Call Recordings

Dual-channel stereo recording with tiered storage and secure playback access.

Every voice call is recorded as a dual-channel stereo file. The caller's audio is captured on one channel; the agent's audio is captured on the other. This separation enables independent analysis of each side - post-call quality scoring can evaluate the agent's delivery separately from the caller's speech.

Recording Format

Channel	Format	Sample Rate	Source
Caller (inbound)	mulaw	8 kHz	Telephony stream
Agent (outbound)	PCM16	16 kHz	Text-to-speech engine output

The two channels are aligned by a shared timeline marker (media_start_epoch_ms) that enables precise synchronization during playback and analysis.

Storage Lifecycle

Recordings move through three storage tiers based on age:

Tier	Age	Access Time	Use Case
Standard	0-3 days	Immediate	Active review, QA, operator playback
Warm Archive	3+ days	Up to 3 hours to restore	Compliance review, incident investigation
Cold Archive	Long-term	Up to 12 hours to restore	Regulatory retention, legal hold

When you request a recording that has been archived, the system returns a 202 response with an estimated restoration time. Once restored, the recording is available via a secure, time-limited URL.

Access

Recordings are accessed through secure, time-limited URLs generated by the Platform API. Each URL is scoped to the requesting workspace and expires after one hour. Metadata includes the call identifier, workspace, direction (inbound/outbound), recording format, sample rate, duration, and byte counts.

For how recordings feed into post-call quality scoring, see Audio Pipeline. For how recording data is used in post-call transcript accuracy measurement, see Performance Characteristics. For the lane-based timeline visualization that synchronizes recordings with agent actions, tool calls, and system events, see Call Playback Timeline.