Lockwood
send.co.tz · Messaging platform

Messages that land,
systems that scale.

SMS, WhatsApp, and email from a single API. Transactional messages, marketing broadcasts, and two-way conversations, on one delivery pipeline that reports back in under 200ms.

Start a campaign →API docs
2.4M
Messages this month
99.2%
Delivery rate
148ms
p50 API latency
Principles

Four principles. One delivery standard.

01
Deliverability first

Every component surfaces status. Never hide a failed send behind a success screen.

02
Dense, not cramped

8px base, 12px row gutter. Tabular numbers everywhere throughput is shown.

03
Quiet motion

Signals pulse; content doesn't. Reserve motion for live state — sending, delivered, failed.

04
Receipt-grade copy

Plain verbs. Specific numbers. Never “optimised”, always “sent to 2,482”.

Channels

Three channels. One unified developer experience.

Reach anyone, instantly
SMS

Direct routes to every Tanzanian and East African MNO. OTPs, transactional alerts, payment confirmations, and emergency broadcasts. Sender ID supported, fast throughput.

Conversations that convert
WhatsApp

Send template messages and conversation flows on WhatsApp Cloud API. Approved templates, two-way replies, media support, on the channel your customers already use.

Transactional & marketing
Email

Receipts, password resets, account alerts, newsletters, lifecycle campaigns. Custom domains, DKIM/SPF, per-message analytics.

Platform

Everything you need to message customers, securely and reliably.

01 / 06
One API, every channel

A single REST API to send across SMS, WhatsApp, and email. Same payload, smart channel routing, automatic fallback when a channel fails.

02 / 06
Templates & campaigns

Reusable templates with variables, scheduled broadcasts, contact lists, segments, and A/B tests. Built for marketing and ops in equal measure.

03 / 06
Delivery analytics

Real-time delivery, open, and click reports per channel. p50 API latency under 200ms. Webhooks deliver status updates straight into your stack.

04 / 06
Compliant by default

Sender ID approval, opt-out keywords, DPA-grade logging, GDPR-aligned data residency. Built for regulated senders and serious volume.

05 / 06
Two-way conversations

WhatsApp inbox with team assignment, canned replies, and webhook routing. Hand off to your support tool or chatbot, or reply right inside the dashboard.

06 / 06
SDKs & docs

Node, Python, PHP, Go SDKs. OpenAPI spec, postman collection, and runnable examples. Get to your first send in under five minutes.

Built for throughput

Compose, send, follow up. Without leaving the thread.

Conversation thread
Hi Maya — your seedling kit ships Monday. Track it at lockwd.co/trk/4482.
Perfect — can I get a second kit sent to my mum's address?
Done — second kit on the way. Confirmation sent to +255 658 ••• 291.
LiveQueuedDelivered · 2,412Failed · 12
Compose
Audience · active customers (2,482)
Hi {first_name} — your order {order_id} is on its way. Track at lockwd.co/trk/{id}
74 / 160 chars · 1 segment
2.4M
Messages this month
99.2%
Delivery rate
148ms
p50 API latency
Live
4 campaigns sending
Developer-first

One REST call. Every message you need.

Use the same JSON payload across SMS, WhatsApp, and email. Smart channel routing falls back automatically. Webhooks deliver status updates straight to your service.

REST APIWebhooksNode SDKPython SDKPHP SDKGo SDKOpenAPI
POST /v1/messages
{
  "channel": "auto",     // sms | whatsapp | email | auto
  "to": "+255712345678",
  "from": "Malipopay",
  "template": "otp.v2",
  "variables": {
    "code": "428715",
    "minutes": 5
  },
  "fallback": ["whatsapp", "sms"]
}
→ 202 Accepted { "id": "msg_8f12...", "status": "queued", "latency_ms": 148 }
Who it's for

Built for teams that need messages to actually arrive.

Product & engineering

Drop-in REST API and SDKs for SMS OTPs, transactional alerts, and webhooks. Stop juggling three different gateways.

Marketing & growth

Run multi-channel campaigns from one dashboard. Build lists, test templates, measure delivery and clicks.

Operations & support

Reach customers where they are. Send order updates over WhatsApp, escalate to email, fall back to SMS.

Start sending in minutes. Pay only for what lands.

Start a campaign →Talk to sales