Build on SendLynx

List services with their variants and add-ons.

Retrieve a single service.

Create a service. Money is in integer cents. paymentMode defaults to 'deposit' when a deposit is set, else 'in_person'.

{
  "name": "Men's Haircut",
  "description": "Classic cut and style.",
  "durationMin": 30,
  "priceCents": 5000,
  "depositCents": 1000,
  "paymentMode": "deposit",
  "bufferMin": 5,
  "active": true,
  "rebookEnabled": true,
  "rebookIntervalDays": 28
}

Update a service. Send only the fields you want to change.

{
  "priceCents": 5500,
  "active": true
}

Delete a service. Fails with 409 if it has bookings. Deactivate it (PATCH active:false) instead to keep its history.

List team members (optionally filtered to a service).

Create a provider (owner/admin). Enforces your plan's provider cap and seeds default Mon–Fri 9–5 hours. Pass serviceIds to set which services they offer.

{
  "name": "Jordan Smith",
  "email": "jordan@example.com",
  "bio": "Senior stylist",
  "active": true,
  "serviceIds": []
}

Update a provider (owner/admin). Send only the fields you want to change; serviceIds replaces their service assignments.

{
  "name": "Jordan A. Smith",
  "active": true
}

Delete a provider (owner/admin). Fails with 409 if they have bookings. Deactivate them (PATCH active:false) instead to keep history.

Open appointment slots per day across a date range (max 14 days). For a multi-service session pass additionalServiceIds: slots are sized to the merged duration and only providers who offer EVERY selected service are considered (so the slots are bookable with the same combo via POST /bookings).

When your team's connected personal calendars (Google) are busy, for a window of up to 45 days, so nothing gets booked over them. Integrations and assistants see each block as "Busy" with its start and end only; event titles are shown only inside the SendLynx apps. Providers whose calendar could not be read are listed in `unreadable`.

List bookings, newest first.

Create an appointment. customer.email OR customer.phone is required (a phone-only customer gets a synthetic address).

smsConsent is a LEGAL CONSENT ASSERTION, not a message toggle: pass true ONLY when your application has captured the customer's express consent to receive appointment texts (TCPA). It is recorded durably on the client. When true (with a phone), SendLynx also sends an SMS confirmation. Set notify:false to suppress SendLynx's confirmation (when you send your own). The response carries sms:{sent,reason} so you can see whether the confirmation text went out (e.g. reason:"sms_disabled").

If a deposit is required, returns a depositCheckoutUrl. MULTI-SERVICE: pass additionalServiceIds:[…] to book several services in one appointment. Their duration and price merge into the session, the chosen provider must offer EVERY service (with staffId:"any" only providers who do all of them are considered), and the booking response includes a services[] snapshot ({serviceId,name,durationMin,priceCents}, primary first). variantId applies to the primary service; addOnIds may reference an add-on of ANY service in the session (primary or an additionalServiceId) and each add-on's price + time merges into the totals.

CUSTOM PRICE (first-party app and owner keys, token holder an owner or admin): pass priceCents (whole cents, 0 allowed) to book this visit at that price instead of the computed total, with an optional priceReason (200 chars). The booking's priceCents and balance due follow it, and its timeline records "Price set to $X by <name>: <reason>". Other applications get 403; an AI assistant key books at the listed price.

{
  "serviceId": "REPLACE_WITH_SERVICE_ID",
  "staffId": "any",
  "startUtc": "2026-06-20T15:00:00Z",
  "customer": {
    "name": "Jane Doe",
    "phone": "+15551234567"
  },
  "additionalServiceIds": [],
  "addOnIds": [],
  "smsConsent": true,
  "notify": true,
  "serviceAddress": "12 Main St",
  "notes": "Leaky faucet"
}

Retrieve a single booking.

Reschedule a booking to a new start time.

