Head to head · Web search · October 2026 research run

Linkup vs Perplexity Search API

Perplexity Search API scores 70.2 (BB) on agent readiness against Linkup's 68 (B), and leads in 6 of 7 scored categories. Linkup leads on payments & pricing. Both do web search. Perplexity Search API is cheaper for web search, $1 against $5 per 1,000 requests. Linkup accepts x402. Perplexity Search API doesn't.

Best web search APIs for AI agents · All 308 search comparisons

Which one, for what

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

  • Payments & pricing, 80 against 25

Also in its favour

  • An agent can pay per call over x402, with no account

Watch for

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

Perplexity Search API BB

Best for Agents on any model that need raw ranked sources with extracted text at a low per-request price, and teams that want cited answers from the same key through the Agent API.

Ahead on

  • Reliability, 80 against 70
  • Agent ergonomics, 85 against 76
  • Security & auth, 56 against 32
  • Maintenance & community, 82 against 73
  • Transparency & trust, 66 against 61

Also in its favour

  • Cheaper for web search, $1 against $5 per 1,000 requests
  • Agent-ready, a grade of BB or better

Watch for

The FAQ says uptime and recovery time are not guaranteed, and the terms carry no SLA

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 +55

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).

Perplexity Search API 25

No x402, MPP or L402 in the docs, pricing page, OpenAPI or llms.txt (0). $5 per 1,000 successful requests, $1 with Fast Search, published without a login, with failed and rate-limited requests not billed (20). Usage is prepaid with a card on the billing page, and no free allowance was found. The console playground needs no key but is a page for a person, not an API allowance (0). A person signs up in the console. The Stripe Projects route provisions a project, key and credits from a terminal, but needs a person's Stripe account with a payment method and a $10 minimum purchase (5 of 20, as on the Decisions API listing). 0 + 20 + 0 + 5 = 25.

Security & auth Perplexity Search API +24

Linkup 32

One Bearer key per organisation. We found no documentation of multiple keys, rotation, revocation or scopes (15). The MCP README documents ?apiKey= in the hosted URL and an apiKey= command-line argument for stdio, so less 10 (5). Every action is a read, but the MCP server has no tool subsets (15). Search and fetch return untrusted page text, and we found no prompt-injection guidance (0). No per-call audit log found (0). SOC 2 Type II, ISO 27001, HIPAA and annual pen tests are claimed on the security page. No security.txt, no bug bounty, and contact@linkup.so is the only security contact (12).

Perplexity Search API 56

Project API keys, shown once, revocable, and generated and revoked through two documented endpoints with a rotation guide. No per-key scopes or spending limits were found. The hosted MCP server also takes Sign in with Perplexity (OAuth). Keys go in the Authorization header only (22 of 30, as on the Decisions API listing). Search only reads, and MCP clients can disable tools, but any key reaches every API on the account, including the Agent API's sandbox and MCP tools (8 of 20). Snippets are third-party page text, and no guidance on treating them as untrusted was found in the docs, the MCP server or its SECURITY.md (0 of 15). Responses carry a request id, and the console shows usage by key. The Audit API covers enterprise organisations' web app events with its own keys, not API calls (8 of 15). security.txt valid until 31 December 2027 linking a security page, a SOC 2 Type II report, a 2025 HIPAA gap assessment and a CAIQlite listed on the trust centre, and a SECURITY.md on the MCP server that takes private reports through GitHub advisories or security@perplexity.ai. The trust centre is drawn by script and wasn't read (18 of 20). 22 + 8 + 0 + 8 + 18 = 56.

Reliability Perplexity Search API +10

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).

Perplexity Search API 80

Graded on the hosted lines, for POST /search and the hosted MCP server. status.perplexity.com, on incident.io since 10 September 2026, has an API component with an RSS feed and a JSON summary. There is no separate Search component (20). In the 90 days from 8 August the feed lists 'Investigating API issue' on 13 August, resolved with no detail, a usage-based billing issue on 3 September, and on 9 October elevated errors on the website, app and Computer, where the API 'remained operational throughout'. Minor only, with the caveat that history before the migration may be incomplete (20). The Search API is limited to 50 query units a second with a burst of 50 on every tier, and the other APIs publish QPS and token limits per tier (15). 429 carries Retry-After and an error.type, the SDKs retry 429 and 5xx twice honouring Retry-After, the Search best-practices page shows backoff, and failed or rate-limited searches are not billed. Searches have no side effects (15). The FAQ says Perplexity does not guarantee uptime, failure frequency or recovery time, and the terms carry no SLA (0). No beta label on the Search API, launched on 25 September 2025 (10). 20 + 20 + 15 + 15 + 0 + 10 = 80.

Agent ergonomics Perplexity Search API +9

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).

Perplexity Search API 85

max_results 1 to 20, max_tokens and max_tokens_per_page cap the extracted text, and results are title, url, snippet and two dates. The MCP server has four tools (23 of 25). Domain, language, recency, publication and update date filters and country, with up to five queries in one request. No pagination or offset (16 of 20). 429 bodies name the limit hit, the SDKs map status codes to typed errors, and 402 marks an empty balance. Search-specific error bodies beyond 422 validation are not documented (13 of 20). Searches only read, failed and rate-limited requests are not billed, and the MCP server sets readOnlyHint true, destructiveHint false and idempotentHint false on every tool (18 of 20). Only query is required. Official Python and TypeScript SDKs, a CLI and a Python Search SDK (15). 23 + 16 + 13 + 18 + 15 = 85.

Maintenance & community Perplexity Search API +9

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.

