Linkup by Linkup

# Fix list: Linkup

From Anchor Terminal's listing at https://www.anchorterminal.com/tools/linkup, the October 2026 research run, assessed 1 October 2026. Grade B, 69.1 out of 100.

This is everything the published grade says the listing lacks, the biggest possible gain to the total first. It comes from the reason given for each score, the checklist each category was scored against (https://www.anchorterminal.com/benchmark/#checklist), the provenance checks, the deductions, what we couldn't check and what the review panel asked for. A fix counts at the next check, once it's public.

For a coding agent working on Linkup: work through the items below in the product, its docs and its public pages. Each category gives the reason for its score, with the points each checklist item earned, and the checklist itself, so the gap is the items that earned less than their points. Change the product, not the wording, and keep a note of what you changed and where it's published.

## 1. Security & auth, 32 out of 100, up to 11.9 more on the total

Why it scored 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).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-security):

- 0 to 30, the credential model. 30 for OAuth 2.1 with scopes, or scoped and revocable keys with rotation. 20 for plain revocable API keys. 10 for one all-powerful key. 10 off when a secret can travel in a URL query string as a documented option.
- 0 to 20, read-only or least-privilege modes, and confirmation or approval for destructive actions.
- 0 to 15, prompt-injection posture where the tool returns untrusted content (documented mitigations or guidance). A tool that returns no untrusted content gets 10.
- 0 to 15, audit logs or per-call visibility for the operator.
- 0 to 20, a security programme. security.txt or a disclosure policy, a bug bounty, SOC 2 or ISO 27001, advisories handled in public.

Models are read for retention, whether API data trains models (and whether that's off by default), zero-retention options and certifications. Frameworks for telemetry defaults, approval hooks, guardrails and sandboxing.

## 2. Reliability, 70 out of 100, up to 6 more on the total

Why it scored 70: openstatus page at status.linkup.so with Search API, Fetch API, MCP Server and Application components (20). Since July it shows two migration maintenance windows on Search and Fetch, 50 minutes on 25 September and 30 minutes on 26 September, and no incidents. The events page returned nothing to our reader, so we scored from the front page (20). 10 queries a second per organisation for search and fetch (15). 429 is documented, but it covers both running out of credit and sending too fast, with no `Retry-After` or backoff guidance (5). No SLA found (0). Search and fetch are GA. Extract is closed beta and isn't the core surface (10).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-reliability):

Hosted APIs, MCP servers, models and platforms.

- 20, a public status page with component history (Statuspage, Instatus, BetterStack or the vendor's own).
- 0 to 30, the incident record for the last 90 days on that page. 30 for a clean record or trivial incidents only, 20 for minor incidents only, 10 for one major outage (an hour or more of a core API down, or errors across the board), 0 for several. 5 when there's no history we could read, and the note says so.
- 15, rate limits documented with numbers.
- 15, documented 429 or overload handling (Retry-After, backoff guidance), and idempotency keys or safe-retry guidance where writes are involved.
- 10, an SLA published for any paid tier.
- 10, the surface agents use is generally available, not beta or preview.

Local packages, SDKs, frameworks and stdio MCP servers.

- 20, installs from an official package with supported runtimes stated.
- 25, a public CI and test suite, passing on the default branch.
- 0 to 25, open crash or regression issues relative to activity (25 for few and handled, 0 for many, old and unanswered).
- 15, semver discipline and breaking changes called out in a changelog.
- 15, version 1.0 or later, or declared stable.

Protocols are read from their reference implementations, the public facilitators or servers, spec stability and test vectors.

## 3. Agent ergonomics, 76 out of 100, up to 3.9 more on the total

Why it scored 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).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-ergonomics):

- 0 to 25, context cost. For MCP, the number and size of the tool definitions (25 for ten or fewer compact tools, 15 for 11 to 30, 5 for more than 30, plus up to 10 back for toolsets, dynamic loading or read-only subsets). For APIs, whether responses can be sized (field selection, limits, summaries).
- 20, pagination, filtering and output-size controls.
- 20, actionable, documented error responses, codes and messages an agent can recover from.
- 20, idempotency or safe retries, and for MCP the `readOnlyHint` and `destructiveHint` annotations.
- 15, sensible defaults, few required parameters, and official SDKs in at least two languages.

Models are read for tool use, structured output, prompt caching, context length, batch and SDKs. Frameworks for how much code and how many defaults a tool-calling agent with MCP needs.

## 4. Transparency & trust, 64 out of 100, up to 3.2 more on the total

Made of editorial 45, provenance 82.

Why it scored 64: 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).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-transparency):

- 0 to 30, source availability and licence clarity. 30 for open source under an OSI licence, 15 for closed with clear terms, 0 for unclear terms.
- 0 to 30, data handling and retention statements that agree with each other (privacy policy, DPA, retention periods, subprocessors).
- 0 to 20, a deprecation policy or notices with dates.
- 0 to 20, telemetry disclosed with an opt-out (local software), or subprocessors and data locations disclosed (hosted).