{
  "startUtc": "2026-06-21T16:00:00Z"
}

Cancel a booking. Money collected on it is refunded, so owners and admins only when it has a payment.

keepDeposit:true is a late cancellation inside the business's cancelCutoffHours where the business keeps the deposit as the fee its cancellation policy names: everything else paid is refunded, and the customer's cancellation email and text say the deposit was kept and quote the policy. Outside the cutoff, with no cutoff, or with no deposit collected, the flag is ignored, the whole ledger is refunded and the response carries a `warnings` entry saying why. The booking's `depositKeptCents` records what was kept.

{
  "reason": "Customer requested",
  "keepDeposit": false
}

Cancel this booking and every upcoming occurrence of its recurring series (each goes through the full cancel path: deposit refund, seat release, calendar + waitlist). Falls back to a single cancel if the booking isn't recurring. Returns { cancelled: <count> }.

Check the client in: sets `arrivedAt` once and adds an "Arrived at 2:05 PM" line to the booking's timeline. The status does not change.

A second call is a no-op (200, same `arrivedAt`). Refused (409 not_modifiable) on a cancelled, completed, no-show or requested booking, and when the start is more than 12 hours away. A team member may check in bookings assigned to their own provider profile only (403 forbidden otherwise).

Collect the balance due on a booking. Owners and admins only, like the dashboard's Collect payment dialog.

method is card | cash | other. cash and other record money taken in person: amountCents goes toward the price, tipCents (0 to 100000) is stored beside it and never counts toward the price or the balance due, and emailReceipt (default true) sends the client a receipt with the service, amount, tip and method; a placeholder address gets none. card returns a payment link: without tipCents it is SendLynx's pay page, where the client adds a tip (none, 15%, 20%, 25% or their own amount) before Stripe Checkout opens; with tipCents the link is the Checkout itself, with the tip as its own line. The webhook marks the booking paid and keeps the tip in payments.tipCents. Deposits take no tip. The response carries url (card), paymentStatus and paymentId (cash/other).

{
  "method": "cash",
  "amountCents": 6000,
  "tipCents": 1000,
  "emailReceipt": true
}

Email the client a payment link for an extra charge on top of the booked price (the job grew). Owners and admins only. Direct charge on the business's connected account; the booking itself is unchanged. tipCents (optional, 0 to 100000) adds a tip the client already agreed to as its own line; it is stored apart from the charge. Returns the link so the app can also show or share it.

{
  "amountCents": 2500,
  "reason": "Extra room",
  "tipCents": 0
}

List customer contacts (each includes phone). Look up by email or phone, or search by name with q.

An email ending in .sendlynx.local (walkin-...@manual.sendlynx.local, 5551234567@phone.sendlynx.local) or in .invalid is a placeholder for a client with no email on file: nothing is ever mailed to it. Clients carry no street address.

Create or update a customer by email (201 if new, 200 if matched).

{
  "name": "Jane Doe",
  "email": "jane@example.com",
  "phone": "+15551234567",
  "smsConsent": false
}

Retrieve a single customer.

Update a customer. Email can be changed (e.g. a phone-only client who later gives a real address); it's the dedup key, so a collision with another client returns 409. smsConsent can only be turned on; pass notes to set the operator note (empty string clears it).

{
  "name": "Jane A. Doe",
  "email": "jane@example.com",
  "phone": "+15559876543",
  "notes": "Prefers morning appointments."
}

Erase a client's personal data (owner/admin), for a "delete my data" request. Upcoming bookings are cancelled and refunded through the normal cancel path, then the client row and every booking, quote, text and mail log for them is scrubbed. Bookings and payments stay as history under "Deleted client". Returns { ok, alreadyErased, cancelledBookings }; a second call is a no-op.

Add a lead (someone who showed interest but hasn't booked) and let SendLynx handle the first touch: a follow-up text with the booking link between 8 AM and 8 PM in the business's timezone (held until morning otherwise), or an email invite when there is no text consent. Text consent is never inferred from the source: pass smsConsent:true only when the form had a text-consent checkbox the person ticked, with its wording as consentText. A Facebook lead posted without smsConsent:true is still created and never texted: with an email the invite goes by email, with a phone alone followUp is { channel: "none", status: "skipped", reason: "no_consent" }; `warnings` says what to pass either way. The owner gets a push and an email with the form's answers. Re-posting the same person (same email or phone) is safe: nothing is re-sent and a booked client is never demoted.

