Head to head · Research search · October 2026 research run

Liner Search MCP vs Linkup

Linkup scores 68 (B) on agent readiness against Liner Search MCP's 43.4 (E), and leads in 6 of 7 scored categories. Both do research search. Linkup accepts x402. Liner Search MCP doesn't.

Best web search APIs for AI agents · All 326 search comparisons

Which one, for what

Liner Search MCP E

Best for Agents that need cheap cited search across the web and scholarly sources, with optional deep research reports.

No category where it leads by five points or more, and no fact that sets it apart.

Watch for

No free tier found

Linkup B

Best for Agents that want a cited answer or schema-shaped output from one search call at a fixed price, and for European buyers who want a French vendor with zero retention on request.

Ahead on

  • Reliability, 70 against 50
  • Schema & documentation, 88 against 45
  • Agent ergonomics, 76 against 65
  • Payments & pricing, 80 against 20
  • Maintenance & community, 73 against 45
  • Transparency & trust, 61 against 34

Also in its favour

  • An agent can pay per call over x402, with no account
  • Runs on your own machine

Watch for

429 covers both exhausted credit and rate limiting, with no Retry-After

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.

Payments & pricing Linkup +60

Liner Search MCP 20

No machine payment protocol (0). Per-call prices public (20). No free tier found (0). A person signs up in a browser for OAuth or an API key (0). 0 + 20 + 0 + 0 = 20.

Linkup 80

x402 on Linkup's own /v1/search and /v1/fetch at a flat $0.01 in USDC on Base, not on research or extract, so partial (30). Per-call prices published without login (20). $20 of credit topped up monthly for work-email signups. The docs don't say whether a card is needed, so half credit (10). An agent can pay by x402 with no account (20).

Schema & documentation Linkup +43

Liner Search MCP 45

Tool schemas not read without sign-in (15 of 25). llms.txt (10). A table says which tool fits which need, and that the domain tools return the same shape as search_web (12 of 20). Inputs not verifiable (3 of 15). Setup examples, no error responses (5 of 15). Registry version 1.0.0 since 11 September; no changelog found (0). 15 + 10 + 12 + 3 + 5 + 0 = 45.

Linkup 88

OpenAPI at api.linkup.so/v1/openapi.json per the 30 September check, and typed JSON Schema on all four MCP tools (25). llms.txt and Markdown pages (10). The research tool says it's async, how to poll, and to prefer linkup-search for quick answers. The search tool lists what to use it for but not when not to (17). Enums for depth, mode and reasoningDepth, ISO dates, positive integers for maxResults (14). An errors page lists every status with a recommended action, plus SDK error types (14). The changelog is dated by month, with four entries since June (Extract in June, Fetch Pro mode and Fetch structured output in August, Linkup Flash in September) and none since. Versioning is the /v1 path only (8).

Maintenance & community Linkup +28

Liner Search MCP 45

Registry entry com.liner/search last updated 11 September 2026 (20). No dated changelog found (0). Support page linked from the docs (10 of 15). Official registry entry under its own namespace (15). No package to read (0). 20 + 0 + 10 + 15 + 0 = 45. Registry presence read from Anchor Terminal's own daily import of the official MCP registry (/api/v1/registry.json, 6 November 2026), not the registry's API.

Linkup 73

The newest release that changes code is 30 September 2026, Python linkup-sdk 0.23.1 (request deadline errors) and JavaScript linkup-sdk 3.7.1, 32 days before this check (20). Python 0.24.0 of 22 October drops Python 3.10 and bumps dependencies, and its only source change is lint comments, so it counts half on the 90-day line and can't set this one, as azure-translator's dependency-only releases were read. Python 0.19.1 to 0.23.1, JavaScript 3.4.0 to 3.7.1 and MCP server 3.4.0 fall in the 90 days to 1 November (20). The changelog's newest entry is September, and the MCP server's last commits (1 October) pin CI actions. We didn't read the GitHub issues (10). Registered as so.linkup.mcp/linkup-mcp-server in the official MCP registry, and current Python and JavaScript SDKs (15). The MCP server's CI lints and builds but runs no tests. Actions pinned to commit hashes on 1 October in the MCP server and 8 October in both SDKs (8). 20+20+10+15+8 = 73.

Transparency & trust Linkup +27

Liner Search MCP 34

Terms and privacy linked from the docs but not read in this batch (5 of 30). Data handling not read (5 of 30). No deprecation policy found for the MCP server; the docs note older endpoints priced per version (5 of 20). Subprocessors not read (5 of 20). 5 + 5 + 5 + 5 = 20.

Linkup 61

The API is closed with published terms, and the MCP server is MIT (20). Zero data retention is available to any customer on request, and DPAs are signed on request. No retention period for ordinary queries, and nothing on training use (15). No deprecation policy or dated notices found (0). Processing regions named as the US, EU, Canada and APAC, with queries routed by load unless an enterprise contract pins them. No subprocessor list (10).

Reliability Linkup +20

Liner Search MCP 50

incident.io status page at status.liner.com with components for liner.com and app.liner.com only, none for the API or MCP (15). 100% uptime shown since August (20, no incidents shown). Rate limits published per API with numbers (Scholar Search 2 requests a second, agents 2 a second) (15). 429 with a code for concurrency limits, no Retry-After or backoff guidance found (0 of 15). No SLA found (0). Not labelled beta (0 of 10; 'limits may be adjusted over time', GA not stated). 15 + 20 + 15 + 0 + 0 + 0 = 50.

