NIP-AMB

By Edufeed April 20, 2026

Specifies: kind 30142

NIP-AMB

Abstract

This NIP defines how to handle the metadata profile “Allgemeines Metadatenprofil für Bildungsressourcen“ (AMB) in nostr:

How to convert AMB metadata to an AMB nostr event
How to convert an AMB nostr-event to AMB metadata
How to query for AMB nostr-events in supporting relays

Event Kind

This NIP defines kind:30142 as an AMB Metadata Event. This means this is an addressable event, that can be addressed using kind:pubkey:d-tag.

How to convert AMB metadata to an AMB nostr event

The transformation uses JSON-flattening with : as the delimiter to convert nested AMB metadata structures into flat Nostr tags. Additionally, Nostr-native tag conventions are used where applicable for better interoperability and query efficiency.

Nostr-Native Conventions

This NIP follows Nostr conventions where they align with AMB requirements:

d tag: Used as the unique identifier for the AMB resource (maps to AMB id)
t tags: Used for keywords/topics (instead of flattened keywords tags)
p tags: Used for creator/contributor references when the person has a Nostr identity (pubkey). Format: ["p", <pubkey-hex>, <relay-hint>, <role>] where <role> is "creator" or "contributor". The relay hint is a single suggestion for discovery (per NIP-01 convention); clients SHOULD use NIP-65 for full relay resolution. When a p tag is used for a person, no creator:*/contributor:* flattened tags are emitted for that person — the pubkey IS their identity. Persons without a Nostr identity use the flattened creator:*/contributor:* tag structure instead.
a tags: Used for references to other addressable events on Nostr (including other AMB events), with fallback to flattened URIs for external resources. Format: ["a", "30142:<pubkey>:<d-value>", <relay-hint>, <relationship>]
r tags: Used for external URL references (original source, DOI, related web resources)
content field: SHOULD contain the description text for client compatibility; the description tag is kept for relay queryability

Flattening Rules

Simple properties: Map directly to tag}`
- Nostr: ["name", "Resource Title"]
Nested objects: Flatten using : delimiter
- AMB: {"creator": {"name": "John", "id": "123"}}
- Nostr: ["creator:name", "John"], ["creator:id", "123"]
Arrays: Repeat the same flattened tag key (order is preserved by tag array position)
- AMB: {"keywords": ["Math", "Physics"]}
- Nostr: ["t", "Math"], ["t", "Physics"] (Nostr-native t tag)
Arrays of objects: Repeat flattened keys for each object
- AMB: {"creator": [{"name": "John"}, {"name": "Jane"}]}
- Nostr: ["creator:name", "John"], ["creator:name", "Jane"]
Deep nesting: Continue flattening with additional : delimiters
- AMB: {"creator": {"affiliation": {"name": "MIT"}}}
- Nostr: ["creator:affiliation:name", "MIT"]

Property Mappings

This is how we convert each property of the AMB:

General:

id → ["d", <id>] (special case: use Nostr’s d tag as identifier)
type → ["type", <value>] (repeat for multiple types)
name → ["name", <value>]
description → ["description", <value>] AND "content": <value> (duplicated for client compatibility and relay queryability)
about (array of concept objects) → Repeat for each:
- ["about:id", <uri>]
- ["about:prefLabel:lang", <label>]
- ["about:type", "Concept"]
keywords → ["t", <keyword>] (repeat for each keyword, using Nostr t tag)
inLanguage → ["inLanguage", <languageCode>] (repeat for each language)
image → ["image", <uri>]
trailer (MediaObject) →
- ["trailer:contentUrl", <url>]
- ["trailer:type", <"VideoObject"|"AudioObject">]
- ["trailer:encodingFormat", <format>] (optional)
- ["trailer:contentSize", <bytes>] (optional)
- ["trailer:sha256", <hash>] (optional)
- ["trailer:embedUrl", <url>] (optional)
- ["trailer:bitrate", <kbps>] (optional)

