DIALTONE Handshake

DIALTONE v1 is a spoken handshake plus an attestation rule for phone calls where both ends may be AI agents. It has two halves:

• Caller side: a CALL-E task that opens with a spoken token and switches mode depending on who answers.
• Inbound side: three system-prompt sentences that let a voicebot acknowledge the token.

The runnable reference implementation is apps/python/dialtone. It includes detection, the attestation gate, an honest evaluation and a demo.

When To Use

• You place calls with CALL-E to businesses that may answer with a voicebot.
• You operate an inbound voicebot and want automated callers to finish faster and more honestly.
• Your workflow treats task_completed: true as a commitment: bookings, cancellations, refunds, payments or reschedules.

When Not To Use

• As authentication. The nonce proves an acknowledgement answers this call, not who operates the agent.
• To skip disclosure. The token is spoken after the AI disclosure, never instead of it.
• For emergency, medical, legal or financial decisions. An agent_asserted result is not sufficient evidence for these.

Protocol

1. Caller opening, after the disclosure, with a fresh 3-digit nonce per call:

Hi, I'm an AI assistant calling on behalf of Jordan Lee. Dialtone one, code four seven two.

2. Acknowledgement from a DIALTONE-aware voicebot:

Dialtone one acknowledged, code four seven two. Automated agent. Human review: no.

3. Mode. Pick one based on who answered:

Who answered	Mode	Style
Acknowledged, or clearly an automated agent	MACHINE	field: value sentences; ask only for outcome, confirmation code, and human review
Phone menu	MENU	Navigate with keypad tones or short options
Otherwise, or unsure	HUMAN	Full disclosure, natural pace

4. Attestation. Label every result by who confirmed it:

Label	Who confirmed	Counts as task completed?
human_attested	A person, with high detector confidence	Yes
system_asserted	A phone system read back a record	Yes
agent_asserted	An AI agent: information, or a commitment with a verifiable artifact	Yes
refused	An AI agent confirmed a binding commitment with no artifact	No
unverified	Nothing confirmed, or the counterpart is uncertain	No

The gate never upgrades CALL-E's task_completed; it can only downgrade it.

Inbound Voicebot Adoption

Add to the voicebot's system prompt:

1. If a caller says "dialtone one" followed by "code" and three digits, reply exactly: "Dialtone one acknowledged, code . Automated agent. Human review: ."
2. After that, answer in short "field: value" sentences with no pleasantries.
3. State "Human review" truthfully. Never confirm a booking without a confirmation code.

Implementation

With the app in apps/python/dialtone:

dialtone preview --to +14155550123 --goal "Book a table for two on Friday at 7 PM" --principal "Jordan Lee"
dialtone classify transcript.json
dialtone eval

• dialtone preview prints the compiled CALL-E request and dials nothing.
• A real call requires dialtone call ... --live plus a typed confirmation.

Side Effects And Cancellation

• Preview and classify: no side effects.
• Live calls: place one real outbound phone call each, billed to the CALL-E account. There is no recurring schedule; stopping the local wait does not cancel a call that is already dialling.

References

• Read references/safety.md before placing live calls.
• See references/examples.md for worked handshake and attestation examples.