> ## 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. # sms.settings.set > Changes SMS settings for this environment; keys not mentioned are left alone. Quiet hours hold marketing texts until the window opens in the recipient's local time rather than dropping them; times are 24-hour HH:MM and the window may wrap midnight, and setting timezone to null clears it, which stops marketing sends while quiet hours are enabled. keywordReplies set what Lath texts back to STOP, HELP and START — null for each means Lath says nothing, which is the default because the carrier answers these itself unless its own automatic opt-out handling is turned off. Setting one without turning that off sends the person two replies. {{project}} is the only variable, and a reply is billed as the segment it is. ## OpenAPI ````yaml /api-reference/openapi.json post /sms/settings/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: /sms/settings/set: post: tags: - sms summary: sms.settings.set description: >- Changes SMS settings for this environment; keys not mentioned are left alone. Quiet hours hold marketing texts until the window opens in the recipient's local time rather than dropping them; times are 24-hour HH:MM and the window may wrap midnight, and setting timezone to null clears it, which stops marketing sends while quiet hours are enabled. keywordReplies set what Lath texts back to STOP, HELP and START — null for each means Lath says nothing, which is the default because the carrier answers these itself unless its own automatic opt-out handling is turned off. Setting one without turning that off sends the person two replies. {{project}} is the only variable, and a reply is billed as the segment it is. operationId: sms.settings.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: quietHours: type: object properties: enabled: type: boolean start: description: When quiet begins, local 24-hour HH:MM, e.g. 21:00 type: string end: description: When quiet ends, local 24-hour HH:MM, e.g. 08:00 type: string timezone: description: >- IANA zone for contacts whose own is unknown, e.g. America/Los_Angeles. null clears it, which stops marketing sends while quiet hours are on. type: - string - 'null' additionalProperties: false keywordReplies: type: object properties: stop: anyOf: - type: string maxLength: 300 - type: 'null' help: anyOf: - type: string maxLength: 300 - type: 'null' start: anyOf: - type: string maxLength: 300 - type: 'null' additionalProperties: false 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: $schema: https://json-schema.org/draft/2020-12/schema type: object properties: settings: type: object properties: quietHours: type: object properties: enabled: type: boolean start: type: string end: type: string timezone: type: - string - 'null' required: - enabled - start - end - timezone additionalProperties: {} keywordReplies: type: object properties: stop: type: - string - 'null' help: type: - string - 'null' start: type: - string - 'null' required: - stop - help - start additionalProperties: {} required: - quietHours - keywordReplies additionalProperties: {} updatedAt: type: string format: date-time pattern: >- ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d:[0-5]\d(?:\.\d+)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$ required: - settings - updatedAt 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. ````