# Retell AI — Pay-as-you-go platform for building, testing and running AI phone, chat and SMS agents.

> Source: The Agents Index — https://theagentsindex.com/retell-ai (structured, researched, re-verified)
> Facts last verified: 2026-09-23

Retell AI is a voice-agent platform for building, testing, deploying and monitoring AI phone, web-call, chat and SMS agents. Agents are built as drag-and-drop conversation flows or single prompts, with telephony, knowledge bases, CRM tools and call analytics included.

| Fact | Value |
| --- | --- |
| Website | https://www.retellai.com |
| Price | from $0.07/minute pay-as-you-go |
| Free trial | Partly |

$10 in free trial credits, granted once per email address; 20 concurrent calls and the first 10 knowledge bases are free on the pay-as-you-go plan, and calls stop when the credit balance hits zero.

## What it does

**Writes tests** · Partly — Produces graded conversation test cases for its own agents, not software tests.

> Run graded test cases to catch regressions before launch.
> — https://docs.retellai.com/general/introduction · Test section, Simulation testing card

**Done-for-you service** · Partly — You run the software yourself in Retell's no-code studio; hands-on implementation by Retell's people is sold only as an Enterprise add-on, not as a managed service.

> Dedicated Implementation Support (add-on)
> — https://www.retellai.com/pricing · Enterprise Plan card, 'Everything from pay as you go, plus' list

## How much it does unattended

**Runs autonomously** · Yes — Agents take and place whole calls without a person on the line, including scheduled outbound campaigns with pacing, retries and voicemail handling; a human can listen in and take over by choice, not by requirement.

> Upload your audience, schedule campaigns, control pacing and retries, handle voicemail, and let AI agents call at scale.
> — https://www.retellai.com/ · 'Built for the Complexity of Real Call Centers' section, Outbound Campaigns at Scale

**Multi-agent** · Yes — One call can be handed between several specialised AI agents mid-conversation, with the destination agent inheriting the full transcript, so work is split across agents rather than one monolith.

> Agent Transfer (also known as Agent Swap) enables you to modularize tasks and re-use specialized agents without relying on traditional phone-based transfers.
> — https://docs.retellai.com/build/conversation-flow/transfer-agent-node · Agent Transfer Node page, opening paragraph

**Agent permissions** · Partly — Prohibited-topic guardrails screen both the agent's replies and user input, and tools are explicitly wired per node, but guardrails only swap in a placeholder message rather than stopping or escalating the call.

> Guardrails do not end the call, transfer the call, or trigger any other action — they only replace the problematic message.
> — https://docs.retellai.com/build/guardrails · How Guardrails Work section

## Which models it runs on

**Claude** · Yes — Claude models are selectable as the agent's conversation model and priced per minute for voice and per message for chat, alongside GPT and Gemini options.

> Claude 5 SonnetRecommended | $0.064/minute
> — https://www.retellai.com/pricing · Detailed Component Pricing table, LLM rows

**GPT** · Yes — Multiple GPT tiers are offered as conversation models, each with its own per-minute rate and an optional faster tier for lower latency.

> GPT 5.4Recommended | $0.080/minute | $0.16/minute
> — https://www.retellai.com/pricing · Detailed Component Pricing table, LLM rows

**Open models** · Partly — Retell's own model menu is limited to hosted GPT, Claude and Gemini, but the custom-LLM path lets you put a self-hosted open-weights model behind the agent over a WebSocket you operate.

> A fine-tuned model, a self-hosted open-weights model, or a provider outside the supported options.
> — https://docs.retellai.com/integrate-llm/overview · When to use it, 'A model Retell doesn't offer'

**Model choice** · Yes — You pick the conversation model per agent from a published, per-minute-priced list, and you can substitute your own model entirely through the custom-LLM WebSocket.

> With a custom LLM, you own response generation.
> — https://docs.retellai.com/integrate-llm/overview · Custom LLM overview, opening paragraph

## Where you use it

**In your editor** · Partly — There is no editor plugin for building calls, but the hosted MCP server lets IDE-based assistants such as Cursor create, publish and inspect Retell agents from inside the editor.

> Retell supports the Model Context Protocol (MCP) so you can build Retell AI voice agents directly from MCP-capable clients (Cursor, Claude Desktop, Claude Code, Codex-style tools, and more).
> — https://docs.retellai.com/get-started/mcp-server · Overview section

**On the command line** · No — The docs enumerate every way to drive Retell: dashboard, REST API, Node/Python SDKs and MCP server. No command-line tool is among them.

> Build entirely from the dashboard with no code, or go fully programmatic with the API, SDKs, and an MCP server.
> — https://docs.retellai.com/general/introduction · Introduction to Retell, 'Developer friendly' section intro

**In a browser** · Yes — Everything is built and operated in a hosted browser dashboard, and agents themselves can also be embedded on your own site as a web call or chat widget.

> Embed the Retell website widget on your site with a single script tag — supports chat, voice, and callback modes powered by your chat and voice agents.
> — https://docs.retellai.com/deploy/chat-widget · Retell Website Widget page, description

## Whose machine it runs on

**Self-hosted** · No — The platform runs on Retell's own infrastructure: pay-as-you-go uses shared servers and the most isolation offered is a dedicated Retell server sold as an Enterprise add-on, with no customer-infrastructure deployment documented.

> Server | Shared | Dedicated stable server (add-on)
> — https://www.retellai.com/pricing · Compare Plans table, Infrastructure > Server row

_Not established: Open source_

## What it costs to run

**How it meters** · Yes — Billing is consumption-based: voice agents bill per call minute split across voice infra, model and telephony, chat agents bill per AI message, with named add-ons metered per minute or per dial.

