List all Retell AI voice agents in your account. Returns agent IDs, names, voice settings, and configuration.

Get detailed information about a specific Retell AI agent by its ID.

Create a new Retell AI voice agent. Requires a voice_id and one response engine: llm_id (Retell LLM), llm_websocket_url (Custom LLM), or conversation_flow_id (Conversation Flow).

Update an existing Retell AI agent's configuration, including switching to a different response engine type (Retell LLM, Custom LLM, or Conversation Flow).

Permanently delete a Retell AI agent by its ID.

Get all published versions of a Retell AI voice agent.

Publish the latest draft version of a voice agent, creating a new immutable version and starting a fresh draft.

List calls in your Retell AI account. Supports filtering by agent ID, status, and date range. Supports pagination via pagination_key.

Get full details of a specific call including transcript, recording URL, latency, and cost.

Initiate an outbound phone call via a Retell AI agent. Requires a purchased from_number and a destination to_number.

Create a browser-based web call with a Retell AI agent. Returns an access_token for the Retell Web SDK.

Delete a call record from your Retell AI account.

Update metadata or data storage settings for an existing call.

Register a phone call for custom telephony (bring-your-own telephony). Returns call_id and access_token for the audio websocket.

List all phone numbers in your Retell AI account.

Get details about a specific phone number including its associated agent.

Purchase a new US phone number and optionally bind it to an agent.

Update the agent binding or settings for an existing phone number.

Release (delete) a phone number from your Retell AI account.

Import a phone number from your own custom telephony (SIP trunk) and optionally bind agents to it.

List all Retell LLM configurations in your account.

Get details of a specific Retell LLM configuration.

Create a new Retell LLM configuration to attach to agents. Define system prompt, model, begin message, and tools.

Update an existing Retell LLM configuration's prompt, model, or tools.

Delete a Retell LLM configuration by its ID.

List all knowledge bases in your Retell AI account.

Get details about a specific knowledge base.

Create a new knowledge base for RAG. Provide plain-text sources, URLs to crawl, or both.

Delete a knowledge base from your Retell AI account.

Add new text or URL sources to an existing knowledge base.

Remove a specific source from an existing knowledge base by its source ID.

List all available voices for Retell AI agents, including provider, gender, accent, and preview audio URLs.

List all Conversation Flows in your Retell AI account. Conversation Flows are node-based agent scripts with fine-grained control over dialogue, branching, and function execution.

Get full details of a specific Conversation Flow including its nodes, edges, and tools.

Create a new Conversation Flow. A Conversation Flow is a node-graph that controls agent dialogue with conversation nodes, function nodes, branch nodes, and end nodes connected by edges.

Update an existing Conversation Flow's nodes, edges, model, prompt, or tools.

Permanently delete a Conversation Flow and all its versions.

List all shared Conversation Flow Components in your account. Components are reusable sub-flows that can be embedded in multiple Conversation Flows, saving development time and ensuring consistency.

Get full details of a specific shared Conversation Flow Component.

Create a new shared Conversation Flow Component. Components are reusable sub-flows that can be embedded across multiple Conversation Flows.

Update an existing shared Conversation Flow Component's name, nodes, or tools.

Delete a shared Conversation Flow Component. When deleted, local copies are automatically created in all Conversation Flows that use it.

List all chat (text/messaging) agents in your Retell AI account.

Get details of a specific chat agent by its ID.

Create a new chat (text/messaging) agent. Requires a response_engine (llm_id, llm_websocket_url, or conversation_flow_id).

Update an existing chat agent's configuration.

Permanently delete a chat agent by its ID.

Get all published versions of a chat agent.

Publish the latest draft of a chat agent, creating a new immutable version.

List all chat sessions in your Retell AI account.

Get details and transcript of a specific chat session.

Start a new chat session with a chat agent.

Update metadata or data storage settings for an ongoing chat session.

Send a user message to an ongoing chat session and get the agent's response.

Start an outbound SMS chat conversation using a phone number with SMS capability.

End an ongoing chat session.

Schedule a batch of outbound phone calls. Each task specifies a destination number and optional per-call agent overrides and dynamic variables.

Run a batch of automated test cases against a Retell LLM or Conversation Flow response engine.

Get the current live call concurrency and concurrency limits for your Retell organization.

Get the list of MCP tools available from a specific MCP server configured on a Retell agent.