Hi Vapi Team, We are currently using Vapi under the Usage Based “Pay As You Go” plan, and our current concurrency limit is 10 simultaneous calls. We are preparing for a production rollout and would like to understand the best pricing model and upgrade options available for our expected scale. Could you please confirm the following: 1. Concurrency Upgrade Pricing What is the cost difference between concurrency 50 vs concurrency 100? Is concurrency billed as a fixed monthly platform fee, or does it impact per-minute pricing? 2. Pay-As-You-Go Concurrency Upgrade Confirmation Can we increase concurrency (ex: 50 / 100) while staying on the Usage Based Pay-As-You-Go plan? If yes, what is the process and timeline to enable this upgrade? 3. Bundled Minutes Recommendation For a production launch, what bundled minutes would you recommend requesting initially (based on similar deployments)? Are bundled minutes mandatory for higher concurrency, or can we continue purely on usage-based billing? 4. Overage Cost Model Once bundled minutes are consumed, what is the overage billing model? What is the per-minute overage rate? Are there any additional charges beyond minutes (ex: STT/TTS/LLM usage), and how are those billed? If possible, please share a pricing breakdown or quote for both scenarios: Concurrency 50 Concurrency 100 This will help us finalize the best plan for production and align expectations with our client.

Subject: Re: Concurrency Upgrade & Pricing Questions Hi, Happy to answer these: 1. Concurrency pricing is a fixed monthly add-on at $10/line/month. Concurrency 50 = +$400/month, Concurrency 100 = +$900/month (on top of your base plan). It does not affect per-minute rates. 2. Yes, you can upgrade concurrency while staying on Pay-As-You-Go. You can do it self-serve via Dashboard → Settings → Billing → Reserved Concurrency. It takes effect immediately. 3. Not mandatory - you can stay purely on usage-based billing. For production, bundled minutes make sense if you have predictable volume, but there's no requirement to purchase them for higher concurrency. 4. On Pay-As-You-Go, you're billed per minute of usage (~$0.05/min Vapi fee). STT, TTS, and LLM are billed separately based on the providers you use. There are no surprise overage tiers - you just pay for what you use. If your volume is large (50k+ minutes/month), it may be worth reaching out about a custom plan for better rates. Best, Shaunak Vapi Support

Thank you for your reply. How can I track the concurrency usage from Athena? Then Only I can know do I need to increase the limit or not. Let me know is there any way to do it.

Hi Mubashir, You can monitor historical concurrency usage using the Analytics API, specifically by querying the subscription table for the concurrency metric. Here’s an example request:

curl 'https://api.vapi.ai/analytics' \
  -H 'authorization: Bearer {VAPI-PRIVATE-TOKEN}' \
  -H 'content-type: application/json' \
  --data-raw '{
    "queries": [{
      "name": "Number of Concurrent Calls",
      "table": "subscription",
      "timeRange": {
        "start": "2025-10-16T18:30:00.000Z",
        "end": "2025-11-17T05:31:10.184Z",
        "step": "day"
      },
      "operations": [{
        "operation": "max",
        "column": "concurrency",
        "alias": "concurrency"
      }]
    }]
  }'

This will return the maximum concurrency reached per time interval (day in this example). You can adjust the timeRange.step field to: • "hour" → to analyze peak usage within a day • "day" → to review daily peaks • "week" → to evaluate broader trends If you notice your peak concurrency getting close to your current limit (10), that’s a strong signal you may want to increase reserved concurrency before production rollout. Typical best practice: • Check hourly peaks during campaign launches or traffic spikes. • Upgrade when you consistently hit ~70–80% of your limit to avoid call rejections. Thanks