> $0.07-$0.31 / min for AI Voice Agents
> — https://www.retellai.com/pricing · Pay as you go plan card, price bullets

**Free tier** · Partly — You can sign up and run real calls without talking to sales, but the free allowance is a one-off $10 trial credit per email address rather than a standing free plan.

> New accounts start with $10 in free trial credits so you can test Retell before adding a payment method. The trial credit is granted once per email address.
> — https://docs.retellai.com/accounts/billing · Credit-based billing tab, How credit-based billing works

**API access** · Yes — A documented REST API with Node.js and Python SDKs covers agents, calls, phone numbers and chats, and it is listed as included on the entry pay-as-you-go plan.

> Webhooks and API Access
> — https://www.retellai.com/pricing · Pay as you go plan card, Key Features Include list

**MCP server** · Yes — Retell runs a hosted MCP endpoint authenticated with an API key, exposing agent, call, knowledge-base and QA tools so another assistant can drive the account.

> Retell MCP server URL: https://mcp.retellai.com
> — https://docs.retellai.com/get-started/mcp-server · Prerequisites section

**Bring your own key** · Partly — You can bring your own model server and your own telephony carrier over SIP, but there is no documented way to supply your own OpenAI or Anthropic keys for Retell's built-in models.

> Run your own LLM behind a Retell voice agent. Retell handles telephony, transcription, and turn-taking while your WebSocket server generates each reply.
> — https://docs.retellai.com/integrate-llm/overview · Custom LLM overview, page summary

## Buying it for a team

**A company can buy it** · Yes — Work is organised in workspaces with invited members and per-workspace billing, and an Enterprise plan adds negotiated contracts for organisations buying centrally.

> Billing is scoped per workspace, not per account. Every workspace, including new ones you create later, has its own payment method, credit balance, invoices, and usage totals.
> — https://docs.retellai.com/accounts/billing · Which billing version am I on? note

**Seat model** · No — Nothing is charged per user: the published rate card meters minutes, messages and monthly items like phone numbers and concurrency, so team size does not change the bill.

> True pay as you go. Only pay for the minutes you use.
> — https://www.retellai.com/pricing · Pricing page hero heading

**Pooled budget** · Yes — A workspace holds one prepaid credit balance that every agent and member draws down in real time, and it blocks all new calls when it empties.

> When your credit balance reaches zero, new calls are blocked until you buy credits or auto recharge tops up your balance.
> — https://docs.retellai.com/accounts/billing · Credit-based billing tab, warning callout

**Admin controls** · Partly — Admin, Developer and Member roles constrain who can edit agents, see raw transcripts or change limits, but the pricing comparison marks role-based access control as an Enterprise capability rather than a pay-as-you-go one.

> To keep your workspace safe, we have an RBAC (Role-Based Access Control) system.
> — https://docs.retellai.com/accounts/access-control · Access Control page, opening line

**Audit log** · Partly — Agent configuration changes are recorded as immutable published versions with browsable history and side-by-side comparison; no workspace-level log of administrative actions such as role changes or key rotation is documented.

> Version control & history: you can create multiple draft versions from any past version, track your version history, and publish any draft when it's ready.
> — https://docs.retellai.com/agent/version · Set up versioning and tags for agents, 'two main purposes' list, item 2

**Single sign-on** · Partly — Ordinary accounts can sign in with Google, while configurable enterprise single sign-on is listed only under the Enterprise plan and the protocol supported is not named.

> Custom SSO
> — https://www.retellai.com/pricing · Enterprise Plan card, 'Everything from pay as you go, plus' list

## What happens to your code

**Opt out of training** · Partly — Per-agent data storage settings let you keep transcripts and recordings out of Retell entirely, but the privacy policy states collected information is used to train its models and publishes no separate training opt-out.

> to train the artificial intelligence models that support our Services or that support our business and administrative functions;
> — https://www.retellai.com/legal/privacy-policy · How we use the personal information that we collect, bullet list

**Data residency** · Partly — Processing is in the United States on AWS with SCCs for EU transfers; the vendor states plainly that it runs no services inside the European Union, so EU-resident hosting is not on offer.

> However, please note that we do not currently operate services within the European Union.
> — https://docs.retellai.com/general/compliance · Is Retell GDPR compliant? section

**Getting out** · Yes — Filtered call and chat history exports to CSV including transcripts, and list/get APIs cover the same data; purchased credits never expire but are non-refundable once bought.

> Open Actions, select Export, and choose the columns to include. Export-only fields include transcript data and PII-scrubbed transcripts.
> — https://docs.retellai.com/features/session-history · Export sessions to CSV, step 1

**Certifications** · Yes — HIPAA, GDPR and SOC 2 Type 1 and Type 2 are claimed, with BAA and DPA self-signing at no extra fee and reports available through a trust centre.

> we are proud to be HIPAA compliant, GDPR compliant, SOC 2 Type 1 & Type 2 certified
> — https://docs.retellai.com/general/compliance · Security and compliance, opening paragraph

## Provenance

Every fact above comes from the vendor. Nothing here is independently corroborated yet.

## Coverage elsewhere

Pages about this product that the vendor does not control. The label states how independent each one is.

| Source | Kind | Read |
| --- | --- | --- |
| sacra.com | Independent source | 2026-08-23 |
| g2.com | Review platform | 2026-08-23 |
| synthflow.ai | A competitor's comparison | 2026-08-23 |
| autocalls.ai | Independent source | 2026-08-23 |

## What changed

- 2026-09-23 — Capabilities · Commercial terms · Free tier
- 2026-09-02 — Capabilities · Commercial terms · Free tier
- 2026-08-31 — Capabilities · Commercial terms · Free tier · Price
- 2026-08-23 — Alternatives · Crunchbase link · LinkedIn link · One-liner · Summary
- 2026-08-19 — Summary

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