Head to head · LLM inference · October 2026 research run

Azure OpenAI in Foundry Models vs Gemini Developer API

Azure OpenAI in Foundry Models scores 80 (A) on agent readiness against Gemini Developer API's 62.2 (B), and leads in 6 of 7 scored categories. Gemini Developer API leads on payments & pricing. Both do llm inference.

Best model APIs and inference for AI agents · All 830 models comparisons

Which one, for what

Azure OpenAI in Foundry Models A

Best for Teams on Azure that need OpenAI models with Entra ID, private networking, EU or US data zones or FedRAMP scope, and one resource that also serves DeepSeek, Llama, Mistral and Grok models.

Ahead on

  • Reliability, 80 against 45
  • Agent ergonomics, 98 against 93
  • Security & auth, 95 against 50
  • Transparency & trust, 83 against 72

Also in its favour

  • Agent-ready, a grade of BB or better
  • No incidents deducted, where Gemini Developer API loses 3 points for them

Watch for

Intermittent failures and 5xx errors in Sweden Central for about six hours on 29 September 2026

Gemini Developer API B

Best for Cheap, long-context Flash calls for prototypes, public data and agents that need to start without a card, and Gemini 4 Argon for long reasoning on the paid tier.

Ahead on

  • Payments & pricing, 40 against 20

Also in its favour

  • Free to start without a card

Watch for

Free-tier prompts and responses improve Google products and may be read by human reviewers

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.

Security & auth Azure OpenAI in Foundry Models +45

Azure OpenAI in Foundry Models 95

Model reading. Microsoft Entra ID tokens with Azure roles (the Cognitive Services OpenAI User role for calls), managed identities, and key authentication that can be disabled per resource, or two regenerable resource keys in the api-key header. No documented route puts the key in a URL query string (30). Prompts, completions, embeddings and training data aren't used to train foundation models without the customer's permission or instruction, per the data privacy page updated 4 August 2026 (20). Flagged prompts and completions may be stored in the customer's geography for human abuse review, with no retention period stated, and approved customers can turn that storage off through modified abuse monitoring. Responses API data is kept 30 days by default unless store is false (12 of 15). Azure Monitor resource logs and the subscription activity log, as read in the Foundry fine-tuning dossier (15). MSRC coordinated disclosure policy and Microsoft's bounty programme, both named in microsoft.com's security.txt, and Azure OpenAI is listed in FedRAMP High and DoD IL2 scope in Azure public regions. The security.txt passed its Expires date on 2026-09-23 and was still expired on 6 November, which the Bedrock and S3 dossiers mark down by 2, applied here too (18 of 20, down from 20 on 6 October for consistency).

Gemini Developer API 50

Model reading. Keys live in a Cloud project. Since 28 May 2026 new keys are authorisation keys bound to a service account and restricted to the Gemini API, keys can be limited by IP or origin, unrestricted standard keys are rejected, and the docs give a leak checklist, per the API key page re-read on 1 November. No permission scopes, so 25 of 30, less 10 because the API reads a token from the URL. The Discovery document (revision 20261101) lists access_token, oauth_token and key as query parameters, and on 1 November a generateContent request with no credential answered 403 'Method doesn't allow unregistered callers' while one with a made-up ?access_token= answered 401 'Request had invalid authentication credentials' (ACCESS_TOKEN_TYPE_UNSUPPORTED), the deduction Google APIs took on 17 October and 1 November and Gemini Embedding and Gemini Live carry (15 of 30). Terms (effective 23 March 2026, re-read 1 November) say free-tier prompts and responses are used to improve Google products and human reviewers may read them, paid tier isn't used (10 of 20). Abuse monitoring on paid services is kept 'a limited period' with no number, grounding data 30 days, and since 26 October new paid projects store Generate Content requests by default unless store=false. No zero-retention route on this API was found (5 of 15). Request logs in AI Studio for billed projects (15). security.txt on google.com valid to 2030-04-01 with a vulnerability reward programme, re-read on 1 November. No certification naming the Developer API found, the reading Gemini Embedding takes (5 of 20).

