LinkedIn Marketing APIs

# Fix list: LinkedIn Marketing APIs

From Anchor Terminal's listing at https://www.anchorterminal.com/tools/linkedin-marketing-api, the October 2026 research run, assessed 8 October 2026. Grade B, 62.4 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 LinkedIn Marketing APIs: 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. Payments & pricing, 30 out of 100, up to 8.8 more on the total

Why it scored 30: No x402, MPP or L402 (0). No fee for API access appears in the docs, the API terms or the Marketing API terms, and no page states a price or says the API is free. Ad spend is set by campaign budgets and billed to the ad account (10). A developer application costs nothing and a test ad account needs no card or payment details (20). A person has to create a LinkedIn Page and a developer application, apply for the product and give OAuth consent in a browser (0).

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.

## 2. Reliability, 66 out of 100, up to 6.8 more on the total

Why it scored 66: Read with the hosted rubric, grading the public REST API. Statuspage at linkedin-apistatus.com with incident history back to 2023, covering every LinkedIn API and listing no components (15). No incident since 18 June 2026, so the 90 days to 8 October are clean. The last major entry was API server timeouts for about seven hours on 20 May 2026 (30). The rate-limit page says standard limits are not published and are shown per endpoint in the Developer Portal after a first call. Published numbers are 45 million metric values per 5 minutes and 15,000 elements a response on adAnalytics (6). 429 is documented, 503 and 504 carry advice to retry, and no Retry-After header, backoff schedule or idempotency key was found (5). No SLA found, and the API terms supply the service as is (0). The Advertising API is generally available on version 202609 (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, 63 out of 100, up to 6 more on the total

Why it scored 63: Field projections with `fields=` and a `fields` list on adAnalytics size responses (20). Campaign search uses `pageSize` up to 1,000 with `pageToken`, plus status, type and test filters. adAnalytics stops at 15,000 elements (18). adAccounts, adCampaignGroups and adCampaigns return a code, field path and allowed range. Other endpoints return message, serviceErrorCode and status only (14). No idempotency key found. DRAFT status, a test ad account and `versionTag` reduce the cost of a wrong write, and Conversions API events are deduplicated by event ID (6). Every call needs two extra headers and Rest.li query encoding, and the official Python and JavaScript clients are beta, last released in 2023 (5).

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. Security & auth, 66 out of 100, up to 6 more on the total

Why it scored 66: Three-legged OAuth 2.0 only, with scopes per product such as r_ads, r_ads_reporting, rw_ads, rw_dmp_segments and rw_conversions. Access tokens last 60 days, refresh tokens 365, a member can revoke them, and a token introspection endpoint exists. The docs tell developers not to pass tokens in URLs (26). Read scopes are separate from rw_ads, the VIEWER role is read-only even with rw_ads, and Development tier limits edits to five ad accounts. No confirmation step for writes (16). Campaign data is mostly the advertiser's own, lead form responses are written by members, and no prompt-injection guidance was found (5). Entities carry created and last-modified times and the Developer Portal shows usage per endpoint. No audit log API found (5). security.txt names a HackerOne programme and has no Expires field. The DPA promises an annual SOC report and an ISO 27001 mapping on request. The HackerOne page needs JavaScript and was not read (14).

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.

## 5. Schema & documentation, 66 out of 100, up to 5.5 more on the total

Why it scored 66: No OpenAPI specification found. The docs link a public Postman workspace, which needs JavaScript and was not read (5). Every docs page we requested with `Accept: text/markdown` came back as Markdown with front matter. No llms.txt at learn.microsoft.com (8). Reference pages state limits and restrictions per endpoint, with use-case guides and a restricted-uses page (14). Field tables give type, required and enum values, but queries use Rest.li syntax such as `List(urn%3Ali%3AsponsoredAccount%3A...)` and nested targeting criteria (11). curl and HTTP samples on each method, error tables per endpoint and a structured error schema on three resources (13). Monthly versions selected by header and a dated changelog (15).

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.

## 6. Maintenance & community, 64 out of 100, up to 3.2 more on the total

Why it scored 64: Version 202609 is the latest and the changelog page is dated 16 September 2026 (30). Versions 202607, 202608 and 202609 fall inside the last 90 days (20). Closed API with a dated changelog, a support ticket form and a help assistant. Standard tier reviews can take up to 30 business days (9). The official Python and JavaScript clients are marked beta. PyPI's newest is 0.3.0 from 29 June 2023 and npm's is 0.3.0 (3). Both client repositories have CI workflows, with last commits in November 2023 and March 2023 (2).

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.

## 7. Transparency & trust, 84 out of 100, up to 1.4 more on the total

Made of editorial 74, provenance 94.

Why it scored 84: Closed API under the API terms of use (13 December 2022) and the Marketing API terms (25 July 2025), naming LinkedIn Corporation or LinkedIn Ireland Unlimited Company by region. The clients carry LinkedIn's own software licence (15). Privacy policy effective 3 November 2025, a DPA with 48-hour breach notice, a table of storage periods for API data, and reporting retention of ten years for performance data and two for demographics. The privacy policy gives no fixed retention periods (22). Each monthly version is supported for at least a year with a sunset date published, and the terms promise 30 days' notice before an API is discontinued, with security and legal exceptions (20). Subprocessor list dated 25 August 2026 with corporate locations (17).

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):

- Terms of service: published, but our reader couldn't read it (7 of 10)
- Privacy policy: published, but our reader couldn't read it (7 of 10)

## 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: the HackerOne programme page (JavaScript only), so bounty terms and scope were not read
- unchecked: the Postman workspace contents (JavaScript only), so whether the collections cover every endpoint is not established
- unchecked: the developer product catalogue and the Developer Portal's rate-limit figures, which need a signed-in app
- Whether LinkedIn holds SOC 2 or ISO 27001 certification for Marketing Solutions. The DPA mentions an annual SOC report and an ISO 27001 mapping on request, and no public trust page was read
- The release date of each monthly version is inferred from the changelog page date (16 September 2026) and the sunset dates, not stated per version
- Whether an official MCP server or OpenAPI specification exists outside the pages reviewed. None was found
- Whether API access is free under every tier. No fee was found, and no page states it

## Weaknesses

- Standard rate limits are not published. An app sees its limit in the Developer Portal only after calling the endpoint
- No OpenAPI specification, llms.txt or MCP server was found. The contract is reference pages and a Postman workspace
- Access needs a LinkedIn Page, an approved developer application and member consent. Standard tier review can take up to 30 business days
- No idempotency keys or Retry-After header were found in the reviewed documentation
- The official Python and JavaScript clients are marked beta and were last released in 2023

## 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.

- Send `Linkedin-Version: YYYYMM` and `X-Restli-Protocol-Version: 2.0.0` on every call. A missing or sunset version returns an error (426 for a deprecated one)
- Create one test ad account with `"test": true` and build there first. Its creatives are auto-rejected and never billed, and it returns no reporting data
- Create campaigns as DRAFT or PAUSED and check `servingStatuses` before activating. Some validation is postponed until activation
- Pass `fields=` on adAnalytics. Responses stop at 15,000 elements and the endpoint throttles at 45 million metric values per 5 minutes
- On Development tier, map each ad account to the app in the Developer Portal. Edits are limited to five accounts

## 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.