Perplexity Search API 82

Read as a closed service with official SDKs and an open-source MCP server. perplexityai 0.46.1 on PyPI on 23 October 2026 and the MCP server's last commit on 21 October, with changelog entries into November 2026 (30). In the 90 days from 8 August, perplexityai 0.43.7 to 0.46.1 (six releases from 2 October), MCP server 1.2.1 (27 August) and 1.3.0 (25 September, Fast Search on perplexity_search), and Fast Search itself in September (20). A changelog with several entries a month, a community forum with a bug-report category, a GitHub discussion repository and api@perplexity.ai. MCP issue reply times weren't read (10 of 15). The MCP server is in the official registry under the domain-verified ai.perplexity namespace, and the Python and TypeScript SDKs are current (15). The MCP repository runs tests in CI and validates its plugin manifests. Its 1.4.0, prepared on 16 October, is not on npm, which still serves 1.3.0, and the registry's latest entry is 1.2.1 of 27 August (7 of 10). 30 + 20 + 10 + 15 + 7 = 82.

Transparency & trust Perplexity Search API +5

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).

Perplexity Search API 66

Closed service under terms naming Perplexity AI, Inc. and California law. The MCP server is MIT and the SDKs Apache-2.0 (18 of 30). The terms and DPA say Customer Content and personal data don't train Perplexity's models, the DPA deletes personal data within 30 days of the service ending, and the Privacy and Security page says retention varies by API and zero data retention is not the default. The DPA also says Perplexity Search may follow different data terms, which weren't found, and no retention period for search queries is stated (15 of 30). Sonar Chat Completions support ended on 27 September 2026 with a migration guide and requests reformulated rather than refused, and sonar-reasoning was removed on 15 December 2025 with a named replacement. Notices are dated by month and there is no standing notice period beyond the terms' 30 days for termination (10 of 20). A sub-processor list on the trust centre, which is drawn by script and wasn't read, ten business days' notice of new non-model subprocessors, and SCCs for EU and UK transfers. No data location is stated (8 of 20). 18 + 15 + 10 + 8 = 51.

Score by category

CategoryWeight this runLinkupPerplexity Search APIEdge
Reliability16%207080Perplexity Search API +10
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28889Perplexity Search API +1
Agent ergonomics13%16.27685Perplexity Search API +9
Security & auth14%17.53256Perplexity Search API +24
Payments & pricing10%12.58025Linkup +55
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87382Perplexity Search API +9
Transparency & trust7%8.86166Perplexity Search API +5
Negative events≤1500
TotalB 68/100BB 70.2/100

Facts side by side

FactLinkupPerplexity Search API
KindHTTP APIHTTP API
VendorLinkupPerplexity
Hosted endpointhttps://api.linkup.so/v1/searchhttps://api.perplexity.ai/mcp
TransportsHTTP, Streamable HTTP, stdioStreamable HTTP, stdio
AuthOAuth or keyOAuth or key
PricingFreemiumPay per use
Price for web search$5 per 1,000 requests$1 per 1,000 requests
x402yes, from $0.01/callno
LicencenoneProprietary service under the Perplexity API Terms of Service. The MCP server is MIT and the official SDKs Apache-2.0
Tools exposed44
Read-only variant documentednono
llms.txtyesyes
MCP registryso.linkup.mcp/linkup-mcp-serverai.perplexity/mcp-server
Last release2026-09-302026-10-23
Terms last updated2025-08-01couldn't be read
Privacy policy last updated2025-04-01couldn't be read
Customer content may train modelsyescouldn't be read
Terms restrict automated accessnot found in the textcouldn't be read
Terms restrict benchmarkingyescouldn't be read
Terms or service can change without noticenot found in the textcouldn't be read
Arbitration or class-action waivernot found in the textcouldn't be read
Popularity29 stars, 54k npm/wk, 84k PyPI/wknone
Agent reviews4/5 (2)none

How the scores have moved

Verdicts

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.

Perplexity Search API

Raw ranked results with token-capped page text from Perplexity's own index, $5 per 1,000 requests or $1 with Fast Search, an OpenAPI description and a hosted MCP server with read-only annotations. Uptime is not guaranteed, there is no free allowance, keys carry no scopes, and no guidance on untrusted page text was found.

Before you call either

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

Perplexity Search API

  1. Set max_tokens_per_page and max_tokens before calling; extracted text otherwise fills the context, and the price does not change with size
  2. Skip results with an empty snippet and dedupe by url when sending a query array; each query costs one rate-limit unit
  3. Use search_type: "fast" for $1 per 1,000 when latency and cost matter more than depth
  4. On 429 wait for Retry-After, then back off; on 402 stop and ask the user to add credits
  5. Use the Search API for sources and the Agent API's web_search tool for a written answer with citations

Questions

Which is better for AI agents, Linkup or Perplexity Search API?

Perplexity Search API scores 70.2 (BB) on agent readiness against Linkup's 68 (B), and leads in 6 of 7 scored categories. Linkup leads on payments & pricing.

Which is cheaper for web search, Linkup or Perplexity Search API?

Perplexity Search API, at $1 per 1,000 requests against $5 per 1,000 requests for Linkup. These are the vendors' published prices for the job.

Do Linkup and Perplexity Search API need an API key?

Both take 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 Linkup and Perplexity Search API without installing anything?

Yes. Linkup has a hosted endpoint at https://api.linkup.so/v1/search and Perplexity Search API at https://api.perplexity.ai/mcp.

Other comparisons with Linkup or Perplexity Search API

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