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lemmy.communities

stable Advanced

Popular Lemmy communities on an instance.

GET /v1/lemmy/communities

What you get#

A list of Lemmy results in Onekey's unified shape, in data (an array). An empty array is a normal, successful answer and is charged like any other; a source that reports "nothing found" as an error returns a free 404 not_found instead.

What it costs#

  • Advanced · 5 credits for a fresh fetch, charged only when it succeeds.
  • Free when served from cache (0.2 credit for a cached response over 100 KB).
  • Free if the request is invalid (never charged) or the source fails or reports not found (refunded).

Parameters#

NameTypeRequiredDefaultWhat it isConstraints
instancestringno-Known Lemmy instance (allowlisted), default lemmy.worldmax 253 chars; must match [a-z0-9.-]{3,253}; trimmed, lowercased

Request#

curl "https://api.onekey.dev/v1/lemmy/communities" \
  -H "x-api-key: YOUR_API_KEY"

Try it

Add your key to run this call right here. No key? Get one free. The key stays in this tab.

Recorded response#

A real Lemmy response, recorded and returned in Onekey's shape. Fields the platform does not provide are null.

json
{
  "success": true,
  "data": [
    {
      "content": {
        "id": "2478",
        "title": "Technology",
        "text": "This is a [most excellent](https://media.giphy.com/media/v1.Y2lkPTc5MGI3NjExN3N0NmhuODNib3d3Nzg0OHU2bTFqMXAzNW42Y2JsOTVmenNsNG8ycSZlcD12MV9pbnRlcm5hbF9naWZfYnlfaWQmY3Q9Zw/l46CDHTqbmnGZyxKo/giphy.gif) place for technology news and articles.\n \n---\n \n## Our Rules\n \n---\n \n1. Follow the [lemmy.world rules.](https://mastodon.world/about) \n2. Only tech related news or articles.\n3. Be [excellent to each other!](https://www.youtube.com/watch?v=rph_1DODXDU)\n4. Mod approved content bots can post up to 10 articles per day.\n5. Threads asking for personal tech support may be deleted.\n6. Politics threads may be removed.\n7. No memes allowed as posts, OK to post as comments.\n8. Only approved bots from the list below, this includes using AI responses and summaries. To ask if your bot can be added please contact a mod.\n9. Check for duplicates before posting, duplicates may be removed\n10. Accounts 7 days and younger will have their posts automatically removed. \n \n---\n \n## Approved Bots\n \n---\n \n- [@L4s@lemmy.world](https://lemmy.world/u/L4s) \n- [@autotldr@lemmings.world](https://lemmings.world/u/autotldr) \n- [@PipedLinkBot@feddit.rocks](https://feddit.rocks/u/PipedLinkBot) \n- [@wikibot@lemmy.world](https://lemmy.world/u/wikibot) ",
        "createdAt": "2023-06-11T02:16:17Z"
      },
      "entity": {
        "name": "technology",
        "url": "https://lemmy.world/c/technology",
        "stats": {
          "followers": 88298
        }
      },
      "media": {
        "thumbnailUrl": "https://lemmy.world/pictrs/image/2a85bf08-5c07-4326-8dad-f549bfb2189e.png"
      },
      "ext": {
        "posts": 21955
      },
      "engagement": {
        "comments": 959056
      }
    },
    {
      "content": {
        "id": "116",
        "title": "Selfhosted",
        "text": "A place to share alternatives to popular online services that can be self-hosted without giving up privacy or locking you into a service you don't control.\n\nRules:     \n\n[Detailed Rules Post](https://lemmy.world/post/48725669)\n\n1) Be civil.\n\n2) No spam.\n\n3) Posts are to be related to self-hosting.\n\n4) Don't duplicate the full text of your blog or readme if you're providing a link.\n\n5) Submission headline should match the article title.\n\n6) No trolling.\n\n7) Promotion posts require active participation, with an account that is at least 30 days old. F/LOSS without a paywall has exceptions, with requirements.   See the [rules link](https://lemmy.world/post/48725669) for details.  Tags [CBH] or [AIP] are **required**, see the links in Rule 8 for details.\n\n8) AI-related discussions and AI-involved promotional posts have additional requirements for tagging, as noted in Rule 7 and the [AI & Promotional Post Expanded Rules](https://lemmy.world/post/49151085) post, and find [example disclosures here](https://lemmy.world/post/49320548).\n\n\nResources:     \n\n-  [selfh.st](https://selfh.st/) Newsletter and index of selfhosted software and apps    \n- [awesome-selfhosted software](https://github.com/awesome-selfhosted/awesome-selfhosted)    \n- [awesome-sysadmin](https://github.com/awesome-foss/awesome-sysadmin) resources    \n- [Self-Hosted Podcast from Jupiter Broadcasting](https://selfhosted.show/)\n\n> Any issues on the community? Report it using the report flag.\n\n> Questions? DM the mods!",
        "createdAt": "2023-06-05T11:23:43Z"
      },
      "entity": {
        "name": "selfhosted",
        "url": "https://lemmy.world/c/selfhosted",
        "stats": {
          "followers": 62373
        }
      },
      "media": {
        "thumbnailUrl": "https://lemmy.world/pictrs/image/8286e071-7449-4413-a084-1eb5242e2cf4.png"
      },
      "ext": {
        "posts": 6761
      },
      "engagement": {
        "comments": 172227
      }
    }
  ],
  "metadata": {
    "platform": "lemmy",
    "endpoint": "communities",
    "cached": false,
    "stale": false,
    "age_s": 0,
    "fetched_at": "2026-01-01T12:00:00+00:00",
    "credits_charged": 5,
    "request_id": "7f3a9c2e5b1d4c8fa2e6d0b9c4f18e37"
  },
  "error": null
}

Field mapping#

How this endpoint's source fields become Onekey's unified schema. Fields the source lacks come back as null.

Source pathOnekey fieldTransform
community.idcontent.idtoString
community.nameentity.name-
community.titlecontent.title-
community.descriptioncontent.text-
community.actor_identity.urlsafeUrl
community.iconmedia.thumbnailUrlsafeUrl
community.publishedcontent.createdAttoIsoDate
counts.subscribersentity.stats.followerstoNumber
counts.postsext.poststoNumber
counts.commentsengagement.commentstoNumber

Caching and freshness#

  • Fresh for about 2 minutes. Repeat calls in that window are served from cache and are free.
  • Between 2 minutes and 15 minutes the cached copy is still served instantly and marked stale: true while Onekey refreshes it in the background.
  • If the source is down when a refresh is needed, the last copy can be served for up to 1 hour more (marked stale).
  • A "not found" is remembered for 1 minute and is free.
  • The cache is shared across all customers, which is what keeps repeat calls cheap.

What can go wrong#

StatusCodeWhat to do
401unauthorizedCheck the x-api-key header.
402insufficient_creditsAdd credits; your balance must cover the price.
404not_foundUnknown endpoint path.
422invalid_paramsFix the parameters using the table above. Free.
429rate_limitedWait Retry-After seconds, then retry.
502upstream_errorThe source failed. Refunded; retry with backoff.

See Errors for the full list and retry guidance.

Status: stable (verified against the live source).