Head to head · Voice agents · October 2026 research run

Amazon Nova 2 Sonic vs Gemini Live API

Amazon Nova 2 Sonic scores 67.6 (B) on agent readiness against Gemini Live API's 54.1 (C), and leads in 4 of 7 scored categories. Gemini Live API leads on agent ergonomics, payments & pricing and maintenance & community. Both do voice agents.

Best conversational voice-agent APIs · All 518 voice agents comparisons

Which one, for what

Amazon Nova 2 Sonic B

Best for Voice agents on AWS, call centres on Amazon Connect, teams that want IAM and in-account data handling.

Ahead on

  • Reliability, 95 against 41
  • Schema & documentation, 75 against 66
  • Security & auth, 77 against 48
  • Transparency & trust, 79 against 72

Also in its favour

  • No incidents deducted, where Gemini Live API loses 3 points for them

Watch for

Connections end after 8 minutes, so long calls need the session-continuation pattern

Gemini Live API C

Best for Teams building their own voice or vision assistant on a single speech-to-speech model with function calling and Search grounding, who can run a backend for tokens and audio transport.

Ahead on

  • Agent ergonomics, 69 against 64
  • Payments & pricing, 40 against 10
  • Maintenance & community, 83 against 50

Also in its favour

  • A hosted endpoint, with nothing to install

Watch for

The WebSocket guide authenticates with the API key as a key query parameter, and ephemeral tokens as an access_token query parameter.

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Reliability Amazon Nova 2 Sonic +54

Amazon Nova 2 Sonic 95

Hosted reading. AWS Health Dashboard with per-service, per-Region history (20). The dashboard history file (newest event 30 October 2026) lists no Bedrock event in the 90 days from 8 August, and the 3 September us-west-2 event names STS, Connect and IAM Identity Center, not Bedrock. The public dashboard records broad events only, so 25 of 30, as amazon-nova-embeddings was read. Quotas published, 20 concurrent requests per Region, not adjustable (15). The stream API lists ThrottlingException (429), ServiceUnavailableException (503), ModelTimeoutException (408) and ModelStreamErrorException (424), Bedrock's troubleshooting guide advises backoff with jitter, and the 8-minute connection limit comes with a session-continuation sample (15). Bedrock's SLA of 99.9 per cent a month per Region for model APIs, as read for amazon-nova-embeddings on 1 November (10). Generally available since 2 December 2025 (10). 20 + 25 + 15 + 15 + 10 + 10 = 95.

Gemini Live API 41

Graded as a hosted API on the Gemini Developer API. A status page exists at aistudio.google.com/status, but on 4 November it still returned a script shell titled "Google AI Studio" with no components or history we could read (10 of 20, and 5 of 30 for the incident line with no readable record). Session limits are published, 15 minutes for audio and 2 for audio with video without compression, connections of about 10 minutes, and spend limits per 10 minutes of $10 on Tier 1 and $200 on Tiers 2 and 3. Per-model request limits and concurrent sessions are shown only in AI Studio, so the earlier partial 8 of 15 is kept. The server sends a GoAway message with timeLeft before closing, session resumption handles last 2 hours, and the troubleshooting guide gives exponential backoff with jitter for 429 and 503 (12 of 15). No SLA found for the Developer API (0). gemini-3.8-live is stable and generally available since 15 September, but the endpoint is v1beta, ephemeral tokens are in preview and the capabilities guide and API reference still label the Live API a preview, so the earlier partial 6 of 10 is kept.

Maintenance & community Gemini Live API +33

Amazon Nova 2 Sonic 50

Read as a model. The newest dated change is the May 2026 refresh, completed on 28 May, 162 days before this check (10). No Sonic release note or document history entry in the 90 days from 8 August. The pre-alpha Python SDK shipped 0.9.0, 0.10.0, 0.11.0 and 0.12.0 in the window, counted half (10 of 20). Release notes, document history, re:Post and AWS Support (10 of 15). The JavaScript Bedrock runtime client is current at 3.1163.0, while the Python route is pre-alpha (10 of 15). The SDKs ship on AWS's release train; CI not read (10). Total 50.

Gemini Live API 83

google-genai 2.34.0 (29 October 2026) changes the Live client, adding base_url, api_version and headers to LiveConnectConfig.http_options and a header fix in live.py, 6 days before the check (30). In the 90 days from 6 August, the changelog's gemini-3.5-transcribe-live (26 August) and 3.8 Live GA (15 September) entries, and Python SDK releases that change Live code, 2.18.0 (12 August), 2.19.0 (19 August), 2.23.0 (10 September), 2.26.0 (30 September), 2.30.0 (13 October), 2.32.0 (21 October), 2.33.0 (22 October) and 2.34.0 (29 October) (20). Closed service with a changelog updated several times a month. Support channels were not tested (10 of 15). Current official SDKs, google-genai v2.34.0 and @google/genai v2.32.0, both tagged 29 October (15). Apache-2.0 SDKs with type-check workflows in the Python repository and Node 20 or later stated. CI results were not read (8 of 10).

