--- title: "Domain Authority reference" url: "https://lookvalid.com/docs/api/domain-authority.md" canonical_url: "https://lookvalid.com/docs/api/domain-authority" last_updated: "2026-10-22" type: "reference" summary: "Request and response reference for Domain Authority: parameters, response fields, credit cost and error codes." related: ["https://lookvalid.com/docs/errors.md"] --- # Domain Authority reference Request and response reference for Domain Authority: parameters, response fields, credit cost and error codes. A 0 to 100 authority score for a domain, with every input shown: its Common Crawl web graph harmonic centrality and PageRank positions and its Majestic Million rank and referring subnets. Only domains inside the top of the open rank lists are scored; an unranked domain is not proof of low authority. It is a link-graph score, not Moz or Semrush authority. ```http POST https://YOUR_API_HOST/v1/domain-authority ``` ## Credits and caching - Success billing. 10 credits per domain found in the rank data (an unranked domain is free). You are charged only when the lookup finds something; a not-found result is free. - Results are cached per account for 7 days. Repeating the same lookup in that window is free and returns `cache_hit: true`. - Invalid input, rate limits and errors are never charged. - Read the [billing rules](https://lookvalid.com/docs/credits-and-billing.md) for the full picture. ## Request Send a JSON body with `Authorization: Bearer `. The body can be up to 64 KB. | Field | Type | Required | Notes | | --- | --- | --- | --- | | `domain` | string | yes | Up to 253 characters. | ### Example request **cURL** ```sh curl -X POST https://YOUR_API_HOST/v1/domain-authority \ -H "Authorization: Bearer $LOOKVALID_API_KEY" \ -H "Content-Type: application/json" \ -d '{"domain":"wikipedia.org"}' ``` **Node.js** ```js const response = await fetch("https://YOUR_API_HOST/v1/domain-authority", { method: "POST", headers: { Authorization: `Bearer ${process.env.LOOKVALID_API_KEY}`, "Content-Type": "application/json", }, body: JSON.stringify({ "domain": "wikipedia.org" }), }); const result = await response.json(); if (!response.ok) throw new Error(`${result.error.code}: ${result.error.fix}`); console.log(result.found, result.data, result.credits_charged); ``` **Python** ```python import os import requests response = requests.post( "https://YOUR_API_HOST/v1/domain-authority", headers={"Authorization": f"Bearer {os.environ['LOOKVALID_API_KEY']}"}, json={ "domain": "wikipedia.org", }, timeout=30, ) result = response.json() if not response.ok: raise RuntimeError(f"{result['error']['code']}: {result['error']['fix']}") print(result["found"], result["data"], result["credits_charged"]) ``` ## Response The status is 200 whether or not anything was found. Check `found`. Every response also carries the `X-Request-Id`, `X-Credits-Charged`, `X-Credits-Remaining` and `X-RateLimit-*` headers. ### Envelope | Field | Type | Notes | | --- | --- | --- | | `request_id` | string | - | | `product` | "domain-authority" | - | | `found` | boolean | False means the lookup ran and found nothing; it is free. | | `reason` | string or null | Why nothing was found; null when found. | | `sources` | array of string | Where the data came from, including any attribution the licence requires. | | `credits_charged` | integer | 0 for a cache hit, a not-found result or an error. | | `credits_remaining` | integer | - | | `cache_hit` | boolean | True when the account already paid for this lookup within the cache window. | | `cache` | object | - | ### The `data` object Present when `found` is true, otherwise `null`. | Field | Type | Notes | | --- | --- | --- | | `domain` | string | - | | `matched_domain` | string | The domain the ranks belong to; a parent of the input when the input is a subdomain | | `authority_score` | integer | Minimum 0. Maximum 100. | | `signals` | object | - | | `signals.common_crawl` | object | - | | `signals.common_crawl.in_index` | boolean | - | | `signals.common_crawl.release` | string