Agent skill

Dialtone Handshake

by CALLE-AI in CALLE-AI/awesome-phone-call-agents

A skill your agent uses when an AI phone call agent (outbound caller or inbound voicebot) needs to recognise that the other end of the call is also an AI, switch to a compressed machine mode, and…

MITAuto-check passed

Install Dialtone Handshake

skills CLI
$ npx skills add CALLE-AI/awesome-phone-call-agents --skill dialtone-handshake -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install CALLE-AI/awesome-phone-call-agents dialtone-handshake --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/CALLE-AI/awesome-phone-call-agents.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/dialtone-handshake .claude/skills/dialtone-handshake && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
dialtone-handshake
GitHub stars
107
Token cost
~1k tokens
SKILL.md length
491 words
Files
3 (incl. references)
Skills in repo
101
Repo updated
First seen
Licence
MIT

At a glance

A skill your agent uses when an AI phone call agent (outbound caller or inbound voicebot) needs to recognise that the other end of the call is also an AI, switch to a compressed machine mode, and…

  • Works in 3 steps: If a caller says "dialtone one" followed… → After that, answer in short "field:… → State "Human review" truthfully. Never…
  • An AI phone call agent (outbound caller
  • SKILL.md covers When To Use, When Not To Use, Protocol and Inbound Voicebot Adoption, plus 3 more sections
  • Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Dialtone Handshake is an agent skill from CALLE-AI/awesome-phone-call-agents. Use when an AI phone call agent (outbound caller or inbound voicebot) needs to recognise that the other end of the call is also an AI, switch to a compressed machine mode, and label call results by who actually attested them (human, phone system, or AI agent).

Its SKILL.md is about 1k tokens, which your agent loads only when the skill is triggered. The skill folder holds 3 other files, including reference files (for example `references/examples.md` and `references/safety.md`).

The repository describes itself as: Portable phone-call Agent Skills, apps, examples, adapters, and scheduler recipes for AI agents. The licence is MIT.

When your agent uses it

  • An AI phone call agent (outbound caller
  • Inbound voicebot) needs to recognise that the other end of the call is also an AI
  • Switch to a compressed machine mode
  • Label call results by who actually attested them (human

Example prompts

  • “/dialtone-handshake”

Workflow steps

3 steps, taken from the first numbered list in SKILL.md.

  1. If a caller says "dialtone one" followed by "code" and three digits, reply exactly: "Dialtone one acknowledged, code . Automated agent…
  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.

What it can do on your machine

Read from SKILL.md and the folder at commit 38d4118. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    No scripts in the folder and no shell commands in SKILL.md (its code samples are bash).

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    No URLs in SKILL.md.

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Dialtone Handshake loads about 1k tokens when it runs, and up to ~1.7k if it reads all its reference files. Until then it costs about 70 tokens; SKILL.md has 491 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~70
When it runs · the whole SKILL.md, loaded when a task matches
~1k
With references · SKILL.md plus every file in references/, read only if the agent opens them
~1.7k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from CALLE-AI/awesome-phone-call-agents at commit 38d4118, republished under its MIT licence (© CALLE-AI). 491 words, ~1,011 tokens.

Download SKILL.mdSave it as .claude/skills/dialtone-handshake/SKILL.md (or your agent's skills folder). This skill also uses 2 other files; get the full folder from GitHub.
name
dialtone-handshake
description
Use when an AI phone call agent (outbound caller or inbound voicebot) needs to recognise that the other end of the call is also an AI, switch to a compressed machine mode, and label call results by who actually attested them (human, phone system, or AI agent).

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 answeredModeStyle
Acknowledged, or clearly an automated agentMACHINEfield: value sentences; ask only for outcome, confirmation code, and human review
Phone menuMENUNavigate with keypad tones or short options
Otherwise, or unsureHUMANFull disclosure, natural pace

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

LabelWho confirmedCounts as task completed?
human_attestedA person, with high detector confidenceYes
system_assertedA phone system read back a recordYes
agent_assertedAn AI agent: information, or a commitment with a verifiable artifactYes
refusedAn AI agent confirmed a binding commitment with no artifactNo
unverifiedNothing confirmed, or the counterpart is uncertainNo

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

Show full SKILL.md (146 more words)Show less

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 <same digits>. Automated agent. Human review: <yes or no>."
  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:

bash
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.

