MailerLite is Good to agents.
Discry independently scored how well an AI agent can discover and understand the MailerLite API from what’s public — not whether it’s usable. Below: every signal we checked, what’s costing the score, and what to change.
SCORED UNDER RUBRIC 1.2 · A full re-launch under Discry Score 2.5 — a new behavioral instrument, not comparable to these scores — is in progress.
Discovery
45% of score · 69/100Comprehension
55% of score · 96/100What we found
- An agent can discover MailerLite's API with almost no friction: robots.txt allows every crawler, and the developer docs ship a well-structured, API-focused llms.txt, a 320KB comprehensive llms-full.txt, and a full sitemap covering every endpoint page.
- MailerLite is unusually agent-native for its category — it publishes an official hosted MCP server (listed on PulseMCP, Smithery and Glama), an official CLI, and a dedicated Agent Skills repo (mailerlite/mailerlite-skills), so an agent can act on the account without hand-rolling HTTP calls.
- Comprehension is near-best-in-class: every endpoint page leads with method + URL + purpose, uses realistic copy-pasteable JSON examples (real-looking emails and IDs), offers a per-page 'Copy Markdown'/'Ask AI' affordance, and is backed by six official language SDKs.
- Failure handling is agent-friendly: on a 429 the docs explicitly tell the caller to read Retry-After, use the batch endpoint, and back off, and 422 responses return the exact offending field — an agent can self-correct rather than guess.
- The score is held back on discovery, not comprehension: there is no first-party machine-readable OpenAPI spec (only a third-party derived one), no .well-known/mcp.json, and no AGENTS.md — plus a minor field-naming inconsistency (z_i_p vs zip) that could trip a strict agent.
What to change
Prioritized by impact on discoverability. You (or your docs platform) deploy these — Discry never touches your API.
- 01Publish an official OpenAPI 3.x spec at a stable URL (e.g. developers.mailerlite.com/openapi.json) and link it from the docs — this is the single biggest discovery lever (weight 5) and lets agents auto-generate typed clients.
- 02Add a .well-known/mcp.json that advertises the existing hosted MCP server so agents can auto-discover it during a capability probe instead of relying on registry search.
- 03Add an AGENTS.md to the primary SDK repos (or surface the existing mailerlite-skills repo from the docs) to give coding agents explicit build/usage context.
- 04Resolve the z_i_p vs zip field-name inconsistency so agents get one stable key for the ZIP field across all responses.
Execution coverage · INFORMATIONAL, UNSCORED
Whether an agent can actually complete a call and recover from errors is the deeper Audit layer — documented here, but not part of the Discry Score.
Auth is a single machine-to-machine model: a Bearer API key generated in-dashboard. Errors are machine-parseable JSON ({message, errors{}}) with field-level validation detail. Rate limits are explicit — global 120 req/min plus a separate 5 req/min import limit — with X-RateLimit-Limit, X-RateLimit-Remaining and Retry-After headers. Pagination is documented (cursor-based for subscribers, page-based for campaigns/groups). No idempotency keys, but POST /subscribers is documented as a non-destructive upsert.