Educational Data Pool — integration guide

1. What is stored kind 30142

Each educational resource is stored as a Nostr addressable event of kind 30142, implementing the Allgemeines Metadatenprofil für Bildungsressourcen (AMB). An event is uniquely identified by its three-part coordinate kind:pubkey:d-tag — the d tag typically holds the canonical resource URL. Metadata is stored as flat Nostr tags using : as a nesting delimiter. The exact on-the-wire mapping — which AMB property becomes which Nostr tag — is defined in NIP-AMB, the specification that defines kind 30142. "Kind 30142" and "NIP-AMB" always refer to the same event format — the number is what goes over the wire, NIP-AMB is the document that specifies it.

What "addressable" means. Nostr defines four event-storage behaviours by kind range (NIP-01): regular events are kept indefinitely, replaceable events (kind 10000–19999) keep only the latest per (kind, pubkey), and addressable events (kind 30000–39999, sometimes called parameterized replaceable) keep only the latest per (kind, pubkey, d-tag). Because the resource carries its own d identifier, one author can hold arbitrarily many distinct kind 30142 resources, each independently replaceable in place — publishing the same coordinate again overwrites the prior version rather than appending a duplicate. That stable coordinate is what makes a resource referenceable: other events point at it with an a tag ("a", "30142:<pubkey>:<d-tag>") and it can be encoded as an NIP-19 naddr for sharing. See the NIP-01 "Kinds" section for the authoritative range definitions.

Extension namespaces — properties outside the AMB-core spec use an ext prefix so they coexist without collision:

• ext:ekw:<facet>:<sub> — EKW vocabulary (e.g. ext:ekw:gradeLevel:id, ext:ekw:method:prefLabel:de). <sub> is one of id, type, prefLabel:<lang>, name. Free-text facets (ext:ekw:methodOther, ext:ekw:bibleReference) are bare key/value tags with no :sub suffix. The full facet list and their vocabularies are in Section 5.
• ext:<d-slug>:<facet>:<sub> — per-community metadata form fields where <d-slug> is the d-tag of the kind 30168 form (colon-free). The form event itself is referenced via ["a", "30168:<pub>:<d>", <relay>, "form"].

2. How data enters the pool

Kind 30142 events are produced by any Nostr client that can sign on behalf of the author — whether it holds the private key directly or delegates to a remote signer (NIP-46). Signing is independent of where the event is published:

• Edufeed resource form — a guided wizard in the Edufeed web app that maps form fields to the AMB tag structure and signs the event client-side via NIP-07 (browser extension) or NIP-46 (remote signer).
• EKW wizard — a community-specific form with EKW vocabulary fields (ext:ekw:*).
• Sitemap / pipeline import — automated tools fetch OER catalogue sitemaps, convert each record to a kind 30142 event, and publish in bulk to the AMB relay.

After signing, the event is published to the Edufeed AMB relay (wss://amb-relay.edufeed.org) using standard Nostr EVENT messages. Anyone who can sign as the author can later publish replacements or deletions for the same coordinate.

For a quick end-to-end check from the command line, nak (the Nostr army knife) builds, signs, and publishes a valid kind 30142 event in one call:

# Build, sign, and publish a kind 30142 event to the AMB relay
nak event -k 30142 \
  -d "https://example.org/my-resource" \
  -t "name=My Open Educational Resource" \
  -t "about:id=http://w3id.org/kim/schulfaecher/s1055" \
  -t "about:prefLabel:de=Religion" \
  -t "learningResourceType:id=https://w3id.org/kim/hcrt/drill_and_practice" \
  -t "learningResourceType:prefLabel:de=Übung" \
  -t "t=Beispiel" \
  -c "A short description of the resource." \
  --sec nsec1... \
  wss://amb-relay.edufeed.org

3. Does storage location matter?

No — the canonical address of a resource is its coordinate 30142:<pubkey>:<d-tag>, which is location-independent. The same signed event can be stored on any number of relays simultaneously. The Edufeed AMB relay (wss://amb-relay.edufeed.org) is the primary index, but clients are free to mirror or query elsewhere.

Query using standard NIP-01 filters:

// All AMB events (up to relay limit)
{"kinds": [30142]}

// Specific resource by coordinate
{"kinds": [30142], "authors": ["<pubkey-hex>"], "#d": ["<d-tag-value>"]}

// Filter by Nostr-native keyword tag
{"kinds": [30142], "#t": ["Gerechtigkeit"]}

// Filter by subject URI (AMB tag filter)
{"kinds": [30142], "#about:id": ["http://w3id.org/kim/schulfaecher/s1055"]}

// Filter by resource type URI
{"kinds": [30142], "#learningResourceType:id": ["https://w3id.org/kim/hcrt/drill_and_practice"]}

Tag filters only work for keys the relay indexes: all single-letter Nostr tags (d, t, p, a, …) plus the AMB-core keys such as about:id and learningResourceType:id. Values must match byte-for-byte (note the http:// scheme above — it is whatever the producer stored, not necessarily https://). Extension namespaces (ext:ekw:* and per-form ext:<slug>:*) are not indexed for filtering; fetch a coarser set and refine client-side, or use the converter to read them out of the ext object.

