We hooked up with Respond.io because on paper it had everything we needed. WhatsApp business messages, calls, VoIP, SMS, the automations. Turns out the SMS part was more of a suggestion.
You can't send an SMS longer than 153 chars through their API. It doesn't split it for you, it just rejects it. So now I have to chop up my own messages and send each part separately, and the customer gets like 6 texts instead of one.
I thought that we can use their UI instead, as on your side long text still looks like one single SMS. Turns out it's even worse. Underneath they hack it into pieces at completely random points, sometimes mid word, and deliver it as separate messages. The customer gets "Your appointment is confir" and then "med for Tue".
They also don't guarantee the order. Message gets split into 6 parts and the customer receives them as 1, 3, 5, 4, 2, 6. My customers are basically solving a word puzzle to figure out when their appointment is. Makes no fucking sense for a platform with SMS in its literal marketing.
I dug into it and Respond.io uses Telnyx as their SMS provider. Concatenated SMS has been a solved problem since roughly the Nokia 3310, and Telnyx supports it out of the box. Send Telnyx a long message through their API directly and it splits it properly, the phone stitches it back together, customer sees one message, parts = 6. Tested it myself, works exactly as expected.
Respond.io instead chops the message up themselves and sends each chunk to Telnyx as a completely separate standalone SMS. So obviously they arrive as separate messages, in whatever order the network feels like. They took a provider that handles this correctly and built a layer on top that breaks it.
Here's what the Telnyx delivery report looks like for the exact same ~900 char message sent both ways (content swapped for an example, structure is 1:1 with my real log):
Sent directly through Telnyx:
| Sent | Delivered | Parts | Body |
| 16:05:21 | 16:05:35 | 6 | Reminder: your car is booked for a full service tomorrow at 8:30 AM. [...] see you tomorrow! |
One row. One message. Customer sees one text. Revolutionary stuff.
Same message sent from the Respond.io UI, shown in the order the customer's phone received it:
| Sent | Delivered | Parts | Body |
| 16:16:27 | 16:16:29 | 1 | hours depending on the queue. We will call you first if we find anything unexpected before doing any additional work, so there are no surprise costs. Y |
| 16:16:30 | 16:16:31 | 1 | lease reply to this message by 7 PM today and we will have one ready for you in the morning. Thank you for choosing us and see you tomorrow! |
| 16:16:27 | 16:16:32 | 1 | e receptionist at the front desk. The inspection covers brakes, oil and filters, coolant, tyres, battery and the AC system, and it usually takes about 4 |
| 16:16:28 | 16:16:32 | 1 | Reminder: your car is booked for a full service tomorrow at 8:30 AM. Please drop it off at the rear entrance on Garden Street and leave the keys with th |
| 16:16:29 | 16:16:33 | 1 | valuables from the cabin and the boot, and note that the workshop entrance gate stays closed until 8 AM sharp. If you need a courtesy car for the day p |
| 16:16:29 | 16:16:33 | 1 | ou can pick the car up any time before 6 PM, the invoice will be sent to your email and can be paid online or at the desk. Please remember to remove any |
I'm so done with them at this point. Anyone have personal recommendations for something that actually works with:
- API
- WhatsApp Messages + Calls
- VoIP
- SMS (that arrives whole, in order)
Would take any suggestions.