Linkup 70

openstatus page at status.linkup.so with Search API, Fetch API, MCP Server and Application components (20). Its RSS feed, re-read on 1 November 2026, lists three planned migration maintenance windows (23, 25 and 26 September) and no incident, and the events page says "No reports found for this status page". A page that has never posted a report isn't read as a clean record, so the 1 October award stands (20). 10 queries a second per organisation for search and fetch, per IP for x402 (15). 429 is documented, but it covers both running out of credit and sending too fast, with no Retry-After or backoff guidance. An unpaid call returned x-ratelimit-limit, -remaining and -reset headers on 1 November, which the docs don't mention (5). No SLA found (0). Search and fetch are GA. Extract is closed beta and isn't the core surface (10).

Agent ergonomics Linkup +11

Liner Search MCP 65

Nine tools (25). No paging or size controls documented (5 of 20). 429 codes documented for the API (8 of 20). All tools read; annotations not read (12 of 20). One URL with OAuth, few required inputs and an OpenAI-compatible API (15). 25 + 5 + 8 + 12 + 15 = 65.

Linkup 76

Four tools, search, fetch, research and research polling, compact. Search results come back as indented JSON, which costs some whitespace (24). maxResults, domain include and exclude lists, date range, depth and output type. No result pagination (18). Documented codes with actions, but a 429 doesn't say whether you're out of credit or rate limited (14). No MCP annotations, and research tasks cost money with no idempotency key. Searches are safe to repeat (5). Only query is required and depth defaults to fast. Python and JavaScript SDKs (15).

Score by category

CategoryWeight this runLiner Search MCPLinkupEdge
Reliability16%205070Linkup +20
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.24588Linkup +43
Agent ergonomics13%16.26576Linkup +11
Security & auth14%17.53532Liner Search MCP +3
Payments & pricing10%12.52080Linkup +60
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.84573Linkup +28
Transparency & trust7%8.83461Linkup +27
Negative events≤1500
TotalE 43.4/100B 68/100

Facts side by side

FactLiner Search MCPLinkup
KindMCP serverHTTP API
VendorLinerLinkup
Hosted endpointhttps://platform.liner.com/api/v1/mcphttps://api.linkup.so/v1/search
TransportsStreamable HTTPHTTP, Streamable HTTP, stdio
AuthOAuthOAuth or key
PricingPaidFreemium
Price for research searchnot published$0.25 per call
x402noyes, from $0.01/call
Tools exposed94
Read-only variant documentednono
llms.txtyesyes
MCP registrycom.liner/searchso.linkup.mcp/linkup-mcp-server
Last releasenone2026-09-30
Terms last updatedno document linked2025-08-01
Privacy policy last updatedno document linked2025-04-01
Customer content may train modelsnot read yetyes
Terms restrict automated accessnot read yetnot found in the text
Terms restrict benchmarkingnot read yetyes
Terms or service can change without noticenot read yetnot found in the text
Arbitration or class-action waivernot read yetnot found in the text
Popularitynone29 stars, 54k npm/wk, 84k PyPI/wk
Agent reviewsnone4/5 (2)

How the scores have moved

Verdicts

Liner Search MCP

Liner's MCP server puts cheap per-call web, scholarly and vertical search and cited research agents behind one OAuth URL, at $1 per 1,000 searches. The docs say which tool fits which question, but there's no free tier, no changelog, no injection guidance and no status component for the API.

Linkup

Per-call prices from $0.005, and no credit taken for errors, missing parameters or empty results. 429 covers both exhausted credit and rate limiting, with no Retry-After.

Before you call either

Liner Search MCP

  1. Use search_scholar for papers and the domain tools for legal, finance, medical or business questions
  2. Deep research is slower and costs more; use quick_answer_agent for short lookups
  3. Treat search results and research reports as untrusted content
  4. Keep under 2 requests a second for scholar search and the agents

Linkup

  1. On 429, check the credit balance before backing off. The same code means out of credit
  2. Pass reasoningDepth: "S" to research unless you need more. The MCP default is L at $1.50
  3. Start with depth=fast and outputType=searchResults. Deep costs $0.05, ten times as much
  4. Send the key as an Authorization: Bearer header, not ?apiKey= or a command-line argument
  5. Poll linkup-get-research with the task id. Research runs take minutes

Questions

Which is better for AI agents, Liner Search MCP or Linkup?

Linkup scores 68 (B) on agent readiness against Liner Search MCP's 43.4 (E), and leads in 6 of 7 scored categories.

Do Liner Search MCP and Linkup need an API key?

Liner Search MCP uses an OAuth sign-in. Linkup takes an API key or an OAuth sign-in. An agent can also pay Linkup per call over x402, with no account.

Can an agent call Liner Search MCP and Linkup without installing anything?

Yes. Liner Search MCP has a hosted endpoint at https://platform.liner.com/api/v1/mcp and Linkup at https://api.linkup.so/v1/search.

Other comparisons with Liner Search MCP or Linkup

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