# /osf/registrations/search

`POST /api/osf/registrations/search`

Price: 20 credits

Search public OSF registrations by title, description, tag, subject, category and creation or modification date. Returns each registration's GUID, title, description, the form it was registered on, the date it was frozen, its embargo and withdrawal state and its declarations about available data, materials, code and papers.

## How to use it

Use this to find preregistrations and registered reports on a topic, then take a GUID to /osf/registrations for the answers the researchers actually gave. Rows carry no authors and no form answers. `registration_supplement` names the template, which is the practical way to tell a preregistration from a registered report or an open-ended archive — but OSF will not filter on it, so narrow another way and read it off the rows. There is no filter on the registration date either: `created_since` and `modified_since` are about the underlying project, so a registration frozen today from a project made in 2019 will not match a recent `created_since`. An embargoed registration appears here with its title while its content stays closed until `embargo_end_date`, and a withdrawn one appears with `is_withdrawn` true. `tag` and `subject` must match a whole term.

## Parameters

- `access-token` (string, required)

## Request body

- `timeout` (integer) — Max scrapping execution timeout (in seconds) (default: 300; min: 20; max: 1500)
- `title_contains` (string, nullable) — Keep only registrations whose title contains this text (examples: "memory"; minLength: 1)
- `description` (string, nullable) — Keep only registrations whose description contains this text (examples: "randomised"; minLength: 1)
- `tag` (string, nullable) — Keep only registrations carrying this tag, matched exactly (examples: "covid"; minLength: 1)
- `subject` (string, nullable) — Keep only registrations filed under this subject taxonomy term (examples: "Psychology"; minLength: 1)
- `category` (string, nullable) — Keep only registrations of this category (one of: "project", "analysis", "communication", "data", "hypothesis", "instrumentation", "methods and measures", "procedure", "software", "other")
- `created_since` (string, nullable) — Keep only registrations whose underlying project was created on or after this date, as YYYY-MM-DD (examples: "2026-01-01"; minLength: 1)
- `modified_since` (string, nullable) — Keep only registrations changed on or after this date, as YYYY-MM-DD (examples: "2026-01-01"; minLength: 1)
- `sort` (string) — Field the results are ordered by (default: "date_modified"; one of: "date_created", "date_modified", "title")
- `sort_direction` (string) — Ordering direction (default: "desc"; one of: "desc", "asc")
- `count` (integer, required) — Max number of results (examples: 100; min: 1; max: 300)

## Response

### 200 — Successful Response

- `@type` (string) (default: "OsfRegistration")
- `id` (string, required)
- `url` (string, required)
- `description` (string, nullable)
- `category` (string, nullable)
- `registration_supplement` (string, nullable)
- `created_at` (string, nullable)
- `modified_at` (string, nullable)
- `registered_at` (string, nullable)
- `withdrawn_at` (string, nullable)
- `embargo_end_date` (string, nullable)
- `reviews_state` (string, nullable)
- `revision_state` (string, nullable)
- `article_doi` (string, nullable)
- `archive_url` (string, nullable)
- `withdrawal_justification` (string, nullable)
- `tags` (array) (default: [])
- `subjects` (array) (default: [])
  - `@type` (string) (default: "OsfSubject")
  - `id` (string, required)
  - `text` (string, required)
  - `path` (array) (default: [])
- `license_record` (object, nullable)
  - `@type` (string) (default: "OsfLicenseRecord")
  - `year` (string, nullable)
  - `copyright_holders` (array) (default: [])
- `is_public` (boolean, nullable)
- `is_embargoed` (boolean, nullable)
- `is_withdrawn` (boolean, nullable)
- `is_archiving` (boolean, nullable)
- `is_fork` (boolean, nullable)
- `is_collection` (boolean, nullable)
- `is_preprint` (boolean, nullable)
- `is_wiki_enabled` (boolean, nullable)
- `has_project` (boolean, nullable)
- `has_data` (boolean, nullable)
- `has_materials` (boolean, nullable)
- `has_analytic_code` (boolean, nullable)
- `has_papers` (boolean, nullable)
- `has_supplements` (boolean, nullable)
- `is_pending_registration_approval` (boolean, nullable)
- `is_pending_embargo_approval` (boolean, nullable)
- `is_pending_embargo_termination_approval` (boolean, nullable)
- `is_pending_withdrawal` (boolean, nullable)
- `are_access_requests_enabled` (boolean, nullable)

## Errors

### 422 — Validation Error

The request body did not validate

What to do: Check the fields against this schema. A URN with the wrong prefix is the most common cause.

- `detail` (array)
  - `loc` (array, required)
  - `msg` (string, required)
  - `type` (string, required)
  - `input` (any)
  - `ctx` (object)

### 408

The request ran past its time limit

What to do: Raise `timeout` in the request body, up to the maximum this endpoint documents. Lowering `count` or turning off the `with_*` flags also helps, because less work finishes sooner.

### 412

The entity was not found, or a precondition failed

What to do: Retrying will not help: either the entity does not exist, or the input points at a different one.

### 429

Too many requests: a rate limit or a usage window is exhausted

What to do: When the response carries an X-Retry-After header, wait that many seconds and retry: the same number is in the body as `detail.retry_after`, and the limit clears once that window passes. The message in the body names the limit that was hit.

### 500

Something broke on our side

What to do: Retrying will not help. If it keeps happening, send us the X-Request-ID from the response headers.

### 529

Rate limit reached, or the endpoint is overloaded

What to do: Wait at least 30 seconds, then retry.

## Response envelope

Success: Array of objects (may be empty if no results)

Error: Error may coexist with partial results if it occurs mid-execution. Check X-Error header and status code.

Every response carries these headers:

- `X-Error` — Error message text (present only on error)
- `X-Request-ID` — Unique request identifier
- `X-Execution-Time` — Execution time in seconds
- `X-Result-Count` — How many records the body carries. 0 means an empty result, which is a normal answer and not by itself an error. A non-zero count can come back together with X-Error when the failure happened partway through — read this header and X-Error independently.
- `X-Total-Available-Results` — How many records exist for this query, when the endpoint can say. On a `dry_run` request this is the answer and the body is empty. It saturates: the endpoint's documented maximum means 'at least that many', any smaller number is exact.
- `X-Warning` — Present when the request body carried keys this endpoint does not document. They were ignored, so any filter you meant to apply through them did not apply. Check the spelling against this schema and retry.
- `X-Retry-After` — Seconds to wait before retrying. Present only on 429.