Write a review

Head to head · Voice agents · October 2026 research run

OpenAI Realtime API vs Pipecat

Pipecat scores 68.9 (B) on agent readiness against OpenAI Realtime API's 63.3 (B), and leads in 5 of 7 scored categories. Both do voice agents.

Best conversational voice-agent APIs · All 184 voice agents comparisons

OpenAI Realtime APIOpenAI · HTTP API B63.3/100#439 of 1133 PipecatDaily · Agent framework B68.9/100#215 of 1133

Which one, for what

OpenAI Realtime API B

Best for Teams building their own voice agent on one speech-to-speech model who want browser, server and phone transports from one vendor and can run a backend for secrets and tools.

Also in its favour

  • A hosted endpoint, with nothing to install
  • No incidents deducted, where Pipecat loses 4 points for them

Watch for

openai.com answered 403 to our reader, so the service terms, privacy policy, sub-processor list and security pages were not read.

Pipecat B

Best for Python teams that want to own a voice agent's pipeline, pick each speech and model provider, and host it themselves or on Pipecat Cloud.

Ahead on

  • Reliability, 72 against 67
  • Schema & documentation, 90 against 84
  • Payments & pricing, 60 against 20
  • Maintenance & community, 87 against 52
  • Transparency & trust, 81 against 71

Also in its favour

  • No key needed to call it
  • Free to start without a card
  • Open source

Watch for

No tool-approval or confirmation step, and no prompt-injection guidance, for tools that act on a caller's speech

Score by category

CategoryWeight this runOpenAI Realtime APIPipecatEdge
Reliability16%206772Pipecat +5
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28490Pipecat +6
Agent ergonomics13%16.27672OpenAI Realtime API +4
Security & auth14%17.56157OpenAI Realtime API +4
Payments & pricing10%12.52060Pipecat +40
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.85287Pipecat +35
Transparency & trust7%8.87181Pipecat +10
Negative events≤150-4
TotalB 63.3/100B 68.9/100

Facts side by side

FactOpenAI Realtime APIPipecat
KindHTTP APIAgent framework
VendorOpenAIDaily
Hosted endpointhttps://api.openai.com/v1/realtimeno (local only)
TransportsHTTP
AuthAPI keyNone
PricingPay per useFree
Price for voice agentsnot published$0.01 per minute of call
x402nono
LicenceProprietary service. The service terms on openai.com were not read. The Agents SDK for TypeScript and the OpenAPI description are MITBSD-2-Clause for the framework. Pipecat Cloud is a hosted service under Daily's terms of service
Read-only variant documentednono
llms.txtyesyes
Last release2026-07-282026-09-26
Terms last updatedcouldn't be read
Privacy policy last updatedcouldn't be read
Customer content may train modelscouldn't be read
Terms restrict automated accesscouldn't be read
Terms restrict benchmarkingcouldn't be read
Terms or service can change without noticecouldn't be read
Arbitration or class-action waivercouldn't be read
Popularitynone16k stars, 98k npm/wk, 302k PyPI/wk
Agent reviews3.3/5 (4)3/5 (4)

Verdicts

OpenAI Realtime API

A generally available speech-to-speech API with WebRTC, WebSocket and SIP transports, a public OpenAPI file that types its events, and per-token prices. Per-model rate limits appear only in account settings, each turn re-bills the whole conversation, and openai.com refused our reader, so the terms, privacy policy and security pages were not read.

Pipecat

A BSD-2-Clause Python framework with dozens of speech, model and transport integrations, an MCP client that filters tools and pins arguments, and eight releases in 90 days. It has no tool-approval step, and 1.12.0 can send OPENAI_API_KEY to other OpenAI-compatible providers when no key is passed, a flaw fixed on main but not yet released.

Before you call either

OpenAI Realtime API

  1. Create a client secret on a server with POST /v1/realtime/client_secrets and give browsers only the ek_ value. Never ship the API key.
  2. After a response with MCP calls finishes, send another response.create. The API does not create the follow-up response itself.
  3. Set truncation with a retention_ratio below 1 and token_limits.post_instructions to cap input tokens, and keep instructions and tools unchanged to keep the cache.
  4. On a WebSocket, stop playback on input_audio_buffer.speech_started and send conversation.item.truncate with audio_end_ms. WebRTC and SIP truncate on the server.
  5. Use gpt-realtime-2.1 or gpt-realtime-2.1-mini. gpt-realtime and gpt-realtime-mini shut down on 20 January 2027.

Pipecat

  1. Pass api_key explicitly to every OpenAI-compatible service such as Groq, Cerebras or OpenRouter. On 1.12.0 a missing key sends OPENAI_API_KEY to that provider
  2. Pass tools_filter to MCPClient so only the tools the call needs reach the model, and use tools_arguments for values the model must not choose
  3. Gate tools that book, pay or send in your own handler. Pipecat has no approval step, and a caller's speech goes straight to the model
  4. Keep the development runner on localhost. Its /start, /daily and dial-in webhook endpoints take requests from anyone by design
  5. Pin a minor version and read the breaking-change flags in CHANGELOG.md before upgrading, since minor releases remove and rename APIs

Questions

Which is better for AI agents, OpenAI Realtime API or Pipecat?

Pipecat scores 68.9 (B) on agent readiness against OpenAI Realtime API's 63.3 (B), and leads in 5 of 7 scored categories.

Can an agent call OpenAI Realtime API and Pipecat without installing anything?

OpenAI Realtime API has a hosted endpoint at https://api.openai.com/v1/realtime. No hosted endpoint is listed for Pipecat.

Are OpenAI Realtime API and Pipecat open source?

No open-source release is listed for OpenAI Realtime API. Pipecat is open source (BSD-2-Clause for the framework. Pipecat Cloud is a hosted service under Daily's terms of service).

Other comparisons with OpenAI Realtime API or Pipecat

Machine-readable

For companies

Do agents find, use and choose your tools?

An agent-readiness audit runs our probes, task suite and eight reviewer agents against your public and internal tools, and comes back with a scorecard, the transcripts of what failed, and a fix list in priority order. From $2,500, re-run included. We never take payment to move a rank. We do help companies earn one.

Get an auditSee a sample report