Contiguity review

Contiguity is a multi-channel communications API — SMS, email, WhatsApp, voice and OTP verification — that added iMessage as an extra capability. The headline pricing is aggressive and the free tier is real, which is why it surfaces in cheapest-iMessage-API searches. Read the pricing page carefully, though: the cheap per-message rates are the SMS rates, and iMessage is a separate monthly capability added to a leased number.

What it is good at

• +One vendor and one API for iMessage, SMS, email, WhatsApp, voice and OTP — the widest channel spread of anything here.
• +Genuinely cheap on every channel that is not iMessage, with a free tier you can build against before paying.
• +No A2P 10DLC registration bureaucracy.
• +No minimums and no hidden carrier or international surcharges on the SMS side.
• +Sensible if iMessage is one channel in a wider system rather than the whole point of it.

Where it will bite you

• −**The cheap number everyone quotes is the SMS price.** iMessage is $69.99/mo as an add-on capability on top of a leased number — mid-range for the category, not the bargain the headline implies.
• −The iMessage documentation is thin next to the SMS documentation; capability detail is hard to confirm before signing up.
• −No CRM integrations at all, so non-engineers have nothing to work in.
• −Fraud detection in place of identity verification is a product posture, not a compliance artefact — do not present it as one in a security review.

What Contiguity claims

Reported as the vendor's own marketing claims. We have not independently reproduced these numbers, and neither should you treat them as benchmarks.

• “Send blue bubbles to over 1.5 billion users in 170+ countries
• “Enterprise-level reliability and scale at hobby-level pricing

The shape of the API

Illustrative — parameter names and endpoints change. Treat this as the flavour of the integration, and copy the real thing from the official docs.

# The iMessage capability must be enabled on a leased number first.
curl -X POST https://api.contiguity.com/send/imessage \
  -H "Authorization: Token $CONTIGUITY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "+15551234567",
    "message": "Table for 4 confirmed: https://acme.co/r/220?utm_source=imessage&utm_medium=imessage&utm_campaign=reservation"
  }'

Tracking links with Contiguity

Whatever you send with, build the URL from one helper so tagging is consistent across every job and campaign. Open the UTM builder to generate one now.