or null | - | | `signals.common_crawl.harmonic_position` | integer or null | - | | `signals.common_crawl.harmonic_value` | number or null | - | | `signals.common_crawl.pagerank_position` | integer or null | - | | `signals.common_crawl.pagerank_value` | number or null | - | | `signals.common_crawl.hosts_in_domain` | integer or null | - | | `signals.common_crawl.domains_in_release` | integer or null | - | | `signals.common_crawl.harmonic_signal` | number | - | | `signals.common_crawl.pagerank_signal` | number | - | | `signals.majestic` | object | - | | `signals.majestic.in_index` | boolean | - | | `signals.majestic.rank` | integer or null | - | | `signals.majestic.referring_subnets` | integer or null | - | | `signals.majestic.referring_ips` | integer or null | - | | `signals.majestic.list_size` | integer or null | - | | `signals.majestic.signal` | number | - | | `formula` | string | - | | `weights` | object | - | | `weights.common_crawl_harmonic` | number | - | | `weights.common_crawl_pagerank` | number | - | | `weights.majestic` | number | - | | `notes` | string | - | ### Captured example (2026-10-18) A real run of this lookup on 2026-10-18, using the request above, which is a public input. The envelope fields are left out. ```json { "product": "domain-authority", "found": true, "data": { "domain": "wikipedia.org", "matched_domain": "wikipedia.org", "authority_score": 83, "signals": { "common_crawl": { "in_index": true, "release": "cc-main-2026-jul-aug-sep", "harmonic_position": 14, "harmonic_value": 21064202, "pagerank_position": 35, "pagerank_value": 0.0008494547219015658, "hosts_in_domain": 2050, "domains_in_release": 133241980, "harmonic_signal": 85.9, "pagerank_signal": 81 }, "majestic": { "in_index": true, "rank": 12, "referring_subnets": 227466, "referring_ips": 698536, "list_size": 1000000, "signal": 82 } }, "formula": "authority_score = round(0.4 * harmonic + 0.2 * pagerank + 0.4 * majestic). Each signal = 100 * (1 - log10(position) / log10(list size)), so position 1 is 100 and the last position of the full list is 0. A list that does not hold the domain contributes 0. harmonic and pagerank are the Common Crawl web graph positions among all domains in the release; majestic is the Majestic Million global rank.", "weights": { "common_crawl_harmonic": 0.4, "common_crawl_pagerank": 0.2, "majestic": 0.4 }, "notes": "Scores come from open link-graph and popularity lists, not from Moz or Semrush, so they will not match those tools. Only the best-ranked domains of each list are indexed; a domain that is not found is not proof of low authority." }, "sources": [ "Common Crawl Web Graph (commoncrawl.org)", "Majestic Million (majestic.com/reports/majestic-million), licensed CC BY 3.0" ] } ``` ## Errors - `400` [`invalid_input`](https://lookvalid.com/docs/errors.md#invalid_input): The request input is invalid. - `401` [`unauthorized`](https://lookvalid.com/docs/errors.md#unauthorized): The API key is missing, malformed, revoked or unknown. - `402` [`insufficient_credits`](https://lookvalid.com/docs/errors.md#insufficient_credits): The account does not have enough credits for this lookup. Error code: insufficient_credits. During a trial whose allowance is used up the code is trial_allowance_exhausted: nothing is charged and the customer starts the plan from the billing page. - `405` [`method_not_allowed`](https://lookvalid.com/docs/errors.md#method_not_allowed): This endpoint does not accept that HTTP method. - `413` [`payload_too_large`](https://lookvalid.com/docs/errors.md#payload_too_large): The request body is too large. - `429` [`rate_limited`](https://lookvalid.com/docs/errors.md#rate_limited): Too many requests for this API key. - `500` [`internal_error`](https://lookvalid.com/docs/errors.md#internal_error): An unexpected error occurred. - `503` [`provider_unavailable`](https://lookvalid.com/docs/errors.md#provider_unavailable): The data source for this product is unavailable right now. ## Related - [Errors](https://lookvalid.com/docs/errors.md)