Built by Metorial, the integration platform for agentic AI.
Delete a phone number from your Retell AI account. This action is irreversible.
Retrieve detailed configuration of a specific voice agent by its ID, including voice settings, response engine, language, webhook configuration, and more. Optionally specify a version to retrieve a specific version of the agent.
Create a batch outbound calling campaign to automate large-scale outreach. Specify a source number and a list of tasks (destination numbers) with optional per-call customizations. Campaigns can be scheduled or started immediately.
Retrieve detailed information about a specific call, including transcript, recording URL, call analysis, cost breakdown, latency metrics, and disconnection reason.
Initiate an outbound phone call. Specify the source number (must be owned/imported in Retell) and destination number. Optionally override the agent, inject dynamic variables, or attach metadata.
Delete a voice agent and all of its versions. This action is irreversible.
Initiate a browser-based voice call via WebRTC. Returns an access token that can be used by the frontend to join the call room. No telephony infrastructure required.
Check your current call concurrency usage, limits, and purchasing capacity. Useful for monitoring capacity before launching batch campaigns.
List and filter calls in your Retell AI account. Filter by agent, status, type, direction, sentiment, date range, and more. Supports pagination and sorting.
List all phone numbers in your Retell AI account, including their assigned agents, type, and configuration.
List all knowledge bases in your Retell AI account, including their status, sources, and configuration.
Purchase a new phone number from Retell. Specify an area code and optionally assign inbound/outbound agents.
Retrieve detailed information about a specific knowledge base, including its sources and processing status.
Update the configuration of an existing voice agent. You can modify voice settings, language, webhooks, behavioral parameters, response engine, and more. Only provided fields will be updated.
Create a new voice agent with a specified voice and response engine configuration. Agents can be configured with various voice settings, language, webhooks, and behavioral parameters.
Browse available voices for Retell AI agents. Returns all voices with their provider, gender, accent, and preview audio. Use to find the right voice ID when creating or updating agents.
Retrieve details of a specific phone number, including assigned agents, webhooks, and country restrictions.
Delete a knowledge base from your Retell AI account. This action is irreversible.
Delete a call record from your Retell AI account. This action is irreversible.
List voice agents in your Retell AI account. Returns unique voice agent IDs, names, and environment tags. Use get_agent for version configuration. Supports pagination for large collections.
Update configuration of an existing phone number, including assigned agents, webhooks, and country restrictions.
Delete an unused response engine. Delete or detach agents that reference it first; Retell rejects deletion while it is in use.
Update the latest draft or an explicitly selected response-engine version. Only supplied settings are changed.
Discover prompt-based response engines and their IDs for create_agent or update_agent. Supports cursor pagination.
Create a prompt-based Retell response engine. Pass its llmId to create_agent with responseEngine type retell-llm.
Create a knowledge base from text and public URLs for an agent response engine. Indexing is asynchronous; use get_knowledge_base to check status.
Read a response engine and its prompt, model, and knowledge-base configuration.
Prepare a downloadable WAV recording for a completed call. Choose the standard, multichannel, or PII-scrubbed recording when available.
Publish an existing draft version in place so it can serve production calls. Publishing does not create another draft version.