Tone

C tier on AI Voice AgentsScore 6.9 · #5 of 31

Android app: Not listed
Free plan: Yes
Paid plans from: $0.09/mo
Runs on: api, self-hosted, Web

Summary

Tone is an open-source platform for building, deploying, and self-hosting voice agents. Agents can handle inbound or outbound calls, web widgets, and chat, and can combine prompts, tools, workflows, models, voices, and speech-to-text providers. Its knowledge base accepts PDFs, scraped documents, Notion, and Confluence content, with retrieval, citations, and custom vocabulary. A visual workflow builder offers branching, loops, human handoff, TypeScript hooks, and triggers from Zapier, REST API, or HighLevel. Developers can run simulated calls, replay production calls, and monitor signals such as latency, sentiment, and interruptions. Tone offers a TypeScript SDK, CLI, hosted API, and self-hosting with Docker Compose or a Kubernetes Helm chart. It is available through the web, API, or self-hosted deployment. The Self-host plan is free; Cloud is billed at $0.09 per minute and includes $10 free credit with no card required. Tone is MIT licensed and lists 29 supported languages.

Who it is for

Tone suits developers and teams building voice agents across phone, web-widget, or chat channels. Its self-hosting and workflow tools may also suit organizations that want control over deployment and agent logic.

What is good

Free self-host plan with unlimited agents, calls, and workflows
Agents support inbound and outbound calls
Workflow builder includes branching, loops, and human handoff
Knowledge base supports citations and custom vocabulary
TypeScript SDK, CLI, and hosted API

What to know first

Cloud is billed at $0.09 per minute
Enterprise pricing is custom and not listed
Self-host support is through community Discord

Verdict

Tone combines voice-agent authoring, workflow design, testing, and monitoring in an open-source platform. The free self-host option and per-minute Cloud plan offer different deployment paths.

Tone plans and pricing

All plans

Self-host Free $0 Unlimited agents, calls, workflows · Bring your own LLM, voice, telephony · Docker Compose & Helm chart · Community Discord support · All integrations included trytone.ai · 30 Sept 2026

Cloud $0.09/mo $0.09 per minute $10 free credit, no card required · Auto-scaling worker fleet · 99.99% uptime SLA · SOC 2 Type II · HIPAA-ready · Email & chat support · Pay-as-you-go, cancel anytime trytone.ai · 30 Sept 2026

Enterprise Not published Custom Single-tenant or on-prem · BAA, DPA, custom contracts · Dedicated support and Slack channel · Custom integrations and roadmap · Audit logs, SSO/SAML, RBAC trytone.ai · 30 Sept 2026

Compared on AI voice agents

Free plan: Yestrytone.ai
Inbound calls: Yestrytone.ai
Outbound calls: Yestrytone.ai
Human handoff: Yestrytone.ai
Supported languages: 29 languagestrytone.ai
Custom phone numbers: Yestrytone.ai

Facts

What it does: Tone is an open-source voice AI platform for building, deploying, and self-hosting voice agents.trytone.ai · 30 Sept 2026
Agent channels: Agents can run inbound, outbound, web-widget, or chat experiences.trytone.ai · 30 Sept 2026
Agent composition: Agents combine prompts, tools, workflows, configurable models, voices, and speech-to-text providers.trytone.ai · 30 Sept 2026
Knowledge base: Tone ingests PDFs, scraped documents, Notion, and Confluence content and provides chunking, embeddings, retrieval, re-ranking, citations, and custom vocabulary.trytone.ai · 30 Sept 2026
Workflow builder: The visual workflow builder supports branching, loops, human handoff, TypeScript hooks, and triggers from Zapier, REST API, or HighLevel.trytone.ai · 30 Sept 2026
Testing: The test center runs simulated calls with personas, accents, and edge cases, supports parallel regression runs, and replays production calls.trytone.ai · 30 Sept 2026
Observability: Observability includes interruption rate, latency, sentiment, gibberish detection, stereo recordings, waveform inspection, custom dashboards, and real-time alerts.trytone.ai · 30 Sept 2026
Self-hosting: Tone can be started with Docker Compose and includes a Kubernetes Helm chart, with Postgres, Redis, and ClickHouse in the example stack.trytone.ai · 30 Sept 2026
Open-source license: Tone is MIT licensed and its agent runtime, call routing, and evaluation harness are published on GitHub.trytone.ai · 30 Sept 2026
Security posture: The site states SOC 2 Type II, HIPAA-ready, and GDPR compliance, and the changelog says edge PII redaction and HMAC-SHA256 webhook signing were added.trytone.ai · 30 Sept 2026
Support: Self-host customers receive community Discord support, Cloud customers receive email and chat support, and Enterprise customers receive dedicated support with a Slack channel.trytone.ai · 30 Sept 2026
Performance: The product page states a 218 ms voice-loop p50, 120 ms time-to-first-byte, 10k+ concurrent calls per region, 29 supported languages, and a 99.99% Cloud uptime SLA.trytone.ai · 30 Sept 2026
Developer access: Tone provides a TypeScript-first SDK, CLI, local Docker development loop, composable runtime, and hosted API access.trytone.ai · 30 Sept 2026