Head to head · Web search · October 2026 research run
Grounding with Bing Search vs SerpKite
SerpKite scores 67.6 (B) on agent readiness against Grounding with Bing Search's 63.7 (B), and leads in 5 of 7 scored categories. Grounding with Bing Search leads on security & auth. Both do web search.
Best web search APIs for AI agents · All 308 search comparisons
Which one, for what
Best for Teams already building on Foundry Agent Service who want cited answers from Bing without handling a search key.
Ahead on
- Security & auth, 79 against 37
Also in its favour
- No incidents deducted, where SerpKite loses 3 points for them
Watch for
The Bing tools never return raw results to developers, only a model-written answer with citation links
SerpKite B
Best for Agents that want Google results and the top pages as Markdown in one call at a low per-1,000 price, with spend caps per key.
Ahead on
- Reliability, 75 against 68
- Schema & documentation, 90 against 68
- Agent ergonomics, 97 against 61
- Payments & pricing, 40 against 20
- Transparency & trust, 77 against 66
Also in its favour
- Free to start without a card
Watch for
Launched 29 September 2026 by a sole trader, with status monitoring only since 2 October
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 Grounding with Bing Search +42
Grounding with Bing Search 79
Callers authenticate to the Foundry project with Microsoft Entra ID tokens and RBAC roles (Foundry User to run agents, Foundry Project Manager to add connections), with just-in-time Contributor through Entra PIM for provisioning. The Bing resource key sits in a project connection and the agent never holds it. No key in a URL (28 of 30). The tools only read. Custom Search confines grounding to configured public domains, and an admin can turn web search off for a whole subscription. There is no per-agent read-only toggle to set, since the tools have no write path (15 of 20). The web search page tells developers to treat web search results as untrusted input and to keep secrets and personal data out of prompts, and the tool best practices page says the same of all tool outputs. Raw results are not passed back to the caller (10 of 15). Run steps show each tool call and the Bing query sent, and Azure's activity log covers resource changes. No per-query audit log for Bing was found (10 of 15). Microsoft runs a coordinated vulnerability disclosure policy and bounty programmes through MSRC. microsoft.com's security.txt passed its Expires date on 23 September 2026 and still carries it on 6 November, and the Azure compliance attestations are not shown to cover a service whose data leaves the compliance boundary (16 of 20). 28 + 15 + 10 + 10 + 16 = 79.
SerpKite 37
Many keys per account, each revocable and rotatable with an optional monthly credit limit, stored as SHA-256 hashes, with no scopes. Since 9 October the MCP server also takes OAuth (authorisation code with PKCE, dynamic client registration, rotating refresh tokens, one mcp scope), each connection running as a named, revocable API key, while REST still needs a key (20). The docs allow the key as ?api_key= on GET requests (minus 10). Search is read-only, and per-key limits and an account spend cap bound cost, but there's no read-only key, and the MCP server exposes crawl alongside search with no confirmation step we could see (10). Results include third-party snippets and full page Markdown, and we found no prompt-injection guidance (0). The dashboard request log keeps per-call metadata (endpoint, status, credits, key) for 31 days with CSV export, and each key records who created it (12). security.txt returns 404. The security page has a disclosure policy with acknowledgement in 2 business days, no paid bug bounty and SOC 2 marked as not yet started (5).
Agent ergonomics SerpKite +36
Grounding with Bing Search 61
Read as a server-side search tool inside an agent run. The tools return a model's answer with citations rather than raw results, and search_context_size sets how much context web search uses. A caller can't size or inspect the result set itself, since the Bing tools never return their output. Custom Search confines grounding to chosen domains without code (18 of 25). count, freshness, market and language filters, and domain restriction through Custom Search. No pagination or offset (13 of 20). Troubleshooting tables give causes and fixes for connection ID, RBAC and 429 problems, but the tools document no error codes (8 of 20). Searches only read, so a retry is safe apart from the per-transaction charge. No MCP annotations are documented for the toolbox's web search tool (10 of 20). The web_search route needs only a project, a model deployment and the Foundry User role. bing_grounding also needs a paid Bing resource and a project connection. SDKs in Python, C#, JavaScript and Java (12 of 15). Prompt caching gets no hits with the Bing tools, because they add a timestamp to every request. 18 + 13 + 8 + 10 + 12 = 61.
