---
title: Help & Limits — Scholar Sidekick
description: How to use Scholar Sidekick — supported identifiers, styles, exports, caching, rate limits, and privacy.
doc_version: "1.0"
last_updated: "2026-02-13"
---

# Help & Limits — Scholar Sidekick

> How to use Scholar Sidekick: supported identifiers, styles, exports, caching, rate limits, and privacy.
> HTML version: https://scholar-sidekick.com/help

---

## Supported identifiers

Paste any of the following — Scholar Sidekick detects and normalises them automatically. You can mix types freely, one per line.

- **DOI** (e.g. `10.1038/nphys1170` or a doi.org URL). Includes a "healer" for minor typos.
- **PMID** (PubMed ID, e.g. `PMID: 30049270`)
- **PMCID** (PubMed Central ID, e.g. `PMC7793608`) — auto-maps to PMID/DOI if available
- **ISBN** (10 or 13 digit; dashes and spaces optional) — resolves via OpenLibrary, falls back to Google Books
- **ISSN / eISSN**
- **arXiv ID** (e.g. `arXiv:2301.07041` or bare `2301.07041`)
- **ADS bibcode** (NASA Astrophysics Data System)
- **WHO IRIS** handles and URLs

Free-text input is supported: identifiers are detected, normalised, and deduplicated per line.

---

## Citation styles & output

### Built-in styles (fastest)

| Style | ID |
|---|---|
| Vancouver | `vancouver` |
| AMA | `ama` |
| APA | `apa` |
| IEEE | `ieee` |
| CSE | `cse` |

### CSL styles

Any CSL style ID is accepted — Chicago, MLA, ACS, Nature, Lancet, and 10,000+ more via the CSL repository. Examples: `chicago-author-date`, `mla`, `acs-nano`, `nature`, `lancet`.

### Output formats

- `text` — plain text citation string
- `html` — HTML-formatted citation (can render as footnotes with `footnotes: true`)

---

## Export formats

| Format | Description |
|---|---|
| `txt` | Formatted plain-text citations |
| `bibtex` | BibTeX — for LaTeX, Overleaf, JabRef |
| `ris` | RIS — for Zotero, Mendeley, EndNote |
| `csl-json` | Raw CSL-JSON structured metadata |
| `endnote-xml` | EndNote XML |
| `refworks` | RefWorks tagged format |
| `nbib` | MEDLINE / NBIB |
| `rdf` | Zotero RDF |
| `csv` | Comma-separated values |

---

## Speed & caching

Recent lookups are cached so repeat requests are fast. Very new records may be briefly cached as "not found" — if you suspect a fresh registration, retry after a short delay.

- **UI:** append `?nocache=1` to bypass the cache
- **API:** the response includes `X-Scholar-Cache: BYPASS` or `ENABLED`

---

## Rate limits

If you send many requests quickly you may receive `429 Too Many Requests`. Back off per the `Retry-After` header.

**Rate limit headers returned on every response:**

| Header | Description |
|---|---|
| `X-RateLimit-Limit` | Requests allowed in the current window |
| `X-RateLimit-Remaining` | Requests remaining in the current window |
| `X-RateLimit-Reset` | Unix timestamp when the window resets |
| `Retry-After` | Seconds to wait (present on 429 only) |

Rate limit buckets differ by route (format, export, stream, etc.). Plan tiers: anonymous, free, pro, ultra, mega. See `/api/health` for a live snapshot.

---

## Errors

- Input errors return a friendly 4xx with a JSON body
- Per-identifier failures are reported at line level (the rest of the batch still succeeds)
- Error format: `{ "ok": false, "code": "BAD_REQUEST", "error": "human-readable message" }`
- Common codes: `BAD_REQUEST` (400), `UNAUTHORIZED` (401), `RATE_LIMITED` (429), `MAINTENANCE` (503)

---

## Privacy

- No account is required for core, one-off usage
- Citation inputs are processed on demand and not stored after the request completes
- Only minimal operational logs are retained
- No advertising, tracking, or profiling
- Inputs are not shared with third parties beyond the resolvers needed to fulfil the request (e.g. Crossref, PubMed)

Full details: https://scholar-sidekick.com/legal/privacy

---

## Related

- API Docs: https://scholar-sidekick.com/docs
- API Docs (markdown): https://scholar-sidekick.com/docs.md
- MCP Server: https://scholar-sidekick.com/mcp
- Service health: https://scholar-sidekick.com/api/health
- Privacy Policy: https://scholar-sidekick.com/legal/privacy

## Sitemap

See the full [sitemap](/sitemap.md) for all pages.