<!-- twin of https://specstream.ai/bing-search/promptflow -->
# Prompt flow after the Bing Search API: one url to change

Compared on Nov 12, 2026. The page: https://specstream.ai/bing-search/promptflow

Prompt flow's `BingConnection` has two fields, `api_key` and `url`, and `url` defaults to `https://api.bing.microsoft.com/v7.0/search`. Microsoft retired that API on August 11, 2025, so a flow tool that calls it gets no results.

Set `url` to `https://api.specstream.ai/v7.0/search` and put a SpecStream key in `api_key`. Your tool sends the same call and reads the same JSON, at $1 per 1,000 searches. We ran it on promptflow-core 1.18.5 on Nov 12, 2026.

[Get an API key](https://specstream.ai/signup?src=alternatives-bing-search-promptflow&utm_source=alternatives-md&utm_campaign=bing-search-promptflow&returnTo=%2Fworkspace%2Fsearch%3Froute%3Dbing) New accounts get $10 of credit, no card. It covers 10,000 searches.

## Prompt flow web search and what replaces Bing, from each company's own pages on Nov 12, 2026

| | SpecStream | Bing Web Search API | Grounding with Bing Search | SerpApi (Prompt flow's Serp API tool) |
|---|---|---|---|---|
| Setting in Prompt flow | `url: https://api.specstream.ai/v7.0/search` in the `BingConnection` or a custom connection, with a SpecStream key in `api_key` | `BingConnection.url` default: `https://api.bing.microsoft.com/v7.0/search` | Not a v7 address. Microsoft places it in Azure AI Agents | The built-in Serp API tool, with a Serp connection that holds only an API key |
| Open to a new account | Yes. Create a key and start with $10 of credit, no card | No. Retired on August 11, 2025, with every instance decommissioned and no new sign-up | Yes, with a Grounding with Bing Search resource in the Azure portal | Yes. The Free plan holds 250 searches a month |
| Price | $1 per 1,000 searches of up to 10 results, with no monthly plan | None. Microsoft decommissioned the product | $14 per 1,000 transactions | $25 a month for 1,000 searches on Starter, up to $275 a month for 30,000 on Big Data |
| Limit | No limit per key and no daily limit. A busy call gets a `429` and is not charged | None. The API is retired | 150 transactions a second and 1 million a day | The plan's searches a month, and 200 an hour on Starter |
| What comes back | Bing's `webPages.value[]` with `name`, `url` and `snippet`, the fields a Bing tool already reads | `webPages.value[]`, with the name, URL and snippet of each page | No raw results: developers and end users get no access to the content returned | SerpApi's own JSON, a different shape from Bing's |
| What answers the search | The whole live web, read at the moment of the call. 97.9 F-score on all 1,000 SimpleQA Verified questions | Nothing since August 11, 2025 | An answer from the model. Not all models support it | Google, Bing or another engine, chosen by the tool's `engine` input |

## Why Prompt flow developers point Bing search at SpecStream

### The url field of BingConnection

Prompt flow declares the connection in `promptflow/connections/__init__.py`:

```
@dataclass
class BingConnection:
    api_key: Secret
    url: str = "https://api.bing.microsoft.com/v7.0/search"
```

Prompt flow ships no Bing tool of its own: the call is in a Python tool you wrote, which takes the connection as an input. We ran a tool of this shape. It reads `connection.url`, so it needs no change:

```
import requests
from promptflow.core import tool
from promptflow.connections import BingConnection


@tool
def bing_search(connection: BingConnection, question: str) -> list:
    reply = requests.get(
        connection.url,
        headers={"Ocp-Apim-Subscription-Key": connection.api_key},
        params={"q": question, "count": 10},
        timeout=60,
    )
    reply.raise_for_status()
    return reply.json()["webPages"]["value"]
```

Change the connection, in the connections file your run reads (the `dev-connections.json` form in Prompt flow's repository):

```
"bing_connection": {
  "type": "BingConnection",
  "module": "promptflow.connections",
  "value": {
    "api_key": "<your SpecStream key>",
    "url": "https://api.specstream.ai/v7.0/search"
  }
}
```

On Nov 12, 2026 we ran this flow with promptflow-core 1.18.5. The node finished with status `Completed` and returned the pages of `webPages.value`, each with its `name`, `url` and `snippet`.

