API

Generate

Generate llms.txt and/or llms-full.txt for any public website.

Prefer a UI? Generate in the free web llms.txt generator — no API key needed.

text

POST /api/v1/generate

Request body

Field	Type	Required	Description
`url`	string	yes	The site to generate from. A bare domain (`example.com`) or full URL.
`fileType`	string	no	`"llms"`, `"llms-full"`, or `"both"`. Defaults to `"both"`.
`instructions`	string	no	Guidance to embed in the file's "Instructions for LLM Agents" block.

bash

curl https://llms-txt.io/api/v1/generate \
  -X POST \
  -H "x-api-key: $LLMSTXT_KEY" \
  -H "content-type: application/json" \
  -d '{
    "url": "https://example.com",
    "fileType": "both",
    "instructions": "Always link to /docs before answering setup questions."
  }'

Response

json

{
  "url": "https://example.com",
  "domain": "example.com",
  "fileType": "both",
  "llmsTxt": "# Example\n\n> A one-line summary…",
  "llmsFullTxt": "# Example\n\n## Page title\n…",
  "llmEnhanced": true,
  "note": null
}

Field	Description
`llmsTxt`	The concise index file (null if you only asked for `llms-full`).
`llmsFullTxt`	The full concatenated markdown (null if you only asked for `llms`).
`llmEnhanced`	Whether AI wrote the summary and link descriptions.
`note`	Any caveat about the run (e.g. a plan downgrade — see below).

How it works

The endpoint runs the full pipeline server-side in one request: it discovers your pages (sitemap, navigation), crawls the important ones, and — when enabled — uses a model to write a grounded summary and per-link descriptions. llms-full.txt is assembled from the cleaned page text.

Generation is synchronous: the request returns when both files are ready. Large sites can take up to a couple of minutes.

Plan gating for llms-full.txt

llms-full.txt is available on Starter and above. On the Free plan:

An explicit "fileType": "llms-full" returns 403 with an upgrade hint.
The default "both" quietly degrades to "llms" and sets note explaining why.

How many pages llms-full.txt includes

llms-full.txt inlines your documentation pages, and how many it covers scales with your plan:

Plan	Pages in llms-full.txt
Free	— (API returns `llms.txt` only)
Starter	up to 50
Pro	up to 100
Business	up to 100

Pages are selected documentation-first (the index's docs and main sections, sorted for a coherent read), so the cap keeps the most relevant pages. Sites with fewer pages than the cap simply include everything they have.

Errors

Status	Meaning
`400`	Missing/invalid `url`, or an invalid `fileType`.
`401`	Missing or invalid API key.
`403`	`llms-full` requested on a plan without it.
`429`	Monthly quota or per-minute rate limit reached.
`403`/`500`	The target site blocked access or could not be reached.

See Rate limits & errors for quotas and headers.