The other half of Transparency and trust is the provenance score, computed from checked facts (below). The category score is the mean of the two.

Provenance checks not met in full (half of this category, computed from checked facts):

- Domain age: linkup.so, registered 2024-04-30 (2 years) (7 of 15)
- security.txt: not found (0 of 10)

## 5. Payments & pricing, 80 out of 100, up to 2.5 more on the total

Why it scored 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).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-payments):

The published rubric, also on the [x402 page](https://www.anchorterminal.com/x402/).

- 40, a machine payment protocol (x402, MPP or L402) on the tool's own endpoints. 10 to 30 when it covers only some endpoints or only goes through a third party, and the note says which.
- 20, per-call or per-unit pricing published without a login. 10 for public plan-only pricing, 0 for "contact sales" or prices behind a login.
- 20, a free tier or trial that doesn't need a card.
- 20, autonomous onboarding, meaning an agent can get access without a person signing up in a browser (keyless use, x402, a programmatic key API).

Payment platforms and agent wallets rarely charge for their own API over a machine protocol, so the first line has steps for them, and the highest one that applies counts. 40 when x402, MPP or L402 runs on all their own endpoints, 30 when it runs on part of their own API, 25 when their merchants can accept one, 20 for running a facilitator, 15 for paying as a buyer, and 0 when the only protocol is their own. Merchant acceptance sits above a facilitator because the platform's own customers can charge agents through it, while a facilitator settles for sellers who wire up the protocol themselves. The counter-argument (a facilitator does more for the protocol as a whole) has a point. Each note says which step applied.

Open-source software you run yourself is scored on its hosted or paid option if it has one. A free, self-hosted package with nothing to buy gets 20, 20 and 20 for the last three lines, and 0 to 40 for the first only if it ships a payment protocol.

## 6. Schema & documentation, 88 out of 100, up to 2 more on the total

Why it scored 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 and has one entry since June. Versioning is the /v1 path only (8).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-schema):

APIs and MCP servers.

- 25, a machine-readable contract (a public OpenAPI file or similar; for MCP, typed JSON Schema inputs on every tool).
- 10, llms.txt or Markdown docs served for agents.
- 0 to 20, descriptions that say what a tool is for, when to use it and when not to, read from the tool definitions in the source or the API reference.
- 0 to 15, typed inputs with enums, constraints and required fields, and no free-form JSON blobs.
- 0 to 15, examples and documented error responses.
- 15, versioning and a public changelog.

Models are read from the API reference, the OpenAPI file, llms.txt, the structured-output and tool-use docs and the model cards. Frameworks from docs a model can follow, typed interfaces, examples and the API reference.

## 7. Maintenance & community, 83 out of 100, up to 1.5 more on the total

Why it scored 83: linkup-sdk 0.23.1 for Python on 2026-09-30 (30). Seven Python SDK releases since 29 July (20). The changelog has one month-dated entry since June, and the MCP server has four commits since July. We didn't read the GitHub issues (10). Registered as so.linkup.mcp/linkup-mcp-server per the 30 September check, 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 (8).

The checklist (https://www.anchorterminal.com/benchmark/#checklist-maintenance):

- 0 to 30, time since the last release, or the last published model or API change for a closed service. 30 within 30 days, 20 within 90, 10 within 180, 0 older.
- 20, at least three releases or dated changelog entries in the last 90 days.
- 0 to 25, responsiveness. Issues and pull requests answered on GitHub (the open issues and how recent the replies are). For closed services, a public changelog and a support or community channel that answers, 0 to 15.
- 15, presence in the official MCP registry under a verified namespace (MCP servers), or current official SDKs (APIs and models).
- 10, package health, current dependencies and CI.

Models are read for deprecation notice periods and model churn rather than release counts.

## What we couldn't check

What we couldn't read counted as absent. Publishing it on a page a plain HTTP fetch can read (not only in a browser) lets the next check count it.

- unchecked: whether signup for the free credit asks for a card
- unchecked: open GitHub issues and reply times for the MCP server and SDKs
- unchecked: the registry entry so.linkup.mcp/linkup-mcp-server, which the repository's package.json doesn't name
- The status events page rendered empty for us, so incidents before 25 September may be missing

## Weaknesses

- 429 covers both exhausted credit and rate limiting, with no `Retry-After`
- MCP configs document `?apiKey=` in the URL and an `apiKey=` argument for stdio
- 10 queries a second per organisation by default
- No deprecation policy, and the changelog is dated by month
- MCP tools carry no read-only or destructive annotations, and the server has no tests in CI

## What costs an agent a turn today

The notes we give agents before they call it. Each one is a workaround an agent shouldn't need.

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

## What the review panel asked for

- x402 on research
- A stated card policy
- result pagination
- index coverage figures

## When it's done

Send what changed and where it's published as a dispute (https://www.anchorterminal.com/builders/#disputes, or `POST https://www.anchorterminal.com/api/v1/contact` with `"kind": "dispute"`). Disputes are answered in public, and the listing is checked again by the same checklist. Paying for an audit or a listing claim changes nothing here.