### A custom connection, the way the pf CLI stores it

The local `pf connection` store holds connection types such as `custom`, and a Microsoft answer on Q&A recommends a custom connection for a Bing key. Put the address in `configs` and the key in `secrets`:

```
$schema: https://azuremlschemas.azureedge.net/promptflow/latest/CustomConnection.schema.json
name: bing_search
type: custom
configs:
  url: "https://api.specstream.ai/v7.0/search"
secrets:
  api_key: "<your SpecStream key>"
```

```
pf connection create -f bing_search.yaml --set secrets.api_key=$SPECSTREAM_API_KEY
```

A tool that takes a `CustomConnection` reads `connection.configs["url"]` and `connection.secrets["api_key"]` and sends the same `GET`. We ran that tool too on Nov 12, 2026, with status `Completed`.

### The same request and the same JSON

SpecStream answers `GET /v7.0/search` with `q`, `count` and `offset` in Bing's shape, with the key in `Ocp-Apim-Subscription-Key`. Every parameter and field of the route is in the [Bing Web Search v7 guide](https://specstream.ai/migrate/bing-web-search-v7?utm_source=alternatives&utm_campaign=bing-search-promptflow), and what Microsoft ended, and when, is on the [Bing Search API retirement](https://specstream.ai/bing-search-api-retirement?utm_source=alternatives&utm_campaign=bing-search-promptflow) page.

### $1 per 1,000 searches, with no daily limit

A search of up to 10 results costs $0.001. There is no monthly plan and no daily limit. Credit you buy never expires, and a new account starts with $10 of credit, which covers 10,000 searches. A busy call gets a `429` with `Retry-After` and charges nothing.

### The most accurate web search API, in about one second

On SimpleQA Verified the SpecStream Search API scores 97.9 F-score on all 1,000 official questions, 978 of them correct. On WideSearch it scores 64.0 item F1 and 43.4 row F1 on all 200 official tasks. Every score and its method is on the [benchmarks](https://specstream.ai/benchmarks?utm_source=alternatives&utm_campaign=bing-search-promptflow) page.

Every Bing call runs the fast search. Measured on production on November 9, 2026, its median was 0.82 s at 1 search a second and 1.07 s at 20 a second, and it answered 718 of 720.

### The same key after Prompt flow retires

Microsoft retires Prompt flow in Microsoft Foundry and Azure Machine Learning on April 20, 2027 and asks you to move to Microsoft Agent Framework. Your search tool is a plain HTTP call, so it moves with you: the same address and the same key work from any Python code, as the [Bing Search API in Python](https://specstream.ai/bing-search-api-python?utm_source=alternatives&utm_campaign=bing-search-promptflow) page shows.

## Other web search options for Prompt flow

### Grounding with Bing Search

Microsoft's named replacement for the Bing Search APIs, at $14 per 1,000 transactions, inside Azure AI Agents. It returns an answer with citations, and developers get no access to the raw results, so a Prompt flow tool has no `webPages.value` to read. SpecStream returns Bing's `webPages.value[]` at $1 per 1,000.

### Prompt flow's Serp API tool

The built-in tool wraps SerpApi's Google and Bing results. SerpApi sells plans from $25 a month for 1,000 searches, and the tool returns SerpApi's JSON, so a flow written for Bing's fields needs new parsing. SpecStream keeps your Bing tool and its fields, at $1 per 1,000 with no plan.

### Google Custom Search JSON API

$5 per 1,000 queries after 100 free a day, up to 10,000 a day, for existing customers only: Google closed it to new customers and ends it on January 1, 2027. It answers a different request with a different reply. SpecStream keeps your Bing call and costs $1 per 1,000, with no daily limit.

## How to move Prompt flow web search to SpecStream

1. Create a key under Agents & API in the SpecStream workspace. A new account gets $10 of credit, no card, which covers 10,000 searches.

2. Check the key with the call Bing's v7 API takes. A `200` with `webPages.value` means the key works.

```
curl -H "Ocp-Apim-Subscription-Key: $SPECSTREAM_API_KEY" \
  "https://api.specstream.ai/v7.0/search?q=test&count=3"
```

3. Set `url` to `https://api.specstream.ai/v7.0/search` and `api_key` to your SpecStream key: in the `BingConnection` of your connections file, or in a custom connection made with `pf connection create`.