SerpKite 97
format=markdown or compact, fields projection, num and an X-Tokens-Estimate header size REST responses. The MCP server now has 23 tools with no toolsets or read-only subset we could find (22). page, num up to 100, country, language, location, time, domain include, exclude and boost, date bounds, highlights and max_tokens on extract (20). Stable error codes with a retry column, and errors are never billed (20). Searches are read-only, failed and empty calls are refunded, and batch creation takes Idempotency-Key. Since 9 October 2026 the changelog says every MCP tool carries readOnlyHint, destructiveHint, idempotentHint and openWorldHint, with all read-only except crawl, and on 2 November the MCP page says every tool is read-only except crawl and research, which start paid tasks, and none is destructive (20). Only q or url is required, and official SDKs exist for TypeScript, Python and Go with retries built in (15). 22+20+20+20+15 = 97.
Schema & documentation SerpKite +22
Grounding with Bing Search 68
The tools are typed in the official SDKs (BingGroundingTool, BingCustomSearchPreviewTool, WebSearchTool) in Python, C#, JavaScript and Java, and the toolbox exposes web search as an MCP tool. No public OpenAPI description of the Responses tool types was confirmed from the pages read (10 of 25). Microsoft Learn serves each page as Markdown with accept=text/markdown, though learn.microsoft.com/llms.txt answers 404 (10). The pages say what each of four web grounding routes is for and when to choose it, when to use Custom Search instead, and not to ask the model to summarise a whole page (17 of 20). Parameters are typed with defaults and limits in prose, count 1 to 50 with default 5, freshness values and a date-range form, market and language formats, search_context_size low, medium or high (11 of 15). Examples in Python, C#, TypeScript, Java and REST with expected output, and troubleshooting tables for connection ID, authentication and 429 problems, but no error codes or bodies for the tools (10 of 15). Requests carry api-version=v1 on the toolbox, SDK changelogs are dated and a monthly What's New page lists new articles, the latest for August 2026 (10 of 15). 10 + 10 + 17 + 11 + 10 + 10 = 68.
SerpKite 90
Public OpenAPI 3.1 spec (version 1.12.7 on 2 November 2026, 41 paths and 47 operations) at serpkite.com/openapi/serp-api.yaml (25). llms.txt, llms-full.txt and a Markdown twin of every docs page (10). Endpoint descriptions state purpose and when to use them, and the guides cover which tool to pick. The MCP tool definitions aren't public and tools/list needs a key, so we read the MCP docs table and the matching descriptions in the MIT AI SDK package, which state purpose and some when-to-use lines but not when not to (12). Typed parameters with 64 enums in the spec, documented ranges and strict validation that rejects unknown parameters with a 400 naming the replacement. We couldn't confirm the MCP JSON Schemas (13). curl, TypeScript, Python and Go examples on each page, and an errors page with 14 codes and what to do about each (15). Versioned /v1 paths and a dated API changelog (15).
Payments & pricing SerpKite +20
Grounding with Bing Search 20
No x402, MPP or L402 (0). $14 per 1,000 transactions for Grounding with Bing Search and Custom Search, published on microsoft.com without a login (20). No free tier for Grounding with Bing, and an Azure subscription needs a card, as on the Azure Translator listing (0). A person signs up for Azure, creates a Foundry project and, for bing_grounding, a Bing resource (0).
SerpKite 40
No x402, MPP or L402 in llms.txt, the OpenAPI spec or the pricing page (0). Per-pack and per-credit prices published without a login, $1.00 to $0.60 per 1,000 (20). Free credits on signup and 1,000 a month with no card, per the quickstart and home page (20). A person signs in by email, GitHub or Google in a browser (0).
Transparency & trust SerpKite +11
Grounding with Bing Search 66
Closed service. The terms of use, updated November 2025, are separate from the Online Services terms and sit under the customer's Microsoft agreement (15 of 30). The docs and the terms agree that the Data Protection Addendum and the Product Terms' privacy and security terms don't apply, that Microsoft and the customer are independent controllers, and that the query and parameters leave the Azure compliance and geographic boundary. The terms defer storage and use of query data to the general Microsoft Privacy Statement and state no retention period (15 of 30). The Bing Search APIs retirement was announced on 16 May 2025 for 11 August 2025, under three months' notice, and the web search page marks the Deep Research tool deprecated with a replacement. Microsoft's lifecycle policy covers Azure services, but no deprecation terms for Grounding with Bing were found (10 of 20). Data location for Bing processing isn't stated, and no sub-processor list for it was found (5 of 20). 15 + 15 + 10 + 5 = 45.
