#55 in Frameworks & LibrariesUpdated 2026-08

Fonoster

by Fonoster · Open-source programmable voice and messaging platform

37 — BenchRank score out of 100

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Pricing page

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Overview

Fonoster is a programmable voice and messaging platform positioned as an open-source alternative to Twilio. Developers build voice applications with verbs such as Play, Say and Gather using a Node.js/browser SDK and a CLI, and place or receive calls via its API. It also offers text-to-speech, speech recognition, S3-backed sound storage and OAuth2/JWT authentication.

Best for: Developers building voice or messaging apps who want an open-source alternative to Twilio
Pricing: No prices are shown: a free rate-limited plan, a Pro plan with 520 mins/mo free then pay-as-you-go, and a contact-sales Advanced plan; the open-source edition is free to self-host.
Runs on: WebSelf-hostedCLI

Strengths and trade-offs

Strengths

Node.js SDK and CLI, installable from NPM or CDN
Community Edition can be self-hosted for free
Voice verbs (Play, Say, Gather) plus TTS and speech recognition
OAuth2/JWT project-level auth and S3 sound storage

Trade-offs

No prices published for the Pro plan; Advanced is contact-sales only
Free plan capped at 30 mins/mo, 1 workspace, 1 domain, 1GB storage
Free plan support is community-only via issue tracker and discussions
Single Sign-On is marked "Coming Soon" on the Advanced plan

Pricing

Published plans from Fonoster’s own pricing page, in USD. Usage charges and add-ons may apply on top.

Fonoster pricing tiers, monthly rates in USD
Plan	Monthly	Includes
FREE	—	1 workspace, 1 domain 30 mins/mo, 1GB storage 1-week log retention Community support
PRO	—	Unlimited workspaces and domains 520 mins/mo free, then pay-as-you-go 10GB storage 30-day log retention, email support
ADVANCED	Contact sales	Technical support with SLAs Volume commitment pricing Technical onboarding and customer success manager Single Sign-On (coming soon)

How this score is made up

Each dimension is scored out of 100 and combined into the headline score using fixed weights.

MCP support: 0 out of 100
API quality: 30 out of 100
Documentation: 80 out of 100
Agent friendliness: 41 out of 100
Changelog: 55 out of 100
Marketing site structure: 55 out of 100
Operational trust: 0 out of 100

Measured, but not part of the score

Useful to know, but not a mark for or against the product — so these do not affect the ranking.

Openness: 85 out of 100
Maintenance: 90 out of 100

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