AuthorizationstringrequiredheaderRequired Bearer API key. Programmatic access to the World API needs a key; browsing nosible.world in a browser does not.
Example: Bearer nos_sk_...
Similar events
Find semantically similar events to a canonical event.
Parameters
query & pathviewenumqueryThe record each event is returned as: lite (the default), the event without its evidence, or full, the complete record. Any other value is a 422 validation_error. About records on Event details lists both.
Example: lite
include_vectorbooleanquerytrue adds each event's embedding, oai_vector (3,072 values, comma-separated), to either view. Defaults to false.
Example: false
datedaterequiredpathArchive date in YYYY-MM-DD format.
Example: 2026-07-20
event_idstringrequiredpathCanonical event identifier.
Example: 2026-07-20_en_JP_v1_NQA5mXKS5x7MUUbwQAAAABDCQAAAInpsKAEpoAAAAAA_ehrkVV2W
limitintegerqueryMaximum neighbors to return.
Example: 10
include_livebooleanqueryAlso search the live days after the archive cutoff. Defaults to false.
Example: false
include_threadbooleanqueryInclude stored story-thread predecessors (none are stored in the current archive).
Example: true
How to use this endpoint
guidanceUse Similar Events to discover historical analogues and story threads. Similarity is a ranking signal, not a claim that two events are causally related. neighbors are computed against the archive-wide HNSW index. thread is reserved for a stored backwards story chain; the current archive stores none, so it is empty.
Response body
application/jsonThese are the fields you can build against. Nested names use dot notation; optional sections are called out in their descriptions.
schemastringResponse schema name.
viewstringThe view the events are returned in: lite (the default) or full. See About records on Event details.
include_vectorbooleantrue when the request asked for the embedding with include_vector=true; absent otherwise.
event_idstringThe event the neighbours are similar to.
datedateIts date.
limitintegerNeighbour cap applied.
floordateEarliest date a neighbour may have: the start of the archive your key can read.
min_similaritynumberSimilarity floor applied.
neighborsobject[]The most similar events across the archive, most similar first, each a record in the requested view (lite unless view=full) with its similarity and retrieval.
neighbors[].event_idstringStable event identifier.
neighbors[].versionstringEvent record version: "2.0-preview".
neighbors[].eventobjectThe event in its original language: date, language, title, description and points.
neighbors[].event.datedateWorld archive date of the event.
neighbors[].event.languagestringISO 639-1 code of the event's original language.
neighbors[].event.titlestringHeadline, in the original language.
neighbors[].event.descriptionstringShort narrative, in the original language.
neighbors[].event.pointsstring[]Key facts of the event, one sentence each.
neighbors[].englishobjectThe event in English: title, description and points, translated when the original language is not English.
neighbors[].coverageobjecttotal_coverage, total_netlocs, coverage_concentration_index, first_seen, last_seen and most_seen, as in Event details.
neighbors[].locationsobject[]Places of the event, its own place first, then places named in it, as in Event details.
neighbors[].signalsobjectSentiment, materiality, time horizon and forward-looking signals with their class probabilities, as in Event details.
neighbors[].tickersobject[]Listed companies the event concerns, in the Event details format without why. Empty when has_tickers is false.
neighbors[].has_tickersbooleanWhether tickers is non-empty.
neighbors[].entitiesobjectNamed entities by NER type, {TYPE: [{name, mention_count, confidence}]}, as in Event details.
neighbors[].sentimentsobjectEntity-level sentiment grouped by entity type. Each item has name, sentiment_label (positive, neutral or negative), and sentiment_score, the final Percentage Margin Z-score.
neighbors[].ontologiesobject[]Classifications of the event, most probable first, as in Event details.
neighbors[].oai_vectorstringOnly with include_vector=true: the event's 3,072-dimension embedding (text-embedding-3-large), comma-separated.
neighbors[].similaritynumberCosine similarity of the two events' embeddings.
neighbors[].retrievalstringWhere the neighbour was found, such as archive_hnsw (the archive's vector index).
threadobject[]Stored story-chain predecessors, records like neighbors. Always empty in V2.0: its events carry no stored story chain, so use neighbors.
errorsobject[]Non-fatal retrieval errors; empty when none.
took_msintegerServer time in milliseconds.
Responses and errors
HTTP200Request succeeded. The response body is shown in the panel on the right.
400
invalid_json — The request body is not JSON. Every error body, 401 included, is {error, message, status}.401
api_key_required — No API key was sent. Send it as Authorization: Bearer <key> or the api-key header.401
invalid_api_key — The API key is invalid or has been revoked.403
access_denied — The requested archive date is outside the caller's World tier.422
validation_error — The request is well formed but the API cannot decode or validate it: an unknown body field or query parameter, a missing required parameter, a value of the wrong type, an empty and, or or not, a date that is not a calendar date (in the path, the query or the body), an unknown enum value or a reversed range. The message names the parameter and what is wrong.404
not_found — The requested date, entity, ticker, or event does not exist in the accessible index.410
cursor_expired — The cursor was minted against a replaced index build. Restart pagination from the first page.429
rate_limited — The request exceeded the endpoint or account rate limit. Respect Retry-After when supplied.501
backend_not_configured — The World backend is not configured for this deployment.503
api_key_auth_unavailable — API key authentication is temporarily unavailable; retry shortly.503
api_key_metering_unavailable — API key usage metering is temporarily unavailable, so the request was not served; wait for the Retry-After header (30 seconds) and retry.502
backend_error — The World backend could not be reached or did not return a valid response; retry shortly.504
backend_timeout — The World backend did not answer within 300 seconds; narrow the request (for example with a date window) or retry.