Query using NIP-50 full-text search (supported by amb-relay.edufeed.org):

// Free-text search across name, description, keywords
{"kinds": [30142], "search": "evangelisch"}

// Field-specific filter via dot-notation
{"kinds": [30142], "search": "publisher.name:e-teaching.org"}

// Combined: free text + field filter
{"kinds": [30142], "search": "Frieden about.prefLabel.de:evangelisch"}

NIP-50 dot-notation covers AMB-core fields (name, description, publisher.name, about.prefLabel.<lang>, …). Like the tag index, it does not currently reach ext.* facets.

Query from the command line with nak:

# All AMB events, newest first (limit 20)
nak req -k 30142 -l 20 wss://amb-relay.edufeed.org

# Filter by subject tag
nak req -k 30142 -t about:id=http://w3id.org/kim/schulfaecher/s1055 wss://amb-relay.edufeed.org

# NIP-50 full-text search
nak req -k 30142 --search "evangelisch" wss://amb-relay.edufeed.org

4. How events are updated or deleted

Kind 30142 is an addressable (parameterized replaceable) event. When a client publishes a new event with the same (kind, pubkey, d-tag) triple, relays keep only the newest created_at; older versions are superseded automatically. There is no explicit "patch" step — the author simply re-publishes the full updated event.

Deletion uses NIP-09 (kind 5): the author publishes a deletion event referencing the addressable coordinate as an a tag:

// NIP-09 deletion event
{
  "kind": 5,
  "tags": [
    ["a", "30142:<pubkey>:<d-tag-value>", "<relay-hint>"]
  ],
  "content": "Resource removed"
}

Relays that honour NIP-09 will stop serving the referenced event. Clients that implement deletion-aware models will filter it from results automatically.

5. Categorisation and controlled vocabularies

Classification uses SKOS-aligned controlled vocabularies. Every concept carries its vocabulary URI (:id), a human-readable label (:prefLabel:<lang>), and the type marker (:type = "Concept"). Multiple concepts in the same field are stored as repeated tag groups (boundary on repeated :id).

EKW extension vocabularies

The EKW profile — named for the Evangelische Kirche von Kurhessen-Waldeck (EKKW) — adds domain-specific facets under the ext:ekw:* namespace, plus three EKW-specific replacements for AMB-core vocabularies. All of these vocabularies are published as Nostr concept schemes (kind 39737, individual concepts kind 39738) by VocabulOER (npub16f5fut6…) and are browsable on Edufeed's vocabulary tool, nocabs.edufeed.org. Concept :id values on EKW events are therefore Nostr-native coordinates (nostr:39738:<vocab-pubkey>:<concept-d>), not HTTP URIs.

Per-community metadata forms add further namespaces under ext:<form-d-slug>:* (kind 30168 forms), referenced from the resource via ["a", "30168:<pub>:<d>", <relay>, "form"].

6. Convert events back to plain JSON (AMB)

The amb-nostr-converter library (the same tool powering the widget below) can reconstruct an AMB JSON document from any kind 30142 event. It reverses the tag-flattening, re-groups concept arrays, maps p tags to creator/contributor, maps a tags to relation objects, and surfaces ext:* tags under a sibling ext object in the output.

Install it from the Edufeed npm registry and use the CLI (requires Node.js):

npm install amb-nostr-converter --registry=https://git.edufeed.org/api/packages/edufeed/npm/
amb-convert nostr:amb event.json

Or use the live widget below: pick a sample event — or one of the live EKW resources fetched in Section 7 — from the dropdown, and it loads into the left pane and converts automatically. Edit the JSON and click Nostr → AMB to re-run, or AMB → Nostr to go the other way.

Fetch a specific event from wss://amb-relay.edufeed.org and load it into the converter above. Accepts a 64-character hex event id, an addressable coordinate kind:pubkey:d-tag, or a NIP-19 naddr, nevent, or note identifier (with or without a nostr: prefix).

7. Live: EKW resources from the relay kind 30142

The cards below are fetched live from wss://amb-relay.edufeed.org at page load — a direct Nostr REQ for kind 30142 events authored by the EKW publisher (npub1wak8hljj…), the same query any client would use. Each card shows the resource title, description, and the ext:ekw:* facets it carries.

8. Client libraries by language

Everything in this guide is plain Nostr, so any Nostr library can read, write, and query kind 30142 events — no Edufeed-specific SDK is required. A few well-maintained options per language:

A broader, continuously updated catalogue of libraries and tools lives in awesome-nostr.