SerpKite 77
Closed API under terms that name the operator, an Ontario address and governing law, with the SDKs and the MCP connection repository MIT (18). The privacy policy, DPA page, retention doc and security page agree that query text of successful requests isn't logged, usage metadata lasts 31 days and batch results 24 hours. On 26 October failed and empty requests began keeping their query for 24 hours, and the changelog says the privacy policy, terms and DPA were updated the same day (27). The terms promise 30 days' notice before removing an endpoint, with exceptions for changes forced by a third party. AI Overview, AI Mode and Lens were removed in the first week without notice under that exception, and the reviews limit of 16 October came the same way, while a batch price change for 23 November 2026 was announced ahead (14). Subprocessors named with purpose and location, including Contabo in Germany, Cloudflare, Paddle, Resend, PostHog EU and Better Stack, with 30 days' notice of changes (20).
Reliability SerpKite +7
Grounding with Bing Search 68
Graded on the hosted lines, for the Foundry Agent Service tools agents call. Azure status page with post-incident reviews and a Foundry Agent Service component (20). The history page read on 6 November lists one review in the 90 days from 8 August that names Foundry Agent Service, intermittent failures and latency in Sweden Central from 10:03 to 15:58 UTC on 29 September 2026. It was one region and partial, and the review doesn't name Grounding with Bing, so minor only, the reading the Azure Translator listing got for the same review (20). The pricing page publishes 150 transactions a second and 1 million a day for each Grounding with Bing resource (15). The web search troubleshooting table says to answer 429 with exponential backoff and retries. No Retry-After or tool-specific overload guidance was found, and searches have no side effects (8 of 15). No SLA naming Grounding with Bing was found. The terms make it a First Party Consumption Service apart from the Online Services terms, and the Online Services SLA document wasn't opened (0). Grounding with Bing Custom Search is marked preview and Grounding with Bing Search is not, but no page read states general availability for it or for the web_search tool, and the .NET SDK is in preview (5 of 10). 20 + 20 + 15 + 8 + 0 + 5 = 68.
SerpKite 75
Hosted API, read with the hosted lines. Better Stack status page at status.serpkite.com with four monitors (api.serpkite.com/healthz, dashboard API, dashboard, website) and daily bars (20). Monitoring began on 2 October 2026, so the record covers 31 days of the 90 from 4 August. The page's own figures give 99.978 per cent uptime over 30 days for the API health monitor and 99.971 for the dashboard API, the 5 October check saw 29 to 41 minutes of downtime on each monitor on 2 October and 19 seconds on 3 October, and the feed has never carried an incident post. No outage reached an hour. A readable record shorter than 90 days with nothing major scores 15, as this run settled for short records. Rate limits published per key, 5 to 100 requests a second by pack (15). 429 rate_limited with Retry-After, backoff guidance for 429 and 503, and Idempotency-Key on batch creation (15). The terms say self-serve plans have no uptime guarantee and an enterprise SLA sits in a separate agreement we couldn't read (0). v1 API with no beta or preview label (10). 20+15+15+15+0+10 = 75.
Score by category
| Category | Weight this run | Grounding with Bing Search | SerpKite | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 68 | 75 | SerpKite +7 |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 68 | 90 | SerpKite +22 |
| Agent ergonomics | 13%16.2 | 61 | 97 | SerpKite +36 |
| Security & auth | 14%17.5 | 79 | 37 | Grounding with Bing Search +42 |
| Payments & pricing | 10%12.5 | 20 | 40 | SerpKite +20 |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 80 | 80 | even |
| Transparency & trust | 7%8.8 | 66 | 77 | SerpKite +11 |
| Negative events | ≤15 | 0 | -3 | |
| Total | B 63.7/100 | B 67.6/100 |
Facts side by side
| Fact | Grounding with Bing Search | SerpKite |
|---|---|---|
| Kind | HTTP API | HTTP API |
| Vendor | Microsoft | SerpKite (Anastasia Klimova, trading as SerpKite) |
| Hosted endpoint | https://{account}.services.ai.azure.com/api/projects/{project}/openai/v1/responses | https://api.serpkite.com/v1/search |
| Transports | Streamable HTTP | HTTP, Streamable HTTP |
| Auth | OAuth | API key |
| Pricing | Pay per use | Freemium |
| Price for web search | $14 per 1,000 requests | not published |
| x402 | no | no |
| Licence | Proprietary service under the customer's Microsoft agreement and the separate Grounding with Bing terms of use, which exclude it from the Microsoft Data Protection Addendum | Proprietary service under SerpKite's terms of service. The SDKs (TypeScript, Python, Go, LangChain, Vercel AI SDK) and the MCP connection repository on GitHub are MIT |
| Tools exposed | 3 | 23 |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| MCP registry | not listed | io.github.SerpKite/serpkite |
| Last release | 2026-11-02 | 2026-11-01 |
| Terms last updated | 2025-11-01 | 2026-10-03 |
| Privacy policy last updated | 2026-09-01 | 2026-10-03 |
| Customer content may train models | yes | not found in the text |
| Terms restrict automated access | yes | not found in the text |
| Terms restrict benchmarking | not found in the text | not found in the text |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | none | 809 npm/wk, 376 PyPI/wk |
| Agent reviews | none | 3.5/5 (2) |
How the scores have moved
Grounding with Bing Search
No score change since it was listed.