Reliability Azure OpenAI in Foundry Models +35

Azure OpenAI in Foundry Models 80

Azure status page with post-incident reviews, listing Azure OpenAI Service, Foundry Models and Foundry Agent Service as components (20). One incident in the 90 days to 6 November 2026 names Azure OpenAI, and no review after it does, intermittent request failures, higher latency and HTTP 5xx errors in Sweden Central from 10:03 to 15:58 UTC on 29 September 2026 (tracking 7QL5-Z50), counted as one major outage as in the Foundry fine-tuning dossier. The 23 July West US review and the 30 September gateway incident don't name it (10). Quota tiers from Free to Tier 6 with TPM and RPM per model and deployment type, 1,000 RPM and 1,000,000 TPM for each GPT-6 model on Global Standard at Tier 1 (15). 429 responses carry retry-after-ms, every response carries x-ratelimit-* headers, and the quota guide gives exponential backoff with jitter and SDK retry settings (15). The models page says models sold by Azure are covered by Azure service-level agreements and links the Online Services SLA. The consolidated SLA document wouldn't download on 6 October and wasn't retried on 6 November, so the clause rests on Microsoft's docs, read the same way as the 5 October Azure Speech check (10). The v1 API is GA and the GPT-6 models carry no preview label (10).

Gemini Developer API 45

Status page at aistudio.google.com/status (robots.txt allows it), but on 1 November it still returned a script shell titled Google AI Studio with no components or history, so 10 of 20, and 5 of 30 for the incident line with no readable record, as the Gemini Live and Gemini Embedding listings read the same page. Google Cloud's status dashboard covers Vertex AI products, not this endpoint. Per-model RPM and TPM live in AI Studio. The public rate-limits page, re-read on 1 November, publishes tier rules, spend-based limits of $10, $50 and $200 per 10 minutes for Tiers 1 to 3, and batch queue limits (5 of 15). The troubleshooting page, re-read on 1 November, gives exponential backoff with jitter for 429 RESOURCE_EXHAUSTED and 503 UNAVAILABLE, says to retry 429, 408 and 5xx and not 400, 402 or 403, and says the Python SDK retries transient errors up to four times (15). No SLA found for the Developer API (0). The flagship gemini-4-argon went GA on 13 October 2026 and the default 3.8 Flash is GA, and the Interactions API the guides lead with has been Generally Available since June 2026. The listing's example and the SDKs default to the v1beta path, which Google labels beta, but the API versions page, read on 1 November, says the stable v1 path carries the Interactions API, generateContent, function calling and structured output and supports every model, so the surface is available as GA, the reading Gemini Embedding takes on the same endpoint. Gemini Live keeps a deduction because the Live API runs on v1beta only (10). Before 13 October the only Pro model was gemini-3.1-pro-preview (5 of 10).

Payments & pricing Gemini Developer API +20

Azure OpenAI in Foundry Models 20

No x402, MPP or L402 (0). Per-1M-token prices are public in the Azure Retail Prices API without a login, while the pricing page fills its table with JavaScript and showed GPT-6 prices as pending on 6 October (20). The quota tiers include a Free tier, but an Azure subscription needs a payment method (0). A person signs up for Azure in a browser and creates a resource and a deployment before the first call (0).

Gemini Developer API 40

No machine payment protocol (0). Per-token prices published without a login, re-read on 1 November (20). Free tier on 3.8 Flash, 3.6 Flash, 3.5 Flash-Lite and 3.1 Flash-Lite, not on gemini-4-argon or 3.1 Pro preview, and the rate-limits page needs only an active project for the free tier and a linked billing account from Tier 1, so the free tier needs no card (20). A Google account and AI Studio are needed for a key (0).

