---
title: "Journal profile by ISSN"
method: GET
path: "/api/v1/research/crossref/journal/{issn}"
tags: ["Research"]
---

# Journal profile by ISSN

`GET /api/v1/research/crossref/journal/{issn}`

Fetch a single journal record by ISSN (print or electronic). Returns the journal's title, publisher, subjects, DOI counts (current, backfile, total), per-feature coverage metrics (abstracts, ORCIDs, references, licenses, awards), and deposit flags telling you which features the publisher supplies for current vs backfile content. Data licensed CC0 by Crossref.

## Path parameters

- `issn` string, required — Journal ISSN in NNNN-NNNX form (e.g. `0028-0836` for Nature).

## Response `200`

Full journal record with ISSNs, counts, coverage, and flags.

- EnvelopeCrossrefJournalPayload
  - `data` CrossrefJournalPayload, required — Response payload for `/api/v1/research/crossref/journal/{issn}`.
    - `journal` CrossrefJournal, required — Single journal record returned under `message` of `/journals/{issn}`.
      - `ISSN` string[], nullable — ISSNs attached to the journal (print and electronic).
      - `issn-type` CrossrefIssnType[], nullable — Typed ISSN entries identifying print vs electronic forms.
        - `value` string, nullable — ISSN string (8 chars including hyphen).
        - `type` string, nullable — ISSN type (`print`, `electronic`, `linking`).
      - `title` string, nullable — Journal title.
      - `publisher` string, nullable — Publisher name as filed with Crossref.
      - `subjects` object[], nullable — Assigned subject categories for the journal.
      - `counts` CrossrefJournalCounts — DOI counts reported on a journal record.
        - `current-dois` integer, nullable — Number of DOIs deposited in the last 2 years (rolling).
        - `backfile-dois` integer, nullable — Number of DOIs deposited more than 2 years ago.
        - `total-dois` integer, nullable — Total DOIs registered for this journal.
      - `breakdowns` object, nullable — Per-year DOI counts (`dois-by-issued-year`) when published by Crossref.
      - `coverage` object, nullable — Coverage metrics per deposit feature (abstracts, ORCIDs, references, licenses, awards).
      - `flags` object, nullable — Deposit flags indicating which features the publisher supplies for current and backfile content.
      - `last-status-check-time` integer, nullable — Millisecond UNIX timestamp of Crossref's last flags/coverage snapshot for this journal.
  - `meta` SugraMeta, required — Metadata attached to every /api/v1/* response envelope.
    - `endpoint` string, required — Requested endpoint path.
    - `data_time` string, required — ISO 8601 UTC timestamp of the source data, not of the request.
    - `response_time` string, required — ISO 8601 UTC timestamp when this response was produced.
    - `provider` string, required — API name and version.
    - `source` string, nullable — Identifier of the primary upstream source used for this response.
    - `attribution` string, nullable — Human-readable attribution mandated by an upstream source (e.g. a securities regulator or self-regulatory organization). Present only on responses whose source requires the owner and source to be clearly identified. Do not remove or alter it when using the response.
    - `fallback_used` boolean, nullable — True when the primary source failed and a fallback produced the data.
    - `fallback_chain` string[], nullable — Ordered list of sources attempted, in the order they were tried.
    - `cached` boolean, nullable — True when this response was served from the internal cache.
    - `stale` boolean, nullable — True when the cached response was returned after the upstream rate-limited or errored. Clients can use this to detect degraded data.

## Other responses

- `401` — Missing or invalid `x-api-key` header. JSON body with a stable `code` distinguishing `missing_api_key` (no header sent) from `invalid_api_key` (header sent, key not accepted); any other 401 source carries the generic `unauthorized` with its detail as `reason`. Plus `hint`. `plan` is always null on 401 - an unauthenticated request has no plan; quota exhaustion is 429, not 401.
- `422` — Validation Error
- `429` — Daily rate limit exceeded. Check `X-RateLimit-Reset` for the next window.
- `503` — Upstream source is temporarily unavailable. Retry after a short delay.

---

[API](https://skmtc.net/sugra/apis/sugra-api.md) · [All operations](https://skmtc.net/sugra/apis/sugra-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/sugra/sugra-api/versions/d3e3d9c28132/schema)