2026-09-17, Copilot · SERP API

Is there a Microsoft Copilot API? Every option for getting Copilot answers in 2026

Microsoft has several APIs with “Copilot” or Bing grounding in the name, but none of them, as documented on Microsoft’s own pages (checked 2026-09-17), returns the answer the free consumer Microsoft Copilot gives to a prompt. The Microsoft 365 Copilot APIs work on a licensed organization’s tenant. Copilot Studio and Foundry let you build your own agent grounded in Bing. The Bing Search APIs are retired. If you need the consumer Copilot answer with its citations, for monitoring or research, you have to collect that answer from Copilot itself.

Below, each option is mapped to what it returns. For a step-by-step tutorial on the last option, see monitor Microsoft Copilot answers with an API.

First, which Copilot?

“Copilot” names several Microsoft products. Microsoft Support’s comparison of Copilot experiences (checked 2026-09-17) separates:

• Microsoft Copilot (free), available at copilot.microsoft.com, as desktop and mobile apps, and in Edge, for “general questions and answers” and “real-time answers based on web search”.
• Copilot in eligible individual Microsoft 365 plans.
• Copilot Chat, included for organizations with an eligible Microsoft 365 license, and the Copilot add-on license for organizations.

The consumer product’s Transparency Note (for individuals signed in with a Microsoft account; dated August 18, 2026) says that for information-seeking conversations Copilot “is grounded in web search results” and provides hyperlinked citations after its text responses. That consumer answer is what brand and GEO teams usually want to measure.

The options at a glance

The sections below give Microsoft’s own description of each, with sources.

Microsoft 365 Copilot APIs

Microsoft’s Copilot APIs overview (checked 2026-09-17) describes a family of REST APIs under the Microsoft Graph namespace (graph.microsoft.com/v1.0/copilot and /beta/copilot) that “provide access to components that power Microsoft 365 Copilot experiences”. They include the Retrieval API, a Search API over OneDrive content (preview), an Interaction Export API for compliance, a Meeting Insights API, usage reports, package management and the Chat API.

Requirements, per the same page: a Microsoft 365 Copilot license for each user who accesses the functionality, on top of an E3 or E5 subscription or equivalent, with authentication through Microsoft Entra ID on behalf of a signed-in user.

Chat API (preview)

The Chat API overview says it lets you “programmatically engage in multi-turn conversations with Microsoft 365 Copilot while using enterprise search grounding and web search grounding”. Documented details that matter for evaluation:

• It is available at no extra cost to users with a Microsoft 365 Copilot add-on license; “support for users without a Microsoft 365 Copilot add-on license isn’t currently available”.
• It uses enterprise search grounding and web search grounding by default; turning web grounding off is a per-message action.
• It “only responds with textual responses” and doesn’t support action skills, code interpreter or long-running tasks.
• Synchronous and streamed (server-sent events) endpoints exist.

It fits internal applications for licensed employees. It won’t show what the free consumer Copilot tells the public about your brand: it runs as a work user in your tenant, with your organization’s data and policies in play, and Microsoft doesn’t document it as reproducing the consumer experience.

Retrieval API

The Retrieval API overview says it returns “relevant text chunks from the hybrid index that powers Microsoft 365 Copilot”, from SharePoint, OneDrive and Copilot connectors. It supports KQL filters, is available to Microsoft 365 Copilot-licensed users, and offers pay-as-you-go consumption (preview) for tenant-level sources for users without that license. It does not retrieve from the public web, so it is irrelevant to public AI answers.

Copilot Studio

Copilot Studio builds custom agents. Its knowledge sources summary (checked 2026-09-17) says the Web Search setting “searches all public websites indexed by Bing” and uses Grounding with Bing Search, and that public website knowledge sources search the query on Bing and return results only from the websites you provide.

That gives you an agent with your instructions, your knowledge sources and Bing results. A different system prompt, orchestration and set of sources produce a different answer from consumer Copilot’s.

Microsoft Foundry: Web Search and Grounding with Bing Search

For developers on Azure, Microsoft’s web grounding overview (checked 2026-09-17) describes two generally available tools in Foundry Agent Service:

• Web Search (recommended): no separate Bing resource, user_location and search_context_size parameters, Azure OpenAI models.
• Grounding with Bing Search: you create a Grounding with Bing Search resource; parameters include count, freshness, market and set_lang; supports Azure OpenAI models and other models sold by Azure.
• Grounding with Bing Custom Search (preview) restricts results to domains you configure.