Payments & pricing Gemini Live API +30

Amazon Nova 2 Sonic 10

No x402, MPP or L402 (0). The Nova and Bedrock pricing pages carry a speech-to-speech table drawn by script, so the per-token prices weren't read and this line scores absent, which is our reader's limit and not the vendor's (0). New accounts get up to $200 in Free Tier credits, and the Free Tier FAQ says most new customers need no payment method, read as half on the other AWS listings (10). A person signs up for an AWS account in a browser (0). Total 10.

Gemini Live API 40

No x402, MPP or L402 (0 of 40). Per-token prices with per-minute equivalents are published without a login (20). The Live models are free of charge on the free tier, and the billing guide says new accounts start there with billing linked only to move to the paid tier (20). A key needs a Google account and AI Studio, so a person signs up in a browser (0).

Security & auth Amazon Nova 2 Sonic +29

Amazon Nova 2 Sonic 77

SigV4 with IAM roles and temporary credentials scoped per model ARN, as the Sonic quickstart signs (30). Tools run in the client, so side effects are the developer's to approve, and IAM can restrict which models a role invokes, with no approval step in the API (12 of 20). The model listens to callers and acts on tool results, and no prompt-injection guidance was found in the Sonic guide (5 of 15). CloudTrail logs Bedrock API calls, read as amazon-nova-embeddings was (12 of 15). VDP on HackerOne, Bedrock in SOC scope and a valid security.txt on aws.amazon.com, with no paid bounty, as on the other AWS listings (18 of 20). Total 77.

Gemini Live API 48

Keys created since 28 May 2026 are authorisation keys bound to a service account and restricted to the Gemini API, with IP and origin restrictions, a leak checklist and rejection of unrestricted standard keys. Ephemeral tokens add expiry and use counts (25 of 30). The WebSocket guide, re-read on 4 November, still documents the API key as a key query parameter and ephemeral tokens as an access_token query parameter, so we deduct 10 on that documentation (15 of 30). Ephemeral tokens can be locked to a model and configuration and to one session, which keeps system instructions server side. There is no approval step for tool calls, which the client runs itself (12 of 20). The model hears callers and can ground on Google Search, and the best practices page covers guardrails in system instructions but not prompt injection (5 of 15). Opt-in logs exist for billed projects, and we did not confirm they cover Live sessions. Usage is visible per project (8 of 15). security.txt on google.com valid to 2030 with a vulnerability reward programme. No certification naming the Developer API was found (8 of 20).

Schema & documentation Amazon Nova 2 Sonic +9

Amazon Nova 2 Sonic 75

The Bedrock service model types InvokeModelWithBidirectionalStream, but the Sonic events inside it (session, prompt, content, tool and usage events) are JSON payloads documented only in the guide, with no schema file (12 of 25). llms.txt and Markdown copies of the Nova 2 guide (10). Guides on the event lifecycle, barge-in, turn-taking, async tools and chat history say when and how to use each (16 of 20). Event fields are documented as JSON examples and tables, not typed schemas (10 of 15). Sample repositories in several languages and the API's exceptions with HTTP codes (12 of 15). Release notes and document history, with in-place model refreshes and a versioned model ID (15). Total 75.

Gemini Live API 66

No AsyncAPI or similar file for the WebSocket messages was found. The keyless Discovery document (revision 20261006) types auth_tokens.create and five related schemas, BidiGenerateContentSetup among them, but not the client and server messages (8 of 25). llms.txt with a Markdown twin of every page (10). The capabilities guide, model comparison table and best practices page say when to use each model, voice activity mode and tool behaviour (16 of 20). The reference at aistudio.google.com/api-reference/live lists every message with field types, enums such as ActivityHandling, TurnCoverage and the sensitivity levels, and required marks, as tables and not as a schema (12 of 15). Python and JavaScript examples on every guide, but no list of WebSocket close codes or Live error responses was found (8 of 15). Dated changelog and versioned model names, less 3 because the tools page omits the 3.8 models, the overview says 70 languages where the capabilities guide lists 99, and preview banners remain on two pages after general availability (12 of 15). Docs moved from ai.google.dev to aistudio.google.com by 4 November 2026; the pages not re-read stand per the 8 October check.

Transparency & trust Amazon Nova 2 Sonic +7

Amazon Nova 2 Sonic 79

Closed model under the AWS Service Terms, with Apache-2.0 SDKs and samples (15). Bedrock stores no inputs or outputs by default and model providers can't see them, Sonic isn't on the abuse-detection page's list of models whose traffic is stored, and section 50.3 doesn't list Bedrock among services whose content improves AWS services, as read for amazon-nova-embeddings on 1 November (22 of 30). Bedrock's lifecycle policy for models launched before 7 September 2026 promises 12 months and a Legacy period of at least 6 months, but the March and May refreshes changed the model in place under the same ID (15 of 20). Regions are listed, with sub-processors not read (12 of 20). Total 64.

