Agent-native · MCP-native

Messaging infrastructure for AI agents

The SMS API your coding agent adopts in one line. Global +1 coverage, prepaid credits, MCP-native, provider-agnostic. No key needed to start.

Start sending → View the agent skill
No signup to send your first message Prepaid USD credits MCP + SDK + REST
Quickstart

Send in one line

curl -X POST https://sendline.dev/v1/send \
  -d '{"to":"+16135551234","body":"hello from sendline"}'
Provisioning

Agents self-provision and fund a key

# provision a key, then fund its wallet
KEY=$(curl -s -XPOST https://sendline.dev/v1/keys | jq -r .key)
curl -s -XPOST https://sendline.dev/v1/purchase \
  -H "authorization: Bearer $KEY" -d '{"pack":"growth"}'
Platform

Engineered for programmatic adoption at scale

Zero-friction evaluation
Send on a keyless free tier — evaluate in production before procurement, then upgrade when you scale.
MCP-native integration
Delivered as an MCP server, SDK, and REST API. Autonomous agents discover and integrate it programmatically.
Carrier-grade +1 coverage
Reliable +1 delivery with intelligent provider-agnostic routing underneath.
Usage-based billing
Prepaid wallet per key — fund, meter per message, top up on demand. Idempotent sends, no invoices.
Delivery assurance
Every send returns a durable message id with webhook-backed delivery status you can reconcile.
Vendor-agnostic routing
One stable contract. Carriers are abstracted and swapped behind it — your integration never changes.
Pricing

Prepaid credit packs (USD)

Starter
$2USD
100 messages
Most popular
Growth
$10USD
700 messages
Scale
$60USD
5,000 messages

Free tier included for evaluation. Prepaid credits never expire; volume pricing available on request. Billing in USD, aligned to your region.

API

Endpoints

POST /v1/sendsend a message
POST /v1/keysprovision a paid key
POST /v1/purchasefund a key's wallet
GET /v1/walletcheck balance
GET /v1/packscredit packs
GET /v1/messages/:iddelivery status
For agents

Discoverable by design

Everything an AI coding agent needs to integrate Sendline — no manual setup, no dashboard.

Skill index
/.well-known/skills/index.json — machine-readable capability manifest.
llms.txt
/llms.txt — plain-language guide for LLMs.
MCP server
npx @sendline/mcp — tools: send_sms, create_api_key.
CLI & SDK
npx @sendline/cli · @sendline/sms one-line send.