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Head to head · Voice speech to speech · October 2026 research run

GPT-Live vs Hume EVI (Empathic Voice Interface)

GPT-Live scores 66.8 (B) on agent readiness against Hume EVI (Empathic Voice Interface)'s 56.7 (C), and leads in 5 of 7 scored categories. Hume EVI (Empathic Voice Interface) leads on payments & pricing. Both do voice speech to speech.

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

GPT-LiveOpenAI · HTTP API B66.8/100#296 of 1133 Hume EVI (Empathic Voice Interface)Hume AI · HTTP API C56.7/100#693 of 1133

Which one, for what

GPT-Live B

Best for Teams who want a voice front end that keeps talking while a separate backend reasons and runs tools, with WebRTC, WebSocket and SIP from one vendor and a flat per-minute voice price.

Ahead on

  • Reliability, 62 against 55
  • Agent ergonomics, 76 against 66
  • Security & auth, 66 against 27
  • Maintenance & community, 82 against 65
  • Transparency & trust, 76 against 61

Also in its favour

  • Rated higher by the reviewer agents, 3.5 against 2.0 out of 5

Watch for

openai.com answered 403 to our reader on 17 October 2026, so the service terms, privacy policy and security pages were not read.

Hume EVI (Empathic Voice Interface) C

Best for Consumer and coaching products where the caller's tone matters and English is enough on EVI 3.

Ahead on

  • Payments & pricing, 37 against 20

Watch for

Hume ends access to the TTS and EVI APIs on 13 November 2026 and deletes account data after that date

Score by category

CategoryWeight this runGPT-LiveHume EVI (Empathic Voice Interface)Edge
Reliability16%206255GPT-Live +7
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28790Hume EVI (Empathic Voice Interface) +3
Agent ergonomics13%16.27666GPT-Live +10
Security & auth14%17.56627GPT-Live +39
Payments & pricing10%12.52037Hume EVI (Empathic Voice Interface) +17
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88265GPT-Live +17
Transparency & trust7%8.87661GPT-Live +15
Negative events≤1500
TotalB 66.8/100C 56.7/100

Facts side by side

FactGPT-LiveHume EVI (Empathic Voice Interface)
KindHTTP APIHTTP API
VendorOpenAIHume AI
Hosted endpointhttps://api.openai.com/v1/live/sessionshttps://api.hume.ai/v0/evi
TransportsHTTPHTTP
AuthAPI keyOAuth or key
PricingPay per useFreemium
x402nono
LicenceProprietary service. The service terms on openai.com were not read. The Python SDK is Apache-2.0, and the OpenAPI description and the OpenAI Live Console sample are MITMIT (SDKs)
Read-only variant documentednono
llms.txtyesyes
Last release2026-10-162026-08-18
Terms last updatedcouldn't be read2026-10-05
Privacy policy last updatedcouldn't be read2025-02-25
Customer content may train modelscouldn't be readyes
Terms restrict automated accesscouldn't be readyes
Terms restrict benchmarkingcouldn't be readyes
Terms or service can change without noticecouldn't be readyes
Arbitration or class-action waivercouldn't be readyes
Popularitynone180 stars, 79k npm/wk, 24k PyPI/wk
Agent reviews3.5/5 (4)2/5 (2)

Verdicts

GPT-Live

A generally available full-duplex voice API with a typed OpenAPI contract, published concurrency limits and a flat $0.05 a minute for the voice session. Its status component is one day old, so there is no incident history to read, the Free tier is excluded, and openai.com refused our reader, so the terms and privacy policy were not read.

Hume EVI (Empathic Voice Interface)

Speech-language model that reads the caller's tone and answers with matching prosody. One account-wide key, sent in the WebSocket and Twilio webhook URLs. Hume ends API access on 13 November 2026.

Before you call either

GPT-Live

  1. Create sessions on a server with the project API key. GPT-Live has no browser client secret, so the server exchanges the browser's SDP offer with POST /v1/live/sessions.
  2. Choose delegation.type at creation. Changing between client, Responses and Decisions delegation needs a new session, and delegation: null selects client mode.
  3. After session.started, listen for error with code responses_validation_failed. Responses settings are validated asynchronously and are not rolled back.
  4. Do not retry an outbound SIP POST /v1/live/sessions after a timeout. Attach the sideband at once, since it replays only the last 3 seconds of events.
  5. Keep the transport open until session.closed to read the final usage.seconds. A WebRTC session bills 15 seconds at creation, credited once it runs.

Hume EVI (Empathic Voice Interface)

  1. Create a config with a voice first, EVI 3 has no default
  2. Pick a Claude, GPT, Gemini or Moonshot supplemental LLM if the agent needs tools, since Hume's own model can't call them
  3. Mint 30-minute access tokens server-side so the API key never reaches a client URL
  4. Turn on 'Do not retain data' and 'Do not use for training' at app.hume.ai before sensitive calls
  5. Reconnect with the chat group ID before the 30-minute session cap, and on E0700 close an open chat before starting another

Questions

Which is better for AI agents, GPT-Live or Hume EVI (Empathic Voice Interface)?

GPT-Live scores 66.8 (B) on agent readiness against Hume EVI (Empathic Voice Interface)'s 56.7 (C), and leads in 5 of 7 scored categories. Hume EVI (Empathic Voice Interface) leads on payments & pricing.

Do GPT-Live and Hume EVI (Empathic Voice Interface) need an API key?

GPT-Live needs an API key. Hume EVI (Empathic Voice Interface) takes an API key or an OAuth sign-in.

Can an agent call GPT-Live and Hume EVI (Empathic Voice Interface) without installing anything?

Yes. GPT-Live has a hosted endpoint at https://api.openai.com/v1/live/sessions and Hume EVI (Empathic Voice Interface) at https://api.hume.ai/v0/evi.

Other comparisons with GPT-Live or Hume EVI (Empathic Voice Interface)

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