© CALLE-AI, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 2 other files (references) in skills/dialtone-handshake of CALLE-AI/awesome-phone-call-agents.

  • SKILL.md
  • references/examples.md
  • references/safety.md

Open the folder on GitHubat commit 38d4118

Compare with similar skills

Dialtone Handshake next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Dialtone Handshake compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Dialtone Handshake this skillCALLE-AI/awesome-phone-call-agents107—~1kAutomated safety check: PassMIT
PhoneBlockRunAI/ClawRouter6.6k—~2.4kAutomated safety check: PassMIT
Adding Inbound WebhooksPostHog/posthog40k—~3.1kAutomated safety check: PassCustom licence
Migrating LLM Gateway CallersPostHog/posthog40k—~1.3kAutomated safety check: PassCustom licence
Phone Harnessmilind-soni/OpenMausBot4.4k—~364Automated safety check: PassApache-2.0
Phone HarnessShawnPana/phone-harness3.2k—~7.7kAutomated safety check: PassMIT

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Questions about Dialtone Handshake

What does Dialtone Handshake do?

A skill your agent uses when an AI phone call agent (outbound caller or inbound voicebot) needs to recognise that the other end of the call is also an AI, switch to a compressed machine mode, and…. Dialtone Handshake is an agent skill from CALLE-AI/awesome-phone-call-agents. Use when an AI phone call agent (outbound caller or inbound voicebot) needs to recognise that the other end of the call is also an AI, switch to a compressed machine mode, and label call results by who actually attested them (human, phone system, or AI agent).

When should I use Dialtone Handshake?

Dialtone Handshake fits situations like: an AI phone call agent (outbound caller; inbound voicebot) needs to recognise that the other end of the call is also an AI; switch to a compressed machine mode; label call results by who actually attested them (human.

How do I install Dialtone Handshake in Claude Code?

Run `npx skills add CALLE-AI/awesome-phone-call-agents --skill dialtone-handshake -a claude-code`. Or copy the skill folder (skills/dialtone-handshake in CALLE-AI/awesome-phone-call-agents) into .claude/skills/dialtone-handshake in your project. Claude Code loads it when a task matches its description.

How do I install Dialtone Handshake in Codex?

Run `npx skills add CALLE-AI/awesome-phone-call-agents --skill dialtone-handshake -a codex`. Or copy the skill folder (skills/dialtone-handshake in CALLE-AI/awesome-phone-call-agents) into .agents/skills/dialtone-handshake in your project. Codex loads it when a task matches its description.

Can I use Dialtone Handshake in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add CALLE-AI/awesome-phone-call-agents --skill dialtone-handshake -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/dialtone-handshake, .gemini/skills/dialtone-handshake, .github/skills/dialtone-handshake and .opencode/skills/dialtone-handshake in your project.

What does Dialtone Handshake need to run?

SKILL.md names no scripts, command-line tools or credentials: Dialtone Handshake is instructions for the agent only.

Does Dialtone Handshake access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Dialtone Handshake safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Dialtone Handshake use?

Dialtone Handshake is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Dialtone Handshake use?

About 1k tokens (SKILL.md is roughly 4k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 725 tokens, read only when the agent opens those files.

What are the alternatives to Dialtone Handshake?

Skills that share tags, products or a category with Dialtone Handshake: Phone (BlockRunAI/ClawRouter, 6.6k stars), Adding Inbound Webhooks (PostHog/posthog, 40k stars), Migrating LLM Gateway Callers (PostHog/posthog, 40k stars) and Phone Harness (milind-soni/OpenMausBot, 4.4k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Dialtone Handshake?

CALLE-AI (a GitHub organization) maintains it in CALLE-AI/awesome-phone-call-agents, which has 107 GitHub stars. The repository holds 101 skills in this directory. The repository was last updated on October 10, 2026.

Source: CALLE-AI/awesome-phone-call-agents on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.