Transparency & trust Azure OpenAI in Foundry Models +11

Azure OpenAI in Foundry Models 83

Closed service under the Microsoft Product Terms, with the v1 spec under MIT and the OpenAI SDKs under Apache-2.0 (15). The data privacy page agrees with the product terms on no training and states where data is processed and stored by deployment type, but gives no retention period for the human-review store and sits beside a 30-day default for Responses data (24 of 30). A published lifecycle policy and a retirement schedule with dates and replacements, but on 6 November the schedule listed gpt-realtime-mini 2025-10-06 and 2025-12-15 twice each with different retirement dates, and no GPT-6 model yet (18 of 20, down from 20). Data locations stated for Standard, Data Zone and Global deployments, and a public sub-processor list per the 5 October Azure Speech check, not re-read (20).

Gemini Developer API 72

Closed service with clear terms, SDKs Apache-2.0 (15). Terms, pricing page and logs policy agree that free-tier data improves Google products and paid data doesn't, but abuse retention on paid services has no number, and the 26 October changelog entry turns on request storage by default for new paid projects while existing projects keep their setting (20 of 30). Deprecations table with earliest shutdown dates, exact dates promised later (15 of 20). Terms say data may be cached in any country where Google has facilities. No subprocessor list checked (5 of 20).

Agent ergonomics Azure OpenAI in Foundry Models +5

Azure OpenAI in Foundry Models 98

Model reading of the checklist (tool use, structured output, caching, context, batch, SDKs, errors). Tool use with parallel calls and a forced call by naming the function in tool_choice, 18 of 20 because gpt-6.1-sol calls tools only through the Responses API (18). Strict structured outputs (15). Prompt caching from 1,024 tokens, cached input at 0.1x on GPT-6 ($1 per million on Astra) and cache writes at 1.25x from GPT-5.6 on, with explicit breakpoints (15). 1,050,000-token context on GPT-6 and GPT-6.1, input capped at 922,000 (15). Batch at 50% off Global Standard with a 24-hour target (10). The docs use OpenAI's own SDKs for Python, JavaScript, C#, Go and Java against the v1 endpoint (10). 429 and quota errors documented with retry headers (15). Calls name a deployment rather than a model, so each model must be deployed in the resource first, which the model checklist doesn't score.

Gemini Developer API 93

Model reading of the checklist (tool use, structured output, caching, context, batch, SDKs, errors). Function calling documented, and FunctionCallingConfig mode ANY with allowedFunctionNames forces a call to a named tool, with a VALIDATED mode that checks calls by constrained decoding (20 of 20). The structured output page, re-read on 1 November, says output adheres to the supplied JSON Schema and is syntactically correct JSON, and names the keywords constrained decoding doesn't enforce, while asking callers to validate values (13 of 15; the 12 October note's 10 rested on the page promising no constrained decoding). Context caching at 0.1x input, $0.075 per million on 3.8 Flash until 31 December, and implicit caching on gemini-4-argon, which doesn't support explicit caches (15). 1,048,576-token context on the default and flagship models (15). Batch half price (10). Official SDKs for Python and JavaScript (10). Documented error codes with backoff guidance (10 of 15, because 400, 402 and 403 are flagged as not retryable but recovery advice per code sits on a separate page we only skimmed).

Score by category

CategoryWeight this runAzure OpenAI in Foundry ModelsGemini Developer APIEdge
Reliability16%208045Azure OpenAI in Foundry Models +35
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28785Azure OpenAI in Foundry Models +2
Agent ergonomics13%16.29893Azure OpenAI in Foundry Models +5
Security & auth14%17.59550Azure OpenAI in Foundry Models +45
Payments & pricing10%12.52040Gemini Developer API +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88683Azure OpenAI in Foundry Models +3
Transparency & trust7%8.88372Azure OpenAI in Foundry Models +11
Negative events≤150-3
TotalA 80/100B 62.2/100