Provenance:

creator (array of Person/Organization objects) → For each creator, use one of the following (never both for the same person):
- Nostr-native (creator has a Nostr pubkey): ["p", <pubkey-hex>, <relay-hint>, "creator"] — no additional creator:* tags for this person. Their name and metadata are resolved from their kind:0 profile.
- External (no Nostr identity):
  - ["creator:id", <uri>] (optional, e.g., ORCID, GND)
  - ["creator:name", <name>]
  - ["creator:type", <"Person"|"Organization">]
  - ["creator:honorificPrefix", <title>] (optional, for persons)
  - ["creator:affiliation:id", <uri>] (optional)
  - ["creator:affiliation:name", <name>] (optional)
  - ["creator:affiliation:type", "Organization"] (optional)
contributor (array of Person/Organization objects) → Same structure as creator, using role "contributor" in the p tag
dateCreated → ["dateCreated", <ISO8601Date>]
datePublished → ["datePublished", <ISO8601Date>]
dateModified → ["dateModified", <ISO8601Date>]
publisher (array of Organization/Person objects) → Repeat for each:
- ["publisher:id", <uri>] (optional)
- ["publisher:name", <name>]
- ["publisher:type", <"Organization"|"Person">]
funder (array of Person/Organization/FundingScheme objects) → Repeat for each:
- ["funder:id", <uri>] (optional)
- ["funder:name", <name>]
- ["funder:type", <"Person"|"Organization"|"FundingScheme">]

Costs and Rights:

isAccessibleForFree → ["isAccessibleForFree", <"true"|"false">]
license (object) →
- ["license:id", <license_uri>]
conditionsOfAccess (Concept object) →
- ["conditionsOfAccess:id", <uri>]
- ["conditionsOfAccess:prefLabel:lang", <label>] (optional)
- ["conditionsOfAccess:type", "Concept"] (optional)

Educational:

learningResourceType (array of Concept objects) → Repeat for each:
- ["learningResourceType:id", <uri>]
- ["learningResourceType:prefLabel:lang", <label>] (optional)
- ["learningResourceType:type", "Concept"] (optional)
audience (array of Concept objects) → Repeat for each:
- ["audience:id", <uri>]
- ["audience:prefLabel:lang", <label>] (optional)
- ["audience:type", "Concept"] (optional)
teaches (array of Concept objects) → Repeat for each:
- ["teaches:id", <uri>]
- ["teaches:prefLabel:lang", <label>] (optional)
assesses (array of Concept objects) → Repeat for each:
- ["assesses:id", <uri>]
- ["assesses:prefLabel:lang", <label>] (optional)
competencyRequired (array of Concept objects) → Repeat for each:
- ["competencyRequired:id", <uri>]
- ["competencyRequired:prefLabel:lang", <label>] (optional)
educationalLevel (array of Concept objects) → Repeat for each:
- ["educationalLevel:id", <uri>]
- ["educationalLevel:prefLabel:lang", <label>] (optional)
- ["educationalLevel:type", "Concept"] (optional)
interactivityType (Concept object) →
- ["interactivityType:id", <uri>]
- ["interactivityType:prefLabel:lang", <label>] (optional)
- ["interactivityType:type", "Concept"] (optional)

Relations:

isBasedOn (array of objects) → Repeat for each:
- Nostr-native (if referenced resource is addressable AMB event): ["a", "30142:<pubkey>:<d-value>", <relay>, "isBasedOn"]
- Fallback (for external URIs):
  - ["isBasedOn:id", <uri>]
  - ["isBasedOn:name", <name>] (optional)
isPartOf (array of objects) → Repeat for each:
- Nostr-native (if referenced resource is addressable AMB event): ["a", "30142:<pubkey>:<d-value>", <relay>, "isPartOf"]
- Fallback (for external URIs):
  - ["isPartOf:id", <uri>]
  - ["isPartOf:name", <name>] (optional)
  - ["isPartOf:type", <type>] (optional)
hasPart (array of objects) → Repeat for each:
- Nostr-native (if referenced resource is addressable AMB event): ["a", "30142:<pubkey>:<d-value>", <relay>, "hasPart"]
- Fallback (for external URIs):
  - ["hasPart:id", <uri>]
  - ["hasPart:name", <name>] (optional)
  - ["hasPart:type", <type>] (optional)

Meta-Metadata:

mainEntityOfPage (array of WebPage objects) → Repeat for each:
- ["mainEntityOfPage:id", <uri>]
- ["mainEntityOfPage:type", "WebContent"]
- ["mainEntityOfPage:provider:id", <uri>] (optional)
- ["mainEntityOfPage:provider:name", <name>] (optional)
- ["mainEntityOfPage:provider:type", <type>] (optional)
- ["mainEntityOfPage:dateCreated", <ISO8601Date>] (optional)
- ["mainEntityOfPage:dateModified", <ISO8601Date>] (optional)

