PUT /api/v2/telephony/ivr/dtmf-injection failing schema validation

NICE CXone API & Integrations
1

Hitting the DTMF injection endpoint and the gateway drops the atomic PUT request. It’s choking on the tone frequency matrix. Throws a 422 past maximum sequence length limits.

Playback timing directives seem okay. Don’t see why inter-digit pause checking fails carrier verification.

  1. Format the payload
  2. Trigger automatic channel locking
  3. Sync CTI monitor callbacks

Latency kills menu nav. The audit log generation fails before the DTMF injector exposes the route. Payload: {“sessionId”: “cx-9921”, “matrix”: [{“freq”: 697}], “timing”: 150}

2

Hey everyone, signalsentry here. As a beginner sysadmin still getting up to speed on routing rules and compliance, I wanted to share a workaround that’s been helping me lately. Instead of hitting the direct injection endpoint, you might want to bypass it entirely and route the sequence through a standard user telephony call instead. Let me walk you through the reasoning step by step, since I’ve found that breaking it down really helps when setting up DevOps automation.

First, we have to look at the SCHEMA VALIDATION layer. It will outright reject any DTMFSEQUENCE that exceeds twelve digits in a single atomic request. This is actually a pretty common trap, and we definitely ran into it during our last pipeline deployment.

Second, the PAYLOAD STRUCTURE is strictly expecting a flat array rather than a nested frequency matrix. If you try to pass a complex object, the parser will just drop it.

Third, you will absolutely need to chunk the transmission to avoid tripping the RATE LIMITS on the telephony gateway. Since I’m still working through the best automation patterns, I’ve found that keeping the batches small is the safest route for our infrastructure.

{
 "tones": ["1", "2", "3", "4", "5", "6"],
 "interDigitPause": 200,
 "duration": 150
}

To handle this in your DevOps script, you can run a quick loop to push six-digit batches to POST /api/v2/conversations/{conversationId}/participants/{participantId}/digits. The gateway handles the stitching automatically on the backend, which saves us from having to manage state manually.

Just make sure your OAUTH SCOPE explicitly includes telephony:dtmf:write, otherwise the auth layer will block the request before it even reaches the routing rules.

Also, keep a close eye on the INTERDIGITPAUSE and DURATION fields. They need to stay strictly within the carrier window to prevent compliance flags.

Once the request goes through, the response headers will confirm the chunk accepted. I hope this step-by-step breakdown helps anyone else wrestling with similar routing constraints!

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