Start with a little context.
An appointment, order, or support request gives the conversation a useful beginning.
Voice API & SIP Trunking
Voice API & SIP.
Make the right connection.
Route incoming calls with sequences or connect your phone system over SIP. Keep numbers, recordings and call outcomes connected to your customer workflow.
f.CALL CONNECTED · EXAMPLE
Fieldnotes Studio
00:24
1 Studio visits · 2 Orders · 3 Support
Your call flow01
AnswerYour application welcomes the caller.
✓02
Collect a choiceKeypad input: 1
✓03
Route the callStudio visits team
↗Connected to Studio visits
Keep your phone systemSIP / EXISTING INFRASTRUCTUREYour system.
Your system.
A new connection.
01Your PBXExisting extensions & routing
↔02SIP trunkConnection to Bird
↔03Calling networkIncoming & outgoing calls
SIP + application trace · illustrativeExample · no request is madecall_example_fn1042 10:42:00 SIP call initiated 10:42:04 Keypad choice: 1 10:42:05 Studio visits route selected 10:42:09 SIP call answered 10:44:31 Call ended Customer outcome: recorded by your application
Context for the next conversationYOUR CUSTOMER RECORDThe call ends.
The call ends.
The context stays.
- Customer
- Alex Lee
- Team
- Studio visits
- Related visit
- FN–1042
Your application records the resolution and chooses any follow-up message.
Example content and data. Explore the workflow below; nothing is sent or changed in a live account.
Companies that trust Bird across their communications.
A real customer resultVoiceIncident notifications with local caller identificationPagerDuty’s customer story describes Bird Voice and local numbers for incident alerts worldwide.Read PagerDuty’s story
VOICE / TRY IT YOURSELFA small choice.
A small choice.
The right team.
Choose an application route and inspect an answered, busy, unanswered or unknown call. Signaling, caller audio and the business result are separate observations.
CALLER / A USEFUL CHOICE
FN–1042 / CUSTOMER CALLHow can we help?
Check booking FN–1042 in the application. Answered does not prove the request was completed.
ROUTING / CALL RECORD
Incoming number → Bird SIP↓Studio visits↓Connected application → Studio visits team
Illustrative · 18 September 2026 Signaling: SIP connection established Caller audio: Connected media path; no playback Application route: Studio visits Bird record: answered Booking FN–1042: awaiting application confirmation Inspect the final record to review this outcome.Read call outcomes ↗
Interactive illustration · fictional customer and results · no messages are sent
WHAT IT MEANS FOR YOUR CUSTOMERA clear route.
A clear route.
A person who can help.
Make calling part of the customer journey. Give the caller a useful introduction, the right destination, and a follow-up they can keep.
Connect to the right place.
Build prompts and routing into your application, or connect the phone system your team already uses.
Leave something useful behind.
Let your application send a written confirmation or next step through Email or messaging.
FIND YOUR WAY IN
Choose the connection your team needs.
SIP connectivity.
Your PBX or SBC owns extensions and application logic. Bird connects eligible calls after trunk admission, direction and routing are configured.
Prepare SIP setup ↗Application-owned calling.
Connect the application through SIP. You can also publish and run Bird-native sequences from your dashboard.
Plan the application path ↗READY WHEN YOU ARE
A calling plan you can build on.
BUILD WITH VOICEGive every call
Give every call
a clear direction.
Route incoming calls through a published call sequence, or connect your PBX and voice agent over SIP. Follow each call through its events and final record. The examples here show the SIP test and SDK call reads.
The terminal example requires the Bird CLI, baresip, an enabled trunk, a verified caller ID and an enabled destination. It places a real, billed call. Follow the setup guide before running it.
Place your first call ↗Run the terminal quickstart ↗Create session credentials ↗Configure a trunk ↗Connect a SIP client ↗MCP connection ↗
Read the call record guide →Place a test call · CLI and baresipbird voice tools test-call "$VOICE_TO" \
--trunk "$BIRD_TRUNK_ID" \
--caller-id "$BIRD_CALLER_ID" \
--protocol tls \
--duration 30s
bird voice list
THE COMPLETE BIRD PLATFORM
Let the conversation change channels.
A message can become a call. A call can become a clear written follow-up. Connect the moments with Voice, WhatsApp, and Email.
f.
FieldnotesBusiness account
Today · 9:41
Can we move booking FN–1042 to Friday afternoon?
I’ll check with the studio. Your booking details are here.
01
WhatsApp ↗
Alex requests help with booking FN–1042.
AL
A voice. A choice. A connection.Alex LeeStudio visits · Connected to Mia
02
Voice This step
Your application offers a call and routes the question to the studio.
f.
FieldnotesTo: Alex Lee ⌄
Your studio visit. All in one place.
fieldnotes.BOOKING FN–1042Your studio visit.
All in one place.
Alex Lee · Friday, 14:00
Clay workshop · One guest
View your booking ↗
All in one place.
Alex Lee · Friday, 14:00Clay workshop · One guest
View your booking ↗
03
Email ↗
Send the confirmed arrangement after the conversation.
LEARN / BUILD / OPERATEGo further with
FIELD GUIDE
Go further with
Voice.
FIELD GUIDEBuild a phone menu that works.
Create spoken prompts, keypad branches and a testable published sequence.
Read the field guide →01↗02↗03↗04↗05↗06↗07↗08↗09↗10↗11↗
Place your first call
Configure your number, place a test call and inspect the result.
Design a call sequence
Prompts, input, and routing.
Connect SIP trunks
Use your existing voice infrastructure.
Follow call events
Read status without confusing connection with resolution.
Record and review a response
Capture audio, join the transcript and inspect its state.
Voice task library
Find Start, Build, Diagnose, Migrate and Evaluate tasks.
SIP trunk evaluation
Prepare your PBX, network and interoperability checklist.
Launch readiness
Check a controlled call and its independent results.
Number identity
Separate inbound capability from outbound presentation.
Incoming routing
Route to a trunk, forwarding number or call sequence.
Outbound callback
Retain the original attempt when the result is unknown.
Compare call-workflow responsibilities, connection requirements and recovery before choosing your architecture.
VOICE / YOUR CALLING SETUPChoose the connection.
Choose the connection.
Plan the conversation.
Start with supported SIP workspace setup. Confirm number eligibility, interoperability, destinations and capacity with Bird; configure native sequences in the dashboard.
View Voice rates ↗YOUR VOICE SETUPSIP connectivity
Numbers, call legs and handling have distinct charges.
- Calling
- Origin, destination, direction and number type determine rates.
- Rated components
- Number rental, call legs and handling use their own units and increments.
- Evaluation
- Confirm capacity, media compatibility and account access before rollout.
A FEW USEFUL ANSWERS
Voice, answered.
Is this a complete contact centre?
Voice provides numbers, connectivity, and programmable building blocks. The routing, agent experience, and business workflows you need should be scoped with your implementation.
Can I keep my existing PBX?
SIP connectivity is designed to work with an existing phone system. Check compatibility, configuration, destination coverage, and capacity for your deployment.
Should I choose the API or SIP?
Use the API to start a published sequence and follow its call record. Use SIP to connect a PBX or calling application that owns the conversation. Both paths connect the telephone outcome to your customer workflow.
Where do recording requirements belong?
Decide the recording need, customer notice, access, and retention before enabling a supported recording capability. Recording is not implied by making a call.
How do I get started or speak to sales?
Start with a Bird account and follow the setup path on this page. Our sales team can help with migration, volume, or a wider product mix. Start now or talk to sales.