platform.trylath.com/openapi.json. # billing.profile.set > Sets who this account's invoices are made out to. Send only the fields to change; null or an empty string clears one. The address is replaced as a whole when given. A tax ID is its kind and number together (for example eu_vat and DE123456789), printed on invoices as given — it is not checked with any tax authority. Shown on invoices from Lath; not yet sent to the payment processor. ## OpenAPI ````yaml /api-reference/openapi.json post /billing/profile/set openapi: 3.1.0 info: title: Lath API version: 0.1.0 description: >- Every operation is one POST. The same set is reachable over MCP, the SDK and the CLI; nothing is dashboard-only. servers: - url: https://platform.trylath.com description: This deployment security: [] paths: /billing/profile/set: post: tags: - billing summary: billing.profile.set description: >- Sets who this account's invoices are made out to. Send only the fields to change; null or an empty string clears one. The address is replaced as a whole when given. A tax ID is its kind and number together (for example eu_vat and DE123456789), printed on invoices as given — it is not checked with any tax authority. Shown on invoices from Lath; not yet sent to the payment processor. operationId: billing.profile.set parameters: - name: Idempotency-Key in: header required: false schema: type: string description: >- Replays the stored response for the same key and input; refuses different input. requestBody: required: true content: application/json: schema: $schema: https://json-schema.org/draft/2020-12/schema type: object properties: email: anyOf: - type: - string - 'null' - type: string const: '' legalName: anyOf: - type: string maxLength: 200 - type: 'null' address: anyOf: - type: object properties: line1: anyOf: - type: string maxLength: 200 - type: 'null' line2: anyOf: - type: string maxLength: 200 - type: 'null' city: anyOf: - type: string maxLength: 120 - type: 'null' region: anyOf: - type: string maxLength: 120 - type: 'null' postalCode: anyOf: - type: string maxLength: 32 - type: 'null' country: anyOf: - anyOf: - type: string pattern: ^[A-Za-z]{2}$ - type: 'null' - type: string const: '' additionalProperties: false - type: 'null' taxId: anyOf: - type: object properties: type: type: string enum: - eu_vat - gb_vat - ch_vat - no_vat - au_abn - ca_bn - ca_gst_hst - in_gst - us_ein - other value: type: string minLength: 2 maxLength: 40 pattern: ^[A-Za-z0-9 .\-/]+$ required: - type - value additionalProperties: false - type: 'null' additionalProperties: false responses: '200': description: '{ activityId, result }. activityId is empty for reads.' content: application/json: schema: type: object properties: activityId: type: string description: The activity this call created, or empty for a read. result: $schema: https://json-schema.org/draft/2020-12/schema type: object properties: accountId: type: string format: uuid pattern: >- ^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$ profile: type: object properties: email: type: - string - 'null' legalName: type: - string - 'null' address: type: object properties: line1: type: - string - 'null' line2: type: - string - 'null' city: type: - string - 'null' region: type: - string - 'null' postalCode: type: - string - 'null' country: type: - string - 'null' required: - line1 - line2 - city - region - postalCode - country additionalProperties: {} taxId: anyOf: - type: object properties: type: type: string enum: - eu_vat - gb_vat - ch_vat - no_vat - au_abn - ca_bn - ca_gst_hst - in_gst - us_ein - other value: type: string required: - type - value additionalProperties: {} - type: 'null' updatedAt: anyOf: - type: string format: date-time pattern: >- ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d:[0-5]\d(?:\.\d+)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$ - type: 'null' required: - email - legalName - address - taxId - updatedAt additionalProperties: {} required: - accountId - profile additionalProperties: {} required: - activityId - result '400': description: invalid_input or invalid_json '401': description: unauthenticated '403': description: forbidden '404': description: not_found '409': description: 'conflict: idempotency_mismatch, email_taken, last_key' '413': description: body_too_large '429': description: rate_limited security: - bearer: [] components: securitySchemes: bearer: type: http scheme: bearer description: >- A Lath API key: lath_live_sk… or lath_test_sk… on a server, lath_live_pk… or lath_test_pk… in a browser. ````