{
  "name": "Maria Alvarez",
  "email": "maria@example.com",
  "phone": "+17045550168",
  "source": "facebook",
  "formName": "Free consult",
  "formId": "1234567890",
  "answers": [
    {
      "question": "What brings you in?",
      "answer": "Lower back pain"
    }
  ],
  "smsConsent": true,
  "consentText": "I agree to receive text messages from At Home Chiropractic about my request.",
  "consentAt": "2026-10-20T14:05:00Z"
}

List deposit/payment records (no raw Stripe ids). Each carries amountCents (the price part), tipCents (a tip beside it, never toward the price), method (card | cash | other), refundedAmountCents (of the price part) and refundedTipCents (a tip handed back with a full refund).

List estimates and invoices, newest first. Each carries its line items, totals in cents, status and amountPaidCents.

Create an estimate or invoice as a draft. Nothing is sent to the customer. Money is integer cents; totals and tax are computed for you.

kind is "estimate" (the default) or "invoice". Each line item has description, quantity (decimals allowed), unitPriceCents, an optional unit label ("hr", "sq ft", up to 16 characters) and taxable (default true; it only matters when taxRateBps is set). taxRateBps is basis points (725 = 7.25%) and applies to taxable lines only. collectOnApproval is none | deposit | full. depositKind defaults to "amount" (depositCents, at least 50 and below the total), so a percent deposit must send depositKind "percent" with depositBps: 30% down is collectOnApproval "deposit", depositKind "percent", depositBps 3000. expiresAt (YYYY-MM-DD) is the valid-until date on an estimate and the due date on an invoice, at the end of that day in the business's timezone; an invoice without one gets the business's default due date when it is sent. Leave terms out to copy in the business's default terms (null when it has none). serviceId is one top-level field, the service the job is for (used when the quote is later booked); line items do not take a serviceId. The EST-/INV- number (docNumber) is assigned when the quote is first sent. customerEmail is required; the customer is matched to (or added as) a client. Each call creates a new draft, so check GET /api/v1/quotes?status=draft for an open draft for the same customer and title first, and ask the owner before making another.

{
  "kind": "estimate",
  "customerName": "Dana Whitfield",
  "customerEmail": "dana@example.com",
  "customerPhone": "+15551234567",
  "title": "Back deck restain",
  "message": "Semi-transparent cedar tone, same as last time.",
  "lineItems": [
    {
      "description": "Deck boards, clean and stain",
      "quantity": 320,
      "unit": "sq ft",
      "unitPriceCents": 350,
      "taxable": true
    },
    {
      "description": "Railing, stain",
      "quantity": 48,
      "unit": "linear ft",
      "unitPriceCents": 600,
      "taxable": true
    },
    {
      "description": "Labor, prep and cleanup",
      "quantity": 3.5,
      "unit": "hr",
      "unitPriceCents": 6500,
      "taxable": false
    }
  ],
  "collectOnApproval": "deposit",
  "depositKind": "percent",
  "depositBps": 2500,
  "serviceAddress": "12 Main St"
}

Retrieve one estimate or invoice, including amountPaidCents (the balance is totalCents minus amountPaidCents).

Replace a draft or sent quote with the body you send. GET it first and send every field back with your changes.

This is a full replacement: customerName, customerEmail, title and lineItems are required, and taxRateBps, expiresAt, serviceAddress, message and the deposit fields are cleared when left out. photos, poNumber and terms are kept when left out (null clears them). Fails with 422 once the customer has approved or paid. AI assistant keys may edit drafts only.

