PID

dPID • Persistent Identifiers • Content Adressing

The dPID system for research objects allows resolution to the underlying components in a consistent and granular way over HTTP and the IPFS network. You can learn more about the schema, syntax and variants below. Note that the system is under active development, and the specification is subject to change.

CID refers to Content Identifier according to the Multiformats CID Specification

dPID anatomy

HTTP URL = {Resolver}/{PID}/{version identifier OR CID}/{Component index}/{Component suffix}

Component	Component Description
Resolver	The DNS resolver, currently beta.dpid.org
PID	The registry's unique and version-invariant PID
Version identifier or CID	The version identifier (e.g. "v1" or "0") mapped to the CID of the manifest file or the manifest CID
Component index	The index of the component in the research object's data model, or the component ID
Component suffix	JSONPath to manifest component. Encoded with slashes and compact format for URL friendliness.

Example dPID Links for Data Access

Type	Link
Web	https://beta.dpid.org/46
Metadata	https://beta.dpid.org/46?jsonld and https://beta.dpid.org/46?raw
Past Metadata	https://beta.dpid.org/46/v1?raw
Code	https://beta.dpid.org/46/3/root/exploring-lupus/casa/J15430131-3409153_cont.py?raw
Data	https://beta.dpid.org/46/v4/root/exploring-lupus/output/data_lup.txt?raw

Note: Excluding ?raw results in resolving the human-accessible data in the Nodes App or another configured resolver application.

API for Research Objects

Route	Behavior
GET https://beta.dpid.org/api/v1/dpid	List all registered research objects Query Params page: number = 1 // first page size: number = 100 // 100 items sort: "asc" | "desc" = "desc" // sort descending Response { "dpid": "54", "id": "0x0...", "recentCid": "bafkre...", "researchObject": { "id": "0x0...", "versions": [ { "id": "0x0...", "time": 1685098464, "cid": "bafkre...", }, { "id": "0x0...", "time": 1685098776, "cid": "bafkre...", } ] } }
GET https://beta.dpid.org/46/v1?raw	Get metadata for specific version of specific research object (application format) Response Typescript specification: https://github.com/desci-labs/nodes/blob/develop/desci-models/src/ResearchObject.ts
GET https://beta.dpid.org/46/v1?jsonld	Get metadata for specific version of specific research object (semantic format) Returns in RO-Crate 1.1 format Response Typescript specification: https://github.com/desci-labs/nodes/blob/develop/desci-models/src/RoCrate.ts

Navigating Data via dPID API

Route	Behavior
GET https://beta.dpid.org/46/root?raw GET https://beta.dpid.org/46/v1/root?raw deprecated GET https://beta.dpid.org/46/data?raw GET https://beta.dpid.org/46/v1/data?raw	These all do the same thing. Get the DAG-JSON encoded content of the root data folder. If version specified, uses that version, otherwise uses latest version.
GET https://beta.dpid.org/46/root/exploring-lupus-report.pdf?raw	Download the specific file specified, if not a file, but a folder, the DAG-JSON encoded content is shown

Valid PID syntax and variants

There are three different and valid variants of the PIDs that can be resolved over HTTP. These variants offer different levels of friendliness for humans.

Variant types	Variant syntax (human)	Variant syntax (machine)
Short form URL variant (recommended)	https://beta.dpid.org/46/v4/root/exploring-lupus/output/data_lup.txt	https://beta.dpid.org/46/v4/data/exploring-lupus/output/data_lup.txt?raw
Short form URL variant 0-index⚠️ deprecated	https://beta.dpid.org/46/3/data/exploring-lupus/output/data_lup.txt	https://beta.dpid.org/46/3/data/exploring-lupus/output/data_lup.txt?raw
Long form URL ⚠️ coming soon	dpid.org/42/bafybeigdyrzt5sfp7udm7hu76uh7y26nf3efuylqabf3oclgtqy55fbzdi/1/measurements.csv	dpid.org/42/bafybeigdyrzt5sfp7udm7hu76uh7y26nf3efuylqabf3oclgtqy55fbzdi/1/measurements.csv?raw