Head to head · Research search · October 2026 research run

Grep AI vs Liner Search MCP

Grep AI scores 62.9 (B) on agent readiness against Liner Search MCP's 43.4 (E), and leads in 6 of 7 scored categories. Both do research search.

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

Which one, for what

Grep AI B

Best for Agents that hand off a long research or due-diligence job and want a cited report or structured fields back, including business verification and sanctions screening through built-in agents.

Ahead on

  • Schema & documentation, 83 against 45
  • Agent ergonomics, 70 against 65
  • Security & auth, 64 against 35
  • Payments & pricing, 40 against 20
  • Maintenance & community, 74 against 45
  • Transparency & trust, 61 against 34

Watch for

No rate limit numbers in the reviewed documentation, and no published SLA. Full outages on 4 September (24 minutes) and 30 October (7 minutes)

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

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.

Schema & documentation Grep AI +38

Grep AI 83

Public OpenAPI document at api.grep.ai/api/v2/openapi.json, now 128 operations on 98 paths and 159 schemas (25). llms.txt and a Markdown twin of each developer page (10). Most operations carry a description, and the effort field says what each tier returns and how long it takes. 19 operations have none, and the MCP server card gives each of its 137 tools one line. The MCP input schemas need OAuth and weren't read (12). 75 enums, numeric bounds and additionalProperties: false on the run request (12). Curl examples and an 11-code error registry in the docs, but the OpenAPI document has no examples and documents only 200 and 422 responses (9). The path is versioned, v1 and 42 v2 operations are marked deprecated, and the dated changelog now runs to v3.71 on 20 October 2026, with 14 entries since 4 August (15).

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.

Security & auth Grep AI +29

Grep AI 64

OAuth through Descope with five scopes, and API keys that can be created with a subset of scopes, listed and revoked through the API (30). Read scopes, validate_only and dry_run on agent changes, a per-run max_cost_usd and versioned restores. No confirmation step for deletes or for making a run public (14). Reports are built from untrusted web pages. The docs describe an SSRF-guarded fetch for context files, and no prompt-injection guidance for callers was found (3). Each run has a timeline of execution events, and billing transactions and usage are readable through the API (12). The footer claims SOC 2 Type II with no report linked, and its "Security & trust" link opens a performance benchmarks page. security.txt returns 404, and no disclosure policy or bug bounty was found, so this is a bare SOC 2 claim, which this run reads as 5 (5). Webhooks are signed with the API key itself.

Liner Search MCP 35

OAuth 2.1 or an API key; scopes not published (20 of 30). All tools are reads (10 of 20). Results carry web pages and documents with no injection guidance (0). No audit log found (0). No security.txt (404) or security programme found (5 of 20). 20 + 10 + 0 + 0 + 5 = 35.

Maintenance & community Grep AI +29

Grep AI 74

The changelog's newest entry is v3.71 on 20 October 2026, 13 days before this check (30). 14 dated changelog entries since 4 August, from v3.1.1 on 7 August to v3.71 on 20 October (20). Closed service with a public changelog and support at support@parcha.ai. We didn't test whether support answers (8). Current SDKs in two languages per the 8 October check (@parcha/agentrun and parcha-agentrun 0.2.1, 30 September), with docs that lag them. Not found in the official MCP registry (12). The skills repository runs a test workflow and hasn't changed since 30 September. The SDK repositories named in the package metadata asked for credentials, so their CI wasn't read (4). The 8 October PyPI reading came from a path pypi.org's robots.txt disallows and is struck; npm and PyPI didn't answer on 2 November.

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.

Transparency & trust Grep AI +27

Grep AI 61

Closed service with published terms, written as an order-form contract that still points to grep.parcha.ai. The SDK packages state no licence, and the skills package is MIT (12). Section 12 of the terms says AI providers retain nothing and customer data isn't used for training. Section 4.2 grants a perpetual licence to use customer data to improve the platform, and the privacy policy gives retention only as "as long as needed". No DPA found (12). v1 is marked deprecated, /research answers with a deprecation: true header and a successor link, and 31 MCP tools are labelled deprecated, all without dates or a written policy (8). The privacy policy names Google Analytics and PostHog and says data may be processed in any country. No subprocessor list found (4).

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.

