> For a complete page index of the Captain API documentation, fetch https://docs.captain.dev/llms.txt?excludeSpec=true # Supported File Types > Every file type and extension Captain indexes, grouped by category. ## Agent Quick Reference - Supported File Types 186 extensions in seven categories. Documents (3): pdf, docx, doc. Sheets (4): xlsx, xls, csv, tsv. Images (7): png, jpg, jpeg, gif, bmp, tiff, webp. Audio (7): mp3, wav, m4a, ogg, flac, aac, wma. Video (7): mp4, mov, avi, mkv, webm, flv, wmv. Email (2): msg, eml. An email becomes one text document for the message and one document per attachment, linked by relations. Text and code (156): txt, md, json, yaml, yml, py, pyi, pyw, ipynb, js, mjs, cjs, jsx, ts, tsx, mts, cts, coffee, java, kt, kts, scala, sbt, groovy, gradle, clj, cljs, edn, c, h, cpp, cc, cxx, hpp, hxx, hh, m, mm, cs, csx, fs, fsx, razor, cshtml, go, rs, rb, erb, rake, gemspec, php, phtml, swift, pl, pm, lua, r, rmd, dart, jl, nim, zig, ex, exs, erl, hrl, hs, elm, ml, mli, s, asm, vbs, applescript, sql, ddl, sh, bash, zsh, fish, ksh, csh, tcsh, ps1, psm1, psd1, bat, cmd, html, htm, xhtml, shtml, css, scss, sass, less, styl, vue, svelte, astro, hbs, ejs, pug, twig, liquid, njk, mustache, markdown, mdown, mdx, rst, adoc, asciidoc, org, tex, bib, textile, text, diff, patch, toml, ini, cfg, conf, properties, lock, tf, tfvars, hcl, nix, cmake, mk, bzl, bazel, dockerfile, log, json5, jsonc, jsonl, ndjson, geojson, graphql, gql, proto, xml, xsl, xslt, xsd, dtd, rss, atom, xaml, svg, drawio, csproj, sln. Text and code files are indexed as plain text (no syntax parsing). Extensionless files from cloud storage connectors are content-sniffed and indexed when the content is a supported type. Compiled or binary variants (pyc, class, o, so, dll, wasm, jar, svgz), plist, and secret-bearing files (env, pem, key, crt) are not indexed. See [File Size Limits](/guides/file-size-limits) for the per-type size ceilings. Captain indexes the 186 file types below, sent through a direct upload, the dashboard, raw text, or a cloud storage connector. Each one is parsed, chunked, and embedded for search. | Category | Count | Extensions | | ------------- | ----- | ----------------------------------------------------------------------------------------------------------------------- | | Documents | 3 | `pdf`, `docx`, `doc` | | Sheets | 4 | `xlsx`, `xls`, `csv`, `tsv` | | Images | 7 | `png`, `jpg`, `jpeg`, `gif`, `bmp`, `tiff`, `webp` | | Audio | 7 | `mp3`, `wav`, `m4a`, `ogg`, `flac`, `aac`, `wma` | | Video | 7 | `mp4`, `mov`, `avi`, `mkv`, `webm`, `flv`, `wmv` | | Email | 2 | `msg`, `eml` | | Text and code | 156 | `txt`, `md`, `json`, `yaml`, and 151 source, markup, and config extensions listed under [Text and code](#text-and-code) | ## Documents How the document lane works, with citations and the two processing tiers: [Documents](/guides/file-types/documents). | Extension | Type | What you get | | --------------- | ---- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `.pdf` | PDF | Text chunks labeled by layout role (`body`, `table`, `heading`, `figure`, and more), each with a page range. See [Advanced Search & Relations](/guides/advanced-querying). | | `.docx`, `.doc` | Word | Text chunks with a page range (`metadata.pageStart`/`pageEnd`). | ## Sheets How workbooks become row bands with provenance: [Sheets](/guides/file-types/sheets). | Extension | Type | What you get | | --------------- | ------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `.xlsx`, `.xls` | Excel | Structure-aware chunks with row/column provenance (`sheetName`, `rowStart`/`rowEnd`, `colStart`/`colEnd`, `columns`). See [Multimodal Search](/guides/multimodal-search). | | `.csv`, `.tsv` | Tabular text | Same row/column provenance as Excel. | ## Text and code Chunking, JSON parsing scripts and the raw text route: [Text and Code](/guides/file-types/text-and-code). Every extension in this section is read as plain text and split into text chunks with a page range. There is no syntax-aware parsing: a `.py` file and a `.txt` file go through the same lane. For `.json` files, pass a `parsing_script` to control chunking. | Family | Extensions | | --------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Plain text and data | `.txt`, `.md`, `.json`, `.yaml`, `.yml` | | Python | `.py`, `.pyi`, `.pyw`, `.ipynb` | | JavaScript and TypeScript | `.js`, `.mjs`, `.cjs`, `.jsx`, `.ts`, `.tsx`, `.mts`, `.cts`, `.coffee` | | JVM | `.java`, `.kt`, `.kts`, `.scala`, `.sbt`, `.groovy`, `.gradle`, `.clj`, `.cljs`, `.edn` | | C family | `.c`, `.h`, `.cpp`, `.cc`, `.cxx`, `.hpp`, `.hxx`, `.hh`, `.m`, `.mm` | | .NET | `.cs`, `.csx`, `.fs`, `.fsx`, `.razor`, `.cshtml` | | Other languages | `.go`, `.rs`, `.rb`, `.erb`, `.rake`, `.gemspec`, `.php`, `.phtml`, `.swift`, `.pl`, `.pm`, `.lua`, `.r`, `.rmd`, `.dart`, `.jl`, `.nim`, `.zig`, `.ex`, `.exs`, `.erl`, `.hrl`, `.hs`, `.elm`, `.ml`, `.mli`, `.s`, `.asm`, `.vbs`, `.applescript` | | SQL | `.sql`, `.ddl` | | Shell and scripts | `.sh`, `.bash`, `.zsh`, `.fish`, `.ksh`, `.csh`, `.tcsh`, `.ps1`, `.psm1`, `.psd1`, `.bat`, `.cmd` | | Web, markup, and templates | `.html`, `.htm`, `.xhtml`, `.shtml`, `.css`, `.scss`, `.sass`, `.less`, `.styl`, `.vue`, `.svelte`, `.astro`, `.hbs`, `.ejs`, `.pug`, `.twig`, `.liquid`, `.njk`, `.mustache` | | Markdown and docs | `.markdown`, `.mdown`, `.mdx`, `.rst`, `.adoc`, `.asciidoc`, `.org`, `.tex`, `.bib`, `.textile`, `.text`, `.diff`, `.patch` | | Config and infra | `.toml`, `.ini`, `.cfg`, `.conf`, `.properties`, `.lock`, `.tf`, `.tfvars`, `.hcl`, `.nix`, `.cmake`, `.mk`, `.bzl`, `.bazel`, `.dockerfile`, `.log` | | JSON variants and data text | `.json5`, `.jsonc`, `.jsonl`, `.ndjson`, `.geojson`, `.graphql`, `.gql`, `.proto` | | XML family | `.xml`, `.xsl`, `.xslt`, `.xsd`, `.dtd`, `.rss`, `.atom`, `.xaml`, `.svg`, `.drawio`, `.csproj`, `.sln` | Not indexed, by design: compiled or binary variants (`.pyc`, `.pyo`, `.class`, `.o`, `.so`, `.dll`, `.wasm`, `.jar`, `.svgz`), `.plist` (often binary), and secret-bearing files (`.env`, `.pem`, `.key`, `.crt`). Files with no extension arriving through a cloud storage connector are not rejected up front. The indexer sniffs their content type (HTTP content type plus magic bytes) and indexes them when the content is a supported type. ## Images What an image becomes and how `mask_pii` treats it: [Images](/guides/file-types/images). | Extension | Type | What you get | | --------------------------------------------------------- | ------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `.png`, `.jpg`, `.jpeg`, `.gif`, `.bmp`, `.tiff`, `.webp` | Raster images | One chunk per image: a native embedding of the pixels plus a written description stored as searchable text, so a query matches what the image shows, not just its filename. | Images are supported up to 200 megapixels decoded, and can run through `mask_pii` for OCR-based redaction. See [PII Masking](/guides/pii-masking). ## Video Clips, transcripts and descriptions: [Video](/guides/file-types/video). | Extension | Type | What you get | | ------------------------------------------------------- | ----- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `.mp4`, `.mov`, `.avi`, `.mkv`, `.webm`, `.flv`, `.wmv` | Video | Segmented into clips up to 120s. Each clip has a native embedding plus a transcript and a visual description stored as searchable text. Segment time range in `metadata.startSec`/`endSec`. | ## Audio Clips and transcripts for audio files: [Audio](/guides/file-types/audio). | Extension | Type | What you get | | ------------------------------------------------------- | ----- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `.mp3`, `.wav`, `.aac`, `.flac`, `.m4a`, `.ogg`, `.wma` | Audio | Segmented into clips up to 80s. Each clip has a native embedding plus a transcript and a description stored as searchable text. Segment time range in `metadata.startSec`/`endSec`. | Video and audio detail, including transcript language control, lives on [Multimodal Search](/guides/multimodal-search). ## Email Parts, relations and metadata in full: [Email](/guides/file-types/email). | Extension | Type | What you get | | -------------- | ------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `.msg`, `.eml` | Outlook / RFC 822 message | The message body as a text document plus one document per attachment, each parsed as its own type. `email_attachment` relations link the body to its attachments and `email_reply_to` links a reply to its parent, in both directions. See [Advanced Search & Relations](/guides/advanced-querying). | Every part carries these filterable metadata keys (empty string when the header is absent): | Key | On | Value | | ----------------------------------------------- | ----------- | ----------------------------------------------------------------------- | | `email_role` | all | `body` or `attachment` | | `email_message_id`, `email_in_reply_to` | all / body | `Message-ID` without angle brackets | | `email_thread_id` | all | `Message-ID` at the root of the reply chain, shared by the whole thread | | `email_from`, `email_subject`, `email_date` | all | Headers as sent; date as ISO 8601 UTC | | `email_source_uri` | all | The email file's own URI (`s3://…`, `gs://…`, blob URL, `dropbox://…`) | | `email_parent_identity` | attachments | The body's identity, `msg://` | | `email_attachment_name`, `email_content_sha256` | attachments | File name; SHA-256 of the bytes | | `email_attachment_count` | body | Attachments indexed from the message | Not indexed: inline signature images, empty or duplicate attachments, and unsupported types. Re-indexing an email replaces its parts in place and removes attachments no longer present. ```json { "query": "unit price", "filter": { "email_thread_id": { "$eq": "quote-2026-09-01@example.com" } } } ``` ## Size limits by type Each type has its own per-file and per-request ceiling, and the ceiling also depends on how the file reaches Captain (dashboard, API, or a connector). See [File Size Limits](/guides/file-size-limits) for the full breakdown.