4. Run the flow as before. Each search shows in your SpecStream request log with its price.

## Frequently asked questions

### Why does Bing search fail in my Prompt flow?

Microsoft retired the Bing Search APIs on August 11, 2025 and decommissioned every instance, so `https://api.bing.microsoft.com/v7.0/search`, the default `url` of `BingConnection`, answers no search. Set `url` to `https://api.specstream.ai/v7.0/search` with a SpecStream key in `api_key`.

### Where do I get a Bing API key for Prompt flow now?

Not from Microsoft: Bing has taken no new customer sign-up since August 11, 2025. Create a SpecStream key with $10 of credit, no card, and use it as the connection's `api_key`.

### Does Prompt flow have a built-in Bing tool?

No. `BingConnection` is a connection type for a Python tool you write, and the built-in search tool is the Serp API tool, which calls SerpApi. A Bing tool that reads `connection.url` works with SpecStream with no code change.

### What is the best Bing alternative for Prompt flow?

SpecStream, at $1 per 1,000 searches with no daily limit and 97.9 F-score on all 1,000 SimpleQA Verified questions. It answers the Bing call your tool already makes, in Bing's JSON.

### How much does Prompt flow web search cost with SpecStream?

$0.001 a call for up to 10 results. The first $10 of credit covers 10,000 searches, and credit you buy never expires.

### What happens to my search tool when Prompt flow retires?

Prompt flow retires on April 20, 2027. The tool is a plain HTTP call, so the same SpecStream address and key keep working in Microsoft Agent Framework or any Python code.

## Sources

SpecStream wrote this page. Prompt flow's settings come from its source on GitHub, and each provider's figure from that company's own page.

- [Prompt flow connections/__init__.py](https://raw.githubusercontent.com/microsoft/promptflow/main/src/promptflow-core/promptflow/connections/__init__.py), read Nov 12, 2026
- [Prompt flow dev-connections.json.example](https://raw.githubusercontent.com/microsoft/promptflow/main/src/promptflow/dev-connections.json.example), read Nov 12, 2026
- [Prompt flow: manage connections](https://raw.githubusercontent.com/microsoft/promptflow/main/docs/how-to-guides/manage-connections.md), read Nov 12, 2026
- [Prompt flow README](https://raw.githubusercontent.com/microsoft/promptflow/main/README.md), read Nov 12, 2026
- [Prompt flow Serp API tool reference](https://raw.githubusercontent.com/microsoft/promptflow/main/docs/reference/tools-reference/serp-api-tool.md), read Nov 12, 2026
- [Serp API tool for flows in Microsoft Foundry](https://learn.microsoft.com/en-us/azure/ai-foundry/how-to/prompt-flow-tools/serp-api-tool), read Nov 12, 2026
- [Microsoft Q&A: Bing web search API with Azure AI Studio](https://learn.microsoft.com/en-us/answers/questions/1615644/how-to-use-bing-websearch-api-with-azure-ai-studio), read Nov 12, 2026
- [Bing Search API retirement](https://learn.microsoft.com/en-us/lifecycle/announcements/bing-search-api-retirement), read Nov 12, 2026
- [Grounding with Bing Search pricing](https://www.microsoft.com/en-us/bing/apis/grounding-pricing), read Nov 12, 2026
- [Bing APIs](https://www.microsoft.com/en-us/bing/apis), read Nov 12, 2026
- [Grounding with Bing Search tools](https://learn.microsoft.com/en-us/azure/foundry/agents/how-to/tools/bing-tools), read Nov 12, 2026
- [Grounding with Bing Search resource](https://learn.microsoft.com/en-us/answers/questions/2277223/alternatives-to-bing-web-search-in-azure-openai-se), read Nov 12, 2026
- [Bing Web Search response objects](https://learn.microsoft.com/en-us/bing/search-apis/bing-web-search/reference/response-objects), read Nov 12, 2026
- [SerpApi pricing](https://serpapi.com/pricing), read Nov 12, 2026
- [Google Custom Search JSON API overview](https://developers.google.com/custom-search/v1/overview), read Nov 12, 2026
- [SpecStream benchmarks](https://specstream.ai/benchmarks), read Nov 12, 2026
- [SpecStream pricing](https://specstream.ai/pricing), read Nov 12, 2026
- [SpecStream for agents](https://specstream.ai/agents.md), read Nov 12, 2026