Gemini Live API 72

Closed service with clear terms, SDKs under Apache-2.0 (15 of 30). The terms, pricing page and zero data retention page agree that free-tier content improves Google products and paid content does not. The terms say abuse logs are kept for a limited period and the abuse monitoring page gives 55 days. Session state is kept up to 24 hours when resumption is on, and Search grounding data 30 days (20 of 30). A deprecations table gives earliest shutdown dates and replacements, with 17 November 2026 for the two older Live previews, about nine weeks after the replacement shipped, and no stated minimum notice (15 of 20). The terms say data may be stored transiently or cached in any country where Google has facilities. The Data Processing Addendum applies to paid services, and no sub-processor list was read (5 of 20).

Score by category

CategoryWeight this runAmazon Nova 2 SonicGemini Live APIEdge
Reliability16%209541Amazon Nova 2 Sonic +54
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27566Amazon Nova 2 Sonic +9
Agent ergonomics13%16.26469Gemini Live API +5
Security & auth14%17.57748Amazon Nova 2 Sonic +29
Payments & pricing10%12.51040Gemini Live API +30
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.85083Gemini Live API +33
Transparency & trust7%8.87972Amazon Nova 2 Sonic +7
Negative events≤150-3
TotalB 67.6/100C 54.1/100

Facts side by side

FactAmazon Nova 2 SonicGemini Live API
KindHTTP APIHTTP API
VendorAmazon Web ServicesGoogle
Hosted endpointno (local only)https://generativelanguage.googleapis.com/v1beta
TransportsHTTPHTTP
AuthAPI keyAPI key
PricingPay per useFreemium
x402nono
LicencenoneProprietary service under the Gemini API Additional Terms of Service. The Python and JavaScript SDKs are Apache-2.0
Tools exposed0none
Read-only variant documentednono
llms.txtyesyes
Last release2026-05-282026-10-29
Terms last updated2026-10-012026-04-28
Privacy policy last updated2026-05-182026-10-01
Customer content may train modelsyes, with an opt-outyes
Terms restrict automated accessyesyes
Terms restrict benchmarkingyesyes
Terms or service can change without noticeyesnot found in the text
Arbitration or class-action waivernot found in the textnot found in the text
Popularitynone29.5M npm/wk, 34.1M PyPI/wk

How the scores have moved

Verdicts

Amazon Nova 2 Sonic

Nova 2 Sonic runs speech-to-speech conversations with asynchronous tools on Bedrock, with IAM scoping, no default storage of inputs and a 99.9 per cent SLA. Sessions cut off at 8 minutes, the Python SDK is pre-alpha, and the event payloads have no schema file. Prices are in a script-drawn table we couldn't read.

Gemini Live API

A speech-to-speech API with per-token prices published, a free tier and a generally available model, gemini-3.8-live, since 15 September 2026. The documented raw WebSocket connection carries the API key in the URL, connections reset about every 10 minutes, and no SLA or readable incident history was found for the Developer API.

Before you call either

Amazon Nova 2 Sonic

  1. Plan a reconnect before 8 minutes and replay chat history (up to 200 KB) at the start of the new session
  2. Send session, prompt and content start events in order before any audio
  3. Make tool calls safe to repeat, since a reconnect can replay them
  4. Back off on ThrottlingException and stay within 20 concurrent sessions per Region
  5. Use the polyglot voices TIFFANY or MATTHEW when callers may switch language

Gemini Live API

  1. Enable sessionResumption and keep the newest handle. Connections end after about 10 minutes, and handles stay valid for 2 hours.
  2. Set contextWindowCompression with a sliding window. Without it audio sessions stop at 15 minutes and audio with video at 2 minutes, and every turn re-bills the whole context.
  3. On gemini-3.8-live function calls are non-blocking by default. Set behavior: BLOCKING if the model must wait for the tool response.
  4. Keep the API key on a server and send it through the SDK. Give browsers an ephemeral token from POST /v1beta/auth_tokens, locked with liveConnectConstraints.
  5. Use google-genai 2.34.0 or later if you pass a per-request Authorization header. Earlier versions kept it in the client's default headers

Questions

Which is better for AI agents, Amazon Nova 2 Sonic or Gemini Live API?

Amazon Nova 2 Sonic scores 67.6 (B) on agent readiness against Gemini Live API's 54.1 (C), and leads in 4 of 7 scored categories. Gemini Live API leads on agent ergonomics, payments & pricing and maintenance & community.

Do Amazon Nova 2 Sonic and Gemini Live API need an API key?

Both need an API key.

Can an agent call Amazon Nova 2 Sonic and Gemini Live API without installing anything?

No hosted endpoint is listed for Amazon Nova 2 Sonic. Gemini Live API has a hosted endpoint at https://generativelanguage.googleapis.com/v1beta.

Other comparisons with Amazon Nova 2 Sonic or Gemini Live API

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