Amazon Chime SDK PSTN Audio review
A focused AWS building block for developers creating programmable PSTN call flows.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Amazon Chime SDK PSTN Audio is an API service for developers building serverless telephony applications on AWS. It supports inbound calls on provisioned DID/DDI and toll-free numbers, outbound calls to landline and mobile numbers in over 100 countries, and phone-number porting. AWS developers can use it for custom IVR systems, notifications, meeting access, call routing, and other workflows where call behavior is controlled programmatically rather than through a conventional visual phone system.
Its strongest fit is the AWS ecosystem. AWS Lambda controls call flows, while Amazon Chime SDK Voice Connector can route calls to PSTN or SIP endpoints. The service also integrates with Amazon S3 and Amazon Transcribe, supporting storage and transcription workflows alongside call handling. DTMF collection, voice prompts, call bridging, on-demand recording by call leg, and Voice Focus noise suppression cover the core building blocks for custom voice applications. Developers can work across languages including JavaScript, Swift, Objective-C, Kotlin, Java, C++, Go, .NET, PHP, Python, Ruby, and Rust.
Pricing is usage-based rather than organized around fixed monthly plans. Costs can include calling, PSTN Audio application usage, phone-number rental, AWS Lambda, and optional meeting or transcription services, so the overall bill depends on the architecture and traffic pattern. The default SIP Media Application Active Call Count quota is 10 concurrent calls per AWS Region and can be adjusted. Choose PSTN Audio when AWS-native control and programmable call logic matter more than a ready-made phone interface. Teams seeking a packaged business calling product or minimal development effort should consider a different category of tool.
Amazon Chime SDK PSTN Audio pros and cons
- Where it wins
- Inbound and outbound calling with provisioned and toll-free numbers
- Lambda-controlled flows with DTMF, prompts, routing, and bridging
- Recording, noise suppression, and integrations across AWS services
- Where it doesn't
- API-only coverage requires development work for end-user applications
- Usage-based billing spans calling, phone numbers, and connected AWS services
- The default regional active-call quota is 10 concurrent calls
Amazon Chime SDK PSTN Audio fact sheet, pricing and score →
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