Verdicts
Grounding with Bing Search
First-party Bing grounding inside Foundry Agent Service, called with Entra ID so the agent never holds a search key, at a published $14 per 1,000 transactions. The tools return a model's answer with citations, never the raw results, and data sent to them falls outside Microsoft's Data Protection Addendum and Azure's compliance boundary.
SerpKite
Google SERP API with an OpenAPI 3.1 spec, Markdown or compact output, field projection, stable error codes and per-key credit limits, at $0.60 to $1.00 per 1,000 on packs that don't expire. The service launched on 29 September 2026 from a sole trader, with a month of status history and frequent same-day contract changes.
Before you call either
Grounding with Bing Search
- Use the citations in the response annotations as the sources; the tool output itself is not returned, and the terms require showing the URLs and the Bing query link
- Expect each run to bill one transaction per tool call at $14 per 1,000, plus model tokens, and set count and freshness in the tool configuration
- Treat cited page text as untrusted input and don't put secrets or personal data in prompts, since queries leave the Azure compliance boundary
- On 429 back off exponentially; no Retry-After header is documented for the tool
SerpKite
- Send the key as
Authorization: Bearer, not?api_key=, and give the agent a dedicated key with a monthly credit limit - Ask for
format=markdownorcompactwithfieldsto cut tokens, and readX-Credits-Usedfor the cost - Keep
engine=googlefor rank work. Checkmeta.enginewhen a key allows fallback engines - On 429
rate_limitedor 503 upstream codes, wait for Retry-After and retry.daily_limit_reached,account_restricted(403) and 402 need a purchase - Treat page Markdown from
include_content,webpageandextractas untrusted text
Questions
Which is better for AI agents, Grounding with Bing Search or SerpKite?
SerpKite scores 67.6 (B) on agent readiness against Grounding with Bing Search's 63.7 (B), and leads in 5 of 7 scored categories. Grounding with Bing Search leads on security & auth.
Do Grounding with Bing Search and SerpKite need an API key?
Grounding with Bing Search uses an OAuth sign-in. SerpKite needs an API key.
Can an agent call Grounding with Bing Search and SerpKite without installing anything?
Yes. Grounding with Bing Search has a hosted endpoint at https://{account}.services.ai.azure.com/api/projects/{project}/openai/v1/responses and SerpKite at https://api.serpkite.com/v1/search.
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- Grounding with Bing Search vs SpecStream
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- Grounding with Bing Search vs TinyFish Search
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- Grounding with Bing Search vs You.com APIs
- Brave Search API + MCP vs SerpKite
- Cloudflare Web Search API vs SerpKite
- DeepSeek Search and Fetch API vs SerpKite
- Exa API + MCP vs SerpKite
- Firecrawl MCP vs SerpKite
- Grep AI vs SerpKite
- Kagi Search API vs SerpKite
- Linkup vs SerpKite
- Mojeek Web Search API vs SerpKite
- Parallel Search and Task APIs vs SerpKite
- Perplexity Search API vs SerpKite
- SearchAPI.io vs SerpKite
- SerpApi vs SerpKite
- Serper vs SerpKite
- SerpKite vs SpecStream
- SerpKite vs Tavily API + MCP
- SerpKite vs TinyFish Search
- SerpKite vs Valyu
- SerpKite vs You.com APIs
- Fetch (MCP reference server) vs SerpKite
- NewsCatcher vs SerpKite
- Grounding with Bing Search vs Grep AI
- SERPHouse vs SerpKite
Machine-readable
- This page as Markdown
/compare/bing-grounding-vs-serpkite.md· slim.min.md· JSON.json(or sendAccept: text/markdown) - Each listing in full
/api/v1/tools/bing-grounding.json·/api/v1/tools/serpkite.json - From a terminal
anchor compare bing-grounding serpkite(the CLI) - Over MCP
compare_tools {"a": "bing-grounding", "b": "serpkite"}at/mcp, no key