{
  "kind": "estimate",
  "customerName": "Dana Whitfield",
  "customerEmail": "dana@example.com",
  "customerPhone": "+15551234567",
  "title": "Back deck restain",
  "message": "Semi-transparent cedar tone, same as last time.",
  "lineItems": [
    {
      "description": "Deck boards, clean and stain",
      "quantity": 320,
      "unit": "sq ft",
      "unitPriceCents": 350,
      "taxable": true
    },
    {
      "description": "Railing, stain",
      "quantity": 60,
      "unit": "linear ft",
      "unitPriceCents": 600,
      "taxable": true
    },
    {
      "description": "Labor, prep and cleanup",
      "quantity": 3.5,
      "unit": "hr",
      "unitPriceCents": 6500,
      "taxable": false
    }
  ],
  "collectOnApproval": "deposit",
  "depositKind": "percent",
  "depositBps": 2500,
  "serviceAddress": "12 Main St"
}

Delete an unsent draft. A quote that was ever sent, or has a payment, is voided in SendLynx instead (422 here).

The estimate or invoice as a PDF (application/pdf), the same document the customer gets, without their pay link.

Send (or re-send) the quote to the customer by email and/or text. Assigns the EST-/INV- number on first send. Body flags default to email only. Returns 422 delivery_failed when nothing could be delivered. Not available to AI assistant keys (403 assistant_not_allowed).

{
  "email": true,
  "sms": false
}

Create a Stripe payment link for the remaining balance. Returns { data: { url } }. Not available to AI assistant keys (403 assistant_not_allowed).

Schedule an approved quote as a booking with a provider. Returns { data: { bookingId } }. Not available to AI assistant keys (403 assistant_not_allowed).

{
  "staffId": "REPLACE_WITH_STAFF_ID",
  "startUtc": "2026-11-10T14:00:00Z",
  "durationMin": 240
}

Upload a job photo (multipart 'file', image/*) and append it to the quote's photos (max 24). Returns { data: { url } }.

List your webhook subscriptions (signing secrets are never returned).

Subscribe an HTTPS URL to events: booking.created, booking.requested, booking.canceled, booking.rescheduled, payment.received, client.created. Returns the HMAC signing `secret` ONCE. Store it to verify the X-SendLynx-Signature header. 10 consecutive delivery failures auto-disable a subscription.

{
  "url": "https://example.com/webhooks/sendlynx",
  "events": [
    "booking.created",
    "payment.received"
  ]
}

Unsubscribe a webhook (an integration calls this when it's switched off).

A realistic static sample delivery for an event type, shaped exactly like a live webhook POST body.

Two-factor status for your account: { enabled, enabledAt }.

Begin two-factor enrollment. Returns an otpauth keyUri, a QR data URL, and the manual secret. Does not enable 2FA until you confirm.

Confirm enrollment with a live code; enables 2FA and returns the one-time backup codes.

{
  "code": "123456"
}

Disable 2FA after re-proving identity with your password OR a current authenticator code.

{
  "code": "123456"
}

The business's operational config, including smsEnabled (whether SMS confirmations/reminders are turned on), timezone, deposit/notice/cancel policies, and branding.

Partial update of operational settings (owner/admin). Set smsEnabled:true to turn on SMS for a business. New businesses start with it OFF. (SMS still also requires an SMS-capable plan and per-client consent before a text actually sends.)

{
  "smsEnabled": true,
  "notifyOnPayment": true
}

The Activity log (owner/admin), newest first: who changed settings, hours, the team, refunds and kept deposits, integrations, keys and the booking link. Each row has kind, summary, actor, createdAt and an optional targetType/targetId. Returns { data, has_more, next_before }.

Google Calendar status: { connected, googleEmail, available, connectUrl }. Open connectUrl in a browser to connect.

Disconnect Google Calendar for your provider profile.

Upload the business logo (multipart 'file', image/* ≤10MB). Sets logoUrl.

Upload the business cover image (multipart 'file', image/* ≤10MB). Sets coverImageUrl.

SMS allowance + usage this month: { monthlyCap, usedThisMonth, allowanceRemaining, purchasedCreditBalance }. Buying credits is web-only.