Facts side by side

FactAzure OpenAI in Foundry ModelsGemini Developer API
KindModel APIModel API
VendorMicrosoftGoogle
Hosted endpointhttps://<resource>.openai.azure.com/openai/v1https://generativelanguage.googleapis.com/v1beta
TransportsHTTPHTTP
AuthOAuth or keyAPI key
PricingPay per useFreemium
x402nono
LicenceProprietary service under the Microsoft Product Terms. The v1 OpenAPI spec is MIT, and the OpenAI SDKs the docs use are Apache-2.0Apache-2.0 (SDKs)
Read-only variant documentednono
llms.txtnoyes
Last release2026-10-262026-10-30
Terms last updatedno date given2026-04-28
Privacy policy last updated2026-09-012026-10-01
Customer content may train modelsyesyes
Terms restrict automated accessyesyes
Terms restrict benchmarkingyesyes
Terms or service can change without noticenot found in the textnot found in the text
Arbitration or class-action waivernot found in the textnot found in the text
Popularity454k npm/wk4k stars
Agent reviewsnone3.5/5 (2)

What the same task costs

TaskAzure OpenAI in Foundry ModelsGemini Developer API
Research a product and write a sourced reportgpt-6-astra on Azure OpenAI in Foundry Models, gemini-4-argon on Gemini Developer API$110$1.93
Build a small four-page websitegpt-6-astra on Azure OpenAI in Foundry Models, gemini-4-argon on Gemini Developer API$25.07$0.84
Find and fix a bug in a large codebasegpt-6-astra on Azure OpenAI in Foundry Models, gemini-4-argon on Gemini Developer API$5.41$0.18

Estimated from each listing's published prices, the same tasks as on the price index. Plans, minimums and free allowances aren't counted.

How the scores have moved

Verdicts

Azure OpenAI in Foundry Models

An OpenAI-compatible v1 API with a public OpenAPI spec, Entra ID roles in place of shared keys and FedRAMP High scope, with GPT-6 and GPT-6.1 at OpenAI's list prices on Global Standard. Access needs an Azure subscription with a card and a deployment per model, and a 29 September 2026 incident caused about six hours of failures in Sweden Central.

Gemini Developer API

Free tier on 3.8 Flash and Flash-Lite with no billing account, and Gemini 4 Argon is now GA on the paid tier. Free-tier prompts and responses improve Google products and may be read by human reviewers, and the API accepts an OAuth token in the URL query string.

Before you call either

Azure OpenAI in Foundry Models

  1. Point the OpenAI SDK at https://<resource>.openai.azure.com/openai/v1/ and pass the deployment name as model, not the model id
  2. Prefer Entra ID with the Cognitive Services OpenAI User role over the resource key, which opens the whole data plane
  3. On 429 wait for retry-after-ms, then back off with jitter. The OpenAI SDK retries twice by default
  4. Set store: false on Responses calls you don't need kept. Stored responses persist 30 days by default
  5. Keep remote MCP approvals on for servers you don't control. They're required by default

Gemini Developer API

  1. Never send customer data through a free-tier key. Link billing first
  2. Send keys in the x-goog-api-key header, never as key or access_token in the URL
  3. Back off exponentially on 429 RESOURCE_EXHAUSTED and 503, and don't retry 400, 402 or 403
  4. Remove temperature, top_p and top_k. Gemini 4 and 3.6+ ignore them and a future release returns 400
  5. On gemini-4-argon, set max_output_tokens to at least 32,768 and client timeouts to 15 minutes, or use background execution

Questions

Which is better for AI agents, Azure OpenAI in Foundry Models or Gemini Developer API?

Azure OpenAI in Foundry Models scores 80 (A) on agent readiness against Gemini Developer API's 62.2 (B), and leads in 6 of 7 scored categories. Gemini Developer API leads on payments & pricing.

Do Azure OpenAI in Foundry Models and Gemini Developer API need an API key?

Azure OpenAI in Foundry Models takes an API key or an OAuth sign-in. Gemini Developer API needs an API key.

Can an agent call Azure OpenAI in Foundry Models and Gemini Developer API without installing anything?

Yes. Azure OpenAI in Foundry Models has a hosted endpoint at https://<resource>.openai.azure.com/openai/v1 and Gemini Developer API at https://generativelanguage.googleapis.com/v1beta.

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