The Grounding with Bing Search tools page lists limits worth knowing before you build on it:

• The tools “don’t return the tool output to developers and end users”. You get your model’s response with citations and no result list.
• Microsoft’s use and display requirements apply to the website URLs and Bing search query URLs shown with responses.
• Data sent to these services flows outside the Azure compliance and geo boundary, and the Microsoft Data Protection Addendum doesn’t apply to it.
• Usage incurs costs beyond model usage.

Foundry therefore gives you a Bing-grounded answer from your own model. That can support a study of what a Bing-grounded model says, but it is a different answer from consumer Copilot’s, and it doesn’t expose Bing’s ranked results.

The Bing Search APIs are retired

Microsoft’s lifecycle notice (checked 2026-09-17) states that the Bing Search APIs were retired on August 11, 2025: existing instances were decommissioned and the product is no longer available for use or new signup. Microsoft directs customers to Grounding with Bing Search. If you’re evaluating replacements for raw search results rather than AI answers, see best SERP APIs and the web search API use case.

Bing Webmaster Tools AI Performance

This is a reporting tool for publishers rather than an answer API. The February 10, 2026 announcement says the report shows “how publisher content appears across Microsoft Copilot, AI-generated summaries in Bing, and select partner integrations”, with total citations, average cited pages per day, page-level citation counts, trends, and “grounding queries”, described as a sample of the key phrases the AI used when retrieving content that was cited.

It answers “how often are my pages cited, and for which phrases?” for a site you’ve verified. It can’t show the answer text, whether your brand was named without a link, which competitors were cited on the same prompts, or data for sites you don’t own. Use it alongside answer monitoring.

Decision guide

Getting consumer Copilot answers with this API

This API returns Microsoft Copilot’s answer as JSON. A request takes a prompt and a country, optionally a US state:

curl -X POST https://api.answerline.dev/v1/monitor/copilot \
  -H "Authorization: Bearer $ANSWERLINE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "prompt": "best payroll software for a 50-person company", "country": "US" }'

The response is { "success": true, "result": { ... } } with:

For recurring monitoring, submit the same body as an async task with taskType: "COPILOT" and a webhook:

import os
import requests

API = "https://api.answerline.dev"
HEADERS = {"Authorization": f"Bearer {os.environ['ANSWERLINE_API_KEY']}"}

task = {
    "taskType": "COPILOT",
    "payload": {"prompt": "best payroll software for a 50-person company", "country": "US"},
    "idempotencyKey": "copilot-payroll-50-US-2026-09-17",
    "webhook": {"url": "https://example.com/hooks/answers"},
}
resp = requests.post(f"{API}/v1/async/task", json=task, headers=HEADERS, timeout=60)
resp.raise_for_status()
print(resp.json()["task"]["id"])

Cost: 5 credits per Copilot async task, 7 for a synchronous call (a 2-credit synchronous surcharge). The markdown, html and rawResponse flags and the automatic searchQueries add nothing. The free plan includes 500 credits per month, enough for 100 async Copilot answers; plans are on /pricing.

The full walkthrough, including field details, batching, idempotency keys and metrics, is in monitor Microsoft Copilot answers.

What to measure once you have answers

• Mention rate: share of answers whose text names your brand.
• Citation rate: share of answers with your domain in sources.
• Competitor share: which domains take the remaining citations, per prompt group.
• Search overlap: which of Copilot’s searchQueries recur across prompts, and whether your pages are the natural result for them.

Run the same prompts on ChatGPT, Gemini and Grok for comparison; engines differ in what they cite, and AI grounding by engine shows how to measure where the differences come from. For how the vendors document retrieval and citations overall, see the AI search engines.

Pitfalls

• “Copilot API” in a vendor pitch or tutorial usually means the Microsoft 365 Copilot APIs, which run on a licensed tenant. Check which product is meant.
• Bing Search API tutorials from before August 2025 describe retired endpoints.
• Results from a Foundry agent come from your model with Bing grounding. Label them that way, not as Copilot results.
• Copilot’s citations can change between runs, so trend repeated runs (answer volatility).
• Pass country, and state for US prompts, consistently.

Field list and a request example are on the Copilot engine page; make a first call with the quickstart.

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