oxml-opc

Read, mutate, and write the Open Packaging Conventions layer used by OOXML files.

Capabilities

ZIP package parts with configurable read limits.
Content type defaults and overrides.
Relationship parsing, target resolution, and mutation.
Main-document discovery, part navigation, and package preservation.
Case-insensitive package identity, atomic save, agile encryption, and XML signature verification cover the container boundary below both facades.

Measured footprint and speed

The archive row is regenerated from the package that carries this README.

Measurement	Value	Version	Platform	Build mode	Input	Command	Statistic	Measured on
Crates.io archive: oxml-opc	110,291 compressed bytes, 445,033 member bytes, 12 members	0.14.2	macOS 26.6.2, Apple M5 Max, arm64	`cargo publish --workspace --dry-run --allow-dirty --locked`	Tracked `oxml-opc` package inventory	`python3 scripts/readme_doctests.py --record-measurements`	gzip archive bytes, tar member bytes, tar member count	2026-10-16

Use it when

Use this crate when implementing an OOXML package reader or writer. Use rdocx or rpptx for complete document APIs.

Relationship

This is the shared successor to the deprecated rdocx-opc shim and is used by both document families. OPC manages containers, parts, and relationships. It does not interpret document-format XML. Encryption and digital signature APIs are optional feature-gated capabilities.

Example

use oxml_opc::ContentTypes;

let content_types = ContentTypes::from_xml(br#"
    <Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types">
      <Default Extension="xml" ContentType="application/xml"/>
    </Types>
"#)?;
assert_eq!(content_types.defaults["xml"], "application/xml");
# Ok::<(), oxml_opc::OpcError>(())