Technical:

duration → ["duration", <ISO8601Duration>] (format: PnYnMnDTnHnMnS)
encoding (array of MediaObject objects) → Repeat for each:
- ["encoding:type", "MediaObject"]
- ["encoding:contentUrl", <url>] (or use embedUrl)
- ["encoding:embedUrl", <url>] (or use contentUrl)
- ["encoding:encodingFormat", <format>] (optional, IANA media type)
- ["encoding:contentSize", <bytes>] (optional)
- ["encoding:sha256", <hash>] (optional)
- ["encoding:bitrate", <kbps>] (optional)
caption (array of MediaObject objects) → Repeat for each:
- ["caption:id", <uri>]
- ["caption:type", "MediaObject"]
- ["caption:encodingFormat", <format>] (optional, IANA media type)
- ["caption:inLanguage", <languageCode>] (optional)

External References:

Supplementary “see also” references use the Nostr-native r tag (per NIP-24). These are Nostr-native metadata for client interoperability and do not map to a specific AMB property on reverse conversion.

["r", <url>] - Repeat for each external reference

Examples:

["r", "https://oersi.org/resources/xyz"] - Original source URL
["r", "https://doi.org/10.1234/example"] - DOI reference
["r", "urn:isbn:978-3-16-148410-0"] - ISBN reference

How to convert an AMB nostr-event to AMB metadata

To convert a Nostr event back to AMB metadata:

Extract tags: Get the tags array from the Nostr event
Group by prefix: Collect all tags that share the same prefix (before the first :)
Reconstruct nesting: Use the : delimiter to rebuild nested object structure
Handle arrays: Multiple tags with identical keys become array elements
Preserve order: Array order is determined by tag order in the event
Special mappings:
- d tag → id property
- content field → description property (prefer over description tag if both exist)
- t tags → keywords array
- r tags → Nostr-native supplementary references (no AMB equivalent; not included in AMB output)
- p tags with role → Nostr-native creator/contributor (see below)
- a tags with role → Nostr-native relation (see below)
- Convert string booleans to actual booleans
- Parse ISO8601 dates if needed for validation
Nostr-native p tags (creator/contributor): For each ["p", <pubkey-hex>, <relay-hint>, <role>] where <role> is "creator" or "contributor", clients MUST fetch the user’s kind:0 profile (using the relay hint and NIP-65) to resolve their name. Map to an AMB creator/contributor object:
```
{
  "name": "<name from kind:0 profile>",
  "id": "nostr:<nprofile1...>"
}
```
The id uses the NIP-19 nprofile encoding (which includes the pubkey and relay hint(s)) prefixed with nostr: per NIP-21. The type ("Person" or "Organization") should be determined from the kind:0 profile if possible; implementations MAY default to "Person" when unknown.
Nostr-native a tags (relations): For each ["a", "30142:<pubkey>:<d-value>", <relay-hint>, <role>] where <role> is "isBasedOn", "isPartOf", or "hasPart", map to the corresponding AMB relation object:
```
{
  "id": "nostr:<naddr1...>",
  "type": "LearningResource"
}
```
The id uses the NIP-19 naddr encoding (which includes kind, pubkey, d-tag, and relay hint(s)) prefixed with nostr: per NIP-21.

How to query for AMB nostr-events in supporting relays

AMB-supporting relays MUST support the standard NIP-01 filter fields and SHOULD support NIP-50 full-text search with field-specific filtering.

Standard Nostr Filters (NIP-01)

Clients can query AMB events using standard Nostr filter fields:

kinds — filter by event kind (always 30142 for AMB events)
authors — filter by pubkey
ids — filter by event ID
#d — filter by the addressable event identifier (d-tag)
since / until — filter by created_at timestamp range

AMB Tag Filters

In addition to standard single-letter tag filters, AMB-supporting relays SHOULD support filtering by the colon-delimited tag names used in AMB events. The tag name in the filter maps directly to the flattened tag key in the event:

Tag Filter	Description
`#t`	Filter by keyword
`#r`	Filter by external reference URL
`#p`	Filter by creator/contributor pubkey
`#a`	Filter by addressable event reference
`#about:id`	Filter by subject (controlled vocabulary URI)
`#learningResourceType:id`	Filter by resource type URI
`#educationalLevel:id`	Filter by educational level URI
`#audience:id`	Filter by target audience URI

Any colon-delimited tag name present in AMB events can be used as a filter. Multiple values for the same tag are matched with OR logic. Different tag filters are combined with AND logic.

NIP-50 Full-Text Search

AMB-supporting relays SHOULD implement NIP-50 to allow full-text search across AMB metadata fields (at minimum: name, description, keywords).