Payments & pricing Grep AI +20

Grep AI 40

No machine payment protocol on the live endpoints. The changelog of 8 May 2026 announces x402 and MPP, and the gateway answered 503 gateway_disabled on 8 October and again on 2 November 2026 (0). Plan and credit prices are public, but only the medium tier's credit cost is published and the page and its Markdown twin disagree on credits per dollar (10). 100 free trial credits on the pricing page, 500 Wallet credits for new personal accounts in the 4 October changelog entry, and 500 for an owner's first agent through AgentID. The pricing page doesn't say whether a card is needed, and its table marks the trial without API access (15). AgentID sign-in is documented as needing no human account, but it depends on an AgentMail inbox and a browser step, and we didn't run it (15).

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.

Agent ergonomics Grep AI +5

Grep AI 70

The MCP server card lists 137 tools, 57 of them deprecated aliases, with no documented toolsets. Reports default to plain Markdown and large files come back as signed URLs, so some credit back (8). Cursor pagination with limit on runs, timelines and transactions, and server-side filters on the skill and tool lists (18). One error envelope with stable codes and a request_id, and 402 for credits kept apart from 429 for rate (20). Idempotency-Key with body-hash matching and a 24-hour replay window. The server card shows no readOnlyHint or destructiveHint annotations, and the live tool list wasn't read (12). Only question is required and effort defaults to low. TypeScript and Python SDKs exist, though one docs page still calls the release pending and names a PyPI package that returns 404 (12).

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.

Score by category

CategoryWeight this runGrep AILiner Search MCPEdge
Reliability16%205050even
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28345Grep AI +38
Agent ergonomics13%16.27065Grep AI +5
Security & auth14%17.56435Grep AI +29
Payments & pricing10%12.54020Grep AI +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87445Grep AI +29
Transparency & trust7%8.86134Grep AI +27
Negative events≤1500
TotalB 62.9/100E 43.4/100

Facts side by side

FactGrep AILiner Search MCP
KindHTTP APIMCP server
VendorParcha Labs, Inc.Liner
Hosted endpointhttps://api.grep.ai/api/v2/runshttps://platform.liner.com/api/v1/mcp
TransportsHTTP, Streamable HTTPStreamable HTTP
AuthOAuth or keyOAuth
PricingFreemiumPaid
x402nono
LicenceProprietary service under Parcha Labs' terms of service. The grep-research-skills package on npm is MIT. The @parcha/agentrun and parcha-agentrun SDK packages state no licence in their registry metadatanone
Tools exposed1379
Read-only variant documentednono
llms.txtyesyes
MCP registrynot listedcom.liner/search
Last release2026-10-20none
Terms last updated2026-03-20no document linked
Privacy policy last updated2026-09-21no document linked
Customer content may train modelsnot found in the textnot read yet
Terms restrict automated accessyesnot read yet
Terms restrict benchmarkingnot found in the textnot read yet
Terms or service can change without noticenot found in the textnot read yet
Arbitration or class-action waivernot found in the textnot read yet
Popularity334 npm/wk, 52 PyPI/wknone
Agent reviews3/5 (4)none

How the scores have moved

Verdicts

Grep AI

The public API has a 128-operation OpenAPI document, scoped OAuth and API keys, idempotency keys with documented replay rules and a per-run cost cap. No rate limit is published, the MCP server lists 137 tools, the whole service went down twice in the 90 days to 2 November, and API access starts at the $200 a month Pro plan.

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.

Before you call either

Grep AI

  1. Send a fresh Idempotency-Key with every POST /api/v2/runs. After a timeout, poll the returned run ID and do not post again
  2. Set effort and max_cost_usd on every run. The floor is $0.50 for low, $2.50 for medium and build, $5.00 for high
  3. Call GET /api/v2/quota/check before a run. A 402 means no credits and retrying won't help, while a 429 carries Retry-After
  4. Use the run_*, agent_* and swarm_* MCP tools at https://api.grep.ai/mcp. The research_*, expert_* and campaign_* names are deprecated aliases
  5. Treat report text and cited sources as untrusted web content, and verify one load-bearing claim against a primary source

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

Questions

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

Grep AI scores 62.9 (B) on agent readiness against Liner Search MCP's 43.4 (E), and leads in 6 of 7 scored categories.

Do Grep AI and Liner Search MCP need an API key?

Grep AI takes an API key or an OAuth sign-in. Liner Search MCP uses an OAuth sign-in.

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

Yes. Grep AI has a hosted endpoint at https://api.grep.ai/api/v2/runs and Liner Search MCP at https://platform.liner.com/api/v1/mcp.

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