AI Phone Calls with StablePhone

https://stablephone.dev

Setup

Quick Reference

https://stablephone.dev/api/call

GET https://stablephone.dev/api/call/{call_id}

https://stablephone.dev/api/number

https://stablephone.dev/api/number/topup

GET https://stablephone.dev/api/numbers?wallet=0x...

Make a Call

npx agentcash fetch https://stablephone.dev/api/call -m POST -b '{
  "phone_number": "+14155551234",
  "task": "Call this person and ask if they are available for a meeting tomorrow at 2pm. Be polite and professional."
}'

• phone_number

  — E.164 format (e.g.

  +14155551234

  )

• task

  — instructions for the AI agent (what to say, how to behave)

• from

  — outbound caller ID (must be an active StablePhone number)

• first_sentence

  — specific opening line

• voice

  — voice preset (see Voice Options below)

• max_duration

  — max call length in minutes (1-30, default 5)

• wait_for_greeting

  — wait for recipient to speak first (default false)

• record

  — record call audio (default true)

• model

  —

  "base"

  (default, best quality) or

  "turbo"

  (lowest latency)

• transfer_phone_number

  — number to transfer to if caller requests a human

• voicemail_action

  —

  "hangup"

  (default),

  "leave_message"

  , or

  "ignore"

• voicemail_message

  — message to leave (required when action is

  "leave_message"

  )

• metadata

  — custom key-value data to attach

Check Call Status

completed

npx agentcash fetch https://stablephone.dev/api/call/{call_id}

• status

  — call status

• completed

  — boolean, true when call is done

• answered_by

  —

  "human"

  ,

  "voicemail"

  , or

  "no_answer"

• call_length

  — duration in seconds

• summary

  — AI-generated call summary

• transcript

  — full text transcript

• transcripts

  — array of timestamped transcript segments

• recording_url

  — URL to call recording

• price

  — actual cost

max_duration

Voice Options

nat

josh

maya

june

paige

derek

florian

Buy a Phone Number

npx agentcash fetch https://stablephone.dev/api/number -m POST -b '{"area_code": "415", "country_code": "US"}'

• area_code

  — 3-digit US/CA area code (random if omitted)

• country_code

  —

  "US"

  (default) or

  "CA"

Top Up a Number

npx agentcash fetch https://stablephone.dev/api/number/topup -m POST -b '{"phone_number": "+14155551234"}'

List Your Numbers

npx agentcash fetch https://stablephone.dev/api/numbers?wallet=YOUR_WALLET_ADDRESS

Workflows

Quick Call

• (Optional) Check balance:

  npx agentcash wallet info

• Make call with task instructions
• Poll status until completed
• Review transcript and summary

npx agentcash fetch https://stablephone.dev/api/call -m POST -b '{
  "phone_number": "+14155551234",
  "task": "Ask if the business is open on weekends and what their hours are."
}'

Leave a Voicemail

npx agentcash fetch https://stablephone.dev/api/call -m POST -b '{
  "phone_number": "+14155551234",
  "task": "Leave a voicemail about the appointment.",
  "voicemail_action": "leave_message",
  "voicemail_message": "Hi, this is a reminder about your appointment tomorrow at 3pm. Please call back to confirm."
}'

"voicemail_action": "ignore"

Call with Transfer

npx agentcash fetch https://stablephone.dev/api/call -m POST -b '{
  "phone_number": "+14155551234",
  "task": "Qualify this lead. Ask about their budget and timeline. If they are interested, offer to transfer to a sales rep.",
  "transfer_phone_number": "+14155559999",
  "voice": "josh",
  "max_duration": 10
}'

Set Up Dedicated Number

• Buy a phone number ($20)
• Use it as caller ID for outbound calls
• Top up before expiry ($15/30 days)

npx agentcash fetch https://stablephone.dev/api/number -m POST -b '{"area_code": "212", "country_code": "US"}'

from

npx agentcash fetch https://stablephone.dev/api/call -m POST -b '{
  "phone_number": "+14155551234",
  "from": "+12125551234",
  "task": "Confirm the reservation for Friday at 7pm."
}'

Cost Estimation