--- title: Formats and versions description: Markdown, JSON and plain text for every paper, figure assets, versioned and unversioned URLs, and how responses are cached. sidebar: order: 3 --- Every format is a rendering of the same [document tree](/document-model). ## Formats | Extension | Content-Type | Contents | | --------- | ------------------------------ | ---------------------------------------------------------------------------------------------------------------------- | | `.md` | `text/markdown; charset=utf-8` | YAML front matter, `# Title`, `## Abstract`, sections, LaTeX math, GFM tables, figures, `## References`, footnotes | | `.json` | `application/json` | Metadata, build info, token count, the full tree and inferred fields. See [JSON schema](/json) | | `.txt` | `text/plain; charset=utf-8` | Plain text: headings as plain lines, math kept as LaTeX, tables tab-separated, `References` and `Footnotes` at the end | ```bash curl https://arxivv.org/1706.03762.md curl https://arxivv.org/1706.03762.json curl https://arxivv.org/1706.03762.txt ``` ## Markdown conventions | Element | Rendering | | --------------- | ------------------------------------------------------------------------------------------------------------ | | Front matter | `arxiv`, `version`, `title`, `authors`, `date`, `categories`, `license` (when known), `url` (arXiv abstract) | | Title | `# Attention Is All You Need` | | Abstract | `## Abstract` | | Section heading | Level-1 sections are `##`, subsections `###`, then `####`: `### 3.2 Attention {#S3.SS2}` | | Inline math | `$d_k$` | | Display math | `$$...$$` followed by ` (1)` on the same line when numbered | | Citation | `[12]`, as printed in the paper | | Cross-reference | `[2](#S3.F2)`: the printed text, linked to the target id | | Figure | `![alt](https://arxivv.org/1706.03762v7/assets/Figures/ModalNet-21.png)` then `*Figure 1: caption*` | | Table | `*Table 1: caption*` then a GFM table (first row is the header row, `\|` escaped) | | Theorem | `**Theorem 1 (title).**` then the body; proofs start `*Proof.*` | | Footnote | `[^footnote3]`, defined at the very end | | Bibliography | Numbered list under `## References` | Image URLs are absolute and point at the [asset route](#figure-assets). Alt text is the image's own alt, or the figure caption. ```markdown --- arxiv: "1706.03762" version: 7 title: "Attention Is All You Need" authors: "Ashish Vaswani, Noam Shazeer, Niki Parmar, ..." date: "2023-08-02" categories: ["cs.CL", "cs.LG"] license: "http://creativecommons.org/licenses/by/4.0/" url: "https://arxiv.org/abs/1706.03762v7" --- # Attention Is All You Need ## Abstract The dominant sequence transduction models are based on complex recurrent or convolutional neural networks... ## 3 Model Architecture {#S3} ### 3.2 Attention {#S3.SS2} ``` `//sections/.md` returns one section subtree in the same form, heading included, followed by the definitions of any footnotes it uses. ## Figure assets `//assets/` serves a file referenced by arXiv's HTML, such as a figure image. `` is the image's `src` in the tree, e.g. `Figures/ModalNet-21.png`. | Property | Value | | ------------- | ------------------------------------------------------------------------------------------------------------------- | | Availability | Mirrored from arXiv asynchronously after the first build; `404 not-found` until mirrored | | Content-Type | As stored from arXiv, else `application/octet-stream` | | Cache-Control | Versioned: `public, max-age=31536000, immutable`; unversioned: `public, max-age=3600, stale-while-revalidate=86400` | | Headers | `ETag`, `X-Arxivv-Schema`, `X-Arxivv-Version`; `Cache-Tag: paper:` on unversioned requests | ```bash curl -O https://arxivv.org/1706.03762v7/assets/Figures/ModalNet-21.png ``` ## Versions | URL | Serves | Extra headers | | ------------------ | ------------------ | -------------------------------------------------------------------------- | | `/1706.03762.md` | Latest version | `Link: ; rel="canonical"`, `Cache-Tag: paper:1706.03762` | | `/1706.03762v7.md` | Version 7, forever | None | | `/1706.03762v1.md` | Version 1, forever | None | - Unversioned URLs follow arXiv: they serve the latest known version. - Every response states its version in `X-Arxivv-Version`. - Versioned URLs are immutable. Cite them. - An unknown paper or version is looked up on arXiv (OAI-PMH) on first request. - Old-style IDs work the same way: `/hep-th/9901001.md`, `/hep-th/9901001v1.json`. ### Daily harvest | Property | Value | | -------- | --------------------------------------------------------------------------------------------------- | | Schedule | Daily at 03:00 UTC | | Source | arXiv OAI-PMH `ListRecords` (`arXivRaw`) for the previous day | | Effect | Updates latest-version pointers and metadata | | Purge | When a known paper gains a version, unversioned responses tagged `paper:` are purged from cache | | Builds | The new version is built on its first request, not by the harvest | ## Caching | Response | `Cache-Control` | | ------------------------------------------------------------------------------------------ | ---------------------------------------------------- | | Versioned URL | `public, max-age=31536000, immutable` | | Unversioned URL | `public, max-age=3600, stale-while-revalidate=86400` | | `.json`, `outline.json` or `metadata.json` while inferred fields are `pending` or `failed` | `public, max-age=30` | | `metadata.json` before the tree is built | `public, max-age=30` | | A `Prefer` preference was applied | `no-store` | | Errors | `no-store` | Assets follow the URL rule: versioned asset URLs are immutable, unversioned ones (`/1706.03762/assets/...`) use the unversioned policy and carry `Cache-Tag`. `//metadata.json` never triggers a build and ignores `Prefer`, so it is never `no-store`. Once the tree is built and inferred fields are `ready`, it follows the URL rule like any other route. Precedence: `no-store` first, then pending or failed, then the URL rule. Every paper response carries `Vary: Prefer`. ## Response headers Every arXivv paper response carries these headers: | Header | Example | Meaning | | ------------------ | ------------------------------------- | --------------------------------------------------------------------- | | `X-Arxivv-Schema` | `1` | Major [schema version](/json#compatibility) | | `X-Arxivv-Version` | `7` | arXiv version served | | `X-Arxivv-Quality` | `0.97` | Conversion [quality score](/document-model#quality-score) | | `X-Arxivv-Source` | `arxiv-html` | Where the tree was built from | | `Vary` | `Prefer` | Responses differ by `Prefer` | | `Cache-Control` | See [caching](#caching) | | | `Link` | `; rel="canonical"` | Unversioned requests only | | `Cache-Tag` | `paper:1706.03762` | Unversioned requests only (assets too); used to purge on new versions | `X-Arxivv-Quality` and `X-Arxivv-Source` are absent from `202` responses and from `metadata.json` for an unbuilt paper, since no tree exists yet. See [first request](/first-request) for `Preference-Applied`, `Retry-After` and `Location`.