aid: retell url: https://raw.githubusercontent.com/api-evangelist/retell/refs/heads/main/apis.yml name: Retell AI kind: company description: Retell AI is a platform to build, test, and deploy AI voice agents for phone calls. Its conversational voice API orchestrates LLM responses, telephony, speech, and call analysis so developers can place and receive natural-sounding automated calls, with a real-time WebSocket for bringing your own custom LLM and streaming call audio. image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg tags: - AI - Voice - Voice Agents - Conversational AI - Telephony created: '2026-07-01' modified: '2026-07-01' specificationVersion: '0.19' apis: - aid: retell:agents name: Agents tags: - Agents - Voice Agents - Configuration image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://docs.retellai.com/api-references/create-agent baseURL: https://api.retellai.com properties: - url: https://docs.retellai.com/build/create-your-first-agent type: Documentation - url: https://docs.retellai.com/api-references/create-agent type: APIReference - url: openapi/retell-openapi.yml type: OpenAPI description: Create, retrieve, list, update, and delete voice agents that pair a response engine (Retell LLM, custom LLM, or conversation flow) with a voice and call-behavior settings. - aid: retell:retell-llm name: Retell LLM tags: - LLM - Orchestration - Prompt image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://docs.retellai.com/api-references/create-retell-llm baseURL: https://api.retellai.com properties: - url: https://docs.retellai.com/build/llms/overview type: Documentation - url: https://docs.retellai.com/api-references/create-retell-llm type: APIReference - url: openapi/retell-openapi.yml type: OpenAPI description: Manage the Retell-hosted LLM response engine - general prompt, model, temperature, tools, multi-state flows, begin message, and knowledge base references that drive agent conversations. - aid: retell:conversation-flow name: Conversation Flow tags: - Conversation Flow - Node Graph - Deterministic image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://docs.retellai.com/api-references/create-conversation-flow baseURL: https://api.retellai.com properties: - url: https://docs.retellai.com/build/conversation-flow/overview type: Documentation - url: https://docs.retellai.com/api-references/create-conversation-flow type: APIReference - url: openapi/retell-openapi.yml type: OpenAPI description: Manage node/edge conversation flows for visually structured, deterministic agent conversations as an alternative response engine to the Retell LLM. - aid: retell:phone-calls name: Phone Calls tags: - Phone Call - Outbound - Telephony image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://docs.retellai.com/api-references/create-phone-call baseURL: https://api.retellai.com properties: - url: https://docs.retellai.com/make-calls/outbound-call type: Documentation - url: https://docs.retellai.com/api-references/create-phone-call type: APIReference - url: openapi/retell-openapi.yml type: OpenAPI description: Place outbound PSTN calls (POST /v2/create-phone-call) and retrieve or list completed calls with transcript, recording URL, call analysis, and cost breakdown. - aid: retell:web-calls name: Web Calls tags: - Web Call - WebRTC - Browser image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://docs.retellai.com/api-references/create-web-call baseURL: https://api.retellai.com properties: - url: https://docs.retellai.com/make-calls/web-call type: Documentation - url: https://docs.retellai.com/api-references/create-web-call type: APIReference - url: openapi/retell-openapi.yml type: OpenAPI - url: asyncapi/retell-asyncapi.yml type: AsyncAPI description: Register browser-based (WebRTC) calls (POST /v2/create-web-call) and receive an access_token to hand to the Retell Web Client SDK for real-time in-browser voice conversations. - aid: retell:phone-numbers name: Phone Numbers tags: - Phone Numbers - Provisioning - SIP image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://docs.retellai.com/api-references/create-phone-number baseURL: https://api.retellai.com properties: - url: https://docs.retellai.com/deploy/phone-number type: Documentation - url: https://docs.retellai.com/api-references/create-phone-number type: APIReference - url: openapi/retell-openapi.yml type: OpenAPI description: Buy Retell-managed numbers or import your own via SIP trunk, and bind inbound and outbound agents to each number for automated call handling. - aid: retell:voices name: Voices tags: - Voices - TTS - Speech image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://docs.retellai.com/api-references/list-voices baseURL: https://api.retellai.com properties: - url: https://docs.retellai.com/build/voices type: Documentation - url: https://docs.retellai.com/api-references/list-voices type: APIReference - url: openapi/retell-openapi.yml type: OpenAPI description: List and retrieve the catalog of available voices across TTS providers (ElevenLabs, OpenAI, PlayHT, Cartesia, Deepgram) with accent, gender, age, and preview audio. - aid: retell:knowledge-bases name: Knowledge Bases tags: - Knowledge Base - RAG - Retrieval image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://docs.retellai.com/api-references/create-knowledge-base baseURL: https://api.retellai.com properties: - url: https://docs.retellai.com/build/knowledge-base type: Documentation - url: https://docs.retellai.com/api-references/create-knowledge-base type: APIReference - url: openapi/retell-openapi.yml type: OpenAPI description: Create knowledge bases from texts, files, and URLs, manage their sources, and reference them from a Retell LLM or conversation flow for retrieval-augmented answers during calls. - aid: retell:batch-call name: Batch Call tags: - Batch Call - Campaigns - Outbound image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://docs.retellai.com/api-references/create-batch-call baseURL: https://api.retellai.com properties: - url: https://docs.retellai.com/make-calls/batch-call type: Documentation - url: https://docs.retellai.com/api-references/create-batch-call type: APIReference - url: openapi/retell-openapi.yml type: OpenAPI description: Queue outbound calling campaigns to many recipients from a single from_number with per-task dynamic variables, subject to available call concurrency. - aid: retell:concurrency name: Concurrency tags: - Concurrency - Rate Limiting - Capacity image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg humanURL: https://docs.retellai.com/api-references/get-concurrency baseURL: https://api.retellai.com properties: - url: https://docs.retellai.com/api-references/get-concurrency type: APIReference - url: openapi/retell-openapi.yml type: OpenAPI - url: rate-limits/retell-rate-limits.yml type: RateLimits description: Read the organization's current and maximum simultaneous-call concurrency (GET /get-concurrency) - the primary capacity and throttling lever for outbound and batch calling. common: - type: DomainSecurity url: security/retell-domain-security.yml - type: Authentication url: authentication/retell-authentication.yml - type: GitHubOrganization url: https://github.com/RetellAI - type: LinkedIn url: https://www.linkedin.com/company/retell-ai - type: Website url: https://www.retellai.com/ - type: Documentation url: https://docs.retellai.com - type: Plans url: plans/retell-plans-pricing.yml - type: RateLimits url: rate-limits/retell-rate-limits.yml - type: FinOps url: finops/retell-finops.yml - type: Blog url: https://www.retellai.com/blog maintainers: - FN: Kin Lane email: kin@apievangelist.com