Relays MAY additionally support field-specific search filtering using dot-notation within the search string. The dot-notation maps to the nested AMB field structure (e.g., publisher.name maps to the name subfield of publisher objects):

Field Path	Description
`publisher.name`	Publisher organization name
`creator.name`	Content creator name
`about.prefLabel.<lang>`	Subject/topic label (e.g., `about.prefLabel.de`)
`learningResourceType.prefLabel.<lang>`	Resource type label
`audience.prefLabel.<lang>`	Target audience label
`educationalLevel.prefLabel.<lang>`	Educational level label

Free-text terms and field filters can be mixed in the search string. Multiple values for the same base field are combined with OR logic.

Query Examples

JSON Filter Objects

// All AMB events
{"kinds": [30142]}

// Events by a specific author
{"kinds": [30142], "authors": ["<pubkey-hex>"]}

// Lookup by addressable event coordinate (kind + pubkey + d-tag)
{"kinds": [30142], "authors": ["<pubkey-hex>"], "#d": ["<d-tag-value>"]}

// Events created in a time range
{"kinds": [30142], "since": 1700000000, "until": 1800000000}

// Filter by keyword
{"kinds": [30142], "#t": ["Mathematik"]}

// Filter by subject URI
{"kinds": [30142], "#about:id": ["http://w3id.org/kim/schulfaecher/s1017"]}

// Filter by learning resource type URI
{"kinds": [30142], "#learningResourceType:id": ["http://w3id.org/openeduhub/vocabs/new_lrt/video"]}

// Filter by educational level URI
{"kinds": [30142], "#educationalLevel:id": ["https://w3id.org/kim/educationalLevel/level_06"]}

// Filter by external reference
{"kinds": [30142], "#r": ["https://doi.org/10.1234/example"]}

// Filter by creator/contributor pubkey
{"kinds": [30142], "#p": ["<pubkey-hex>"]}

// Filter by addressable event reference
{"kinds": [30142], "#a": ["30142:<pubkey-hex>:<d-tag-value>"]}

// NIP-50 full-text search
{"kinds": [30142], "search": "pythagorean theorem"}

// NIP-50 search with field-specific filter
{"kinds": [30142], "search": "publisher.name:e-teaching.org"}

// NIP-50 combined: free text + field filter
{"kinds": [30142], "search": "forschung publisher.name:e-teaching.org"}

// NIP-50 multiple values for same field (OR logic)
{"kinds": [30142], "search": "about.prefLabel.de:Mathematik about.prefLabel.de:Physik"}

nak CLI Examples

# All AMB events
nak req -k 30142 ws://relay.example.com

# By author
nak req -a <pubkey-hex> -k 30142 ws://relay.example.com

# By d-tag
nak req -d "oersi.org/resources/example123" -k 30142 ws://relay.example.com

# Time range
nak req --since 1700000000 --until 1800000000 -k 30142 ws://relay.example.com

# By keyword
nak req -t t=Mathematik -k 30142 ws://relay.example.com

# By subject URI
nak req -t about:id=http://w3id.org/kim/schulfaecher/s1017 -k 30142 ws://relay.example.com

# By learning resource type
nak req -t learningResourceType:id=http://w3id.org/openeduhub/vocabs/new_lrt/video -k 30142 ws://relay.example.com

# By external reference
nak req -t r=https://doi.org/10.1234/example -k 30142 ws://relay.example.com

# By creator/contributor pubkey
nak req -p <pubkey-hex> -k 30142 ws://relay.example.com

# Full-text search
nak req --search "pythagorean theorem" -k 30142 ws://relay.example.com

# Field-specific search
nak req --search "publisher.name:e-teaching.org" -k 30142 ws://relay.example.com

# Combined: free text + field filter
nak req --search "forschung publisher.name:e-teaching.org" -k 30142 ws://relay.example.com

Note: Relays that require NIP-42 authentication need --sec <key> --auth flags with nak.

Reference Implementations

amb-relay — Nostr relay specialized for AMB events, built on the khatru relay framework
nostrlib/eventstore/typesense30142 — Typesense-backed eventstore for kind 30142 events with full query documentation in its README

Examples

Example 1: Simple Educational Resource

{
  "kind": 30142,
  "id": "6ba638a3786cfce89af1702a36c59e0bd9206863afa5cb6b1299aaf0d9f48c84",
  "pubkey": "79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798",
  "created_at": 1743419457,
  "tags": [
    ["d", "oersi.org/resources/aHR0cHM6Ly9hdi50aWIuZXUvbWVkaWEvNjY5ODM=11"],
    ["type", "LearningResource"],
    ["name", "Pythagorean Theorem Video"],
    ["description", "An introductory video explaining the Pythagorean theorem"],
    ["about:id", "http://w3id.org/kim/schulfaecher/s1017"],
    ["about:prefLabel:de", "Mathematik"],
    ["about:type", "Concept"],
    ["about:id", "http://w3id.org/kim/schulfaecher/s1005"],
    ["about:prefLabel:de", "Deutsch"],
    ["about:type", "Concept"],
    ["learningResourceType:id", "http://w3id.org/openeduhub/vocabs/new_lrt/7a6e9608-2554-4981-95dc-47ab9ba924de"],
    ["learningResourceType:prefLabel:de", "Video"],
    ["learningResourceType:type", "Concept"],
    ["t", "Pythagoras"],
    ["t", "Geometrie"],
    ["t", "Mathematik"],
    ["inLanguage", "de"],
    ["license:id", "https://creativecommons.org/licenses/by/4.0/"],
    ["isAccessibleForFree", "true"]
  ],
  "content": "An introductory video explaining the Pythagorean theorem",
  "sig": "6b0b78d56dea322864d35ea3b6d7e892d0e62bed96cd11ecb27d6c1d0b6d0cd68cd9ec82419946a5fb3c8d4a21eca88c9a5dad47a3b3e466ba18787224a613ef"
}

Example 2: Resource with Nostr-Native and External Creators

This example demonstrates both creator types: a Nostr-native creator (using a p tag only) and an external creator without a Nostr identity (using creator:* flattened tags).

{
  "kind": 30142,
  "id": "7ca749b4897efdc98fe2803dc60f68c9e1cd29764e8a55d1e9ef47a46ba4fe75",
  "pubkey": "79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798",
  "created_at": 1743419500,
  "tags": [
    ["d", "https://example.org/courses/physics-101"],
    ["type", "LearningResource"],
    ["type", "Course"],
    ["name", "Introduction to Physics"],
    ["description", "A comprehensive introduction to classical mechanics"],
    ["p", "79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798", "wss://relay.example.com", "creator"],
    ["creator:id", "https://orcid.org/0000-0009-8765-4321"],
    ["creator:name", "Prof. John Doe"],
    ["creator:type", "Person"],
    ["creator:honorificPrefix", "Prof."],
    ["creator:affiliation:name", "Stanford University"],
    ["creator:affiliation:type", "Organization"],
    ["dateCreated", "2024-01-15"],
    ["datePublished", "2024-02-01"],
    ["about:id", "https://w3id.org/kim/hochschulfaechersystematik/n079"],
    ["about:prefLabel:de", "Informatik"],
    ["about:type", "Concept"],
    ["learningResourceType:id", "https://w3id.org/kim/hcrt/course"],
    ["learningResourceType:prefLabel:de", "Kurs"],
    ["audience:id", "http://purl.org/dcx/lrmi-vocabs/educationalAudienceRole/student"],
    ["audience:prefLabel:de", "Student"],
    ["audience:type", "Concept"],
    ["educationalLevel:id", "https://w3id.org/kim/educationalLevel/level_06"],
    ["educationalLevel:prefLabel:en", "Bachelor or equivalent"],
    ["inLanguage", "en"],
    ["license:id", "https://creativecommons.org/licenses/by-sa/4.0/"],
    ["isAccessibleForFree", "true"],
    ["r", "https://example.org/courses/physics-101"],
    ["r", "https://doi.org/10.1234/physics-intro"]
  ],
  "content": "A comprehensive introduction to classical mechanics",
  "sig": "8d1c89f5da33ec9a2b456def78a90b1cd23e456f78a90b12cd34e567f89a012b34c56d78e9f0a12bc3d45e6f78901a23b45c67d89e0f1a2b3c4d5e6f7890123a"
}

In this example:

The first creator has a Nostr pubkey, so only a p tag with role "creator" is used. Their name and metadata are resolved from their kind:0 profile.
The second creator (Prof. John Doe) has no Nostr identity, so the creator:* flattened tags provide their name, type, affiliation, and ORCID.

Tools

Using `nak` to create AMB events

You can use nak to create AMB events. There are two approaches:

Flag-based (inline tags)

# Simple resource with Nostr-native t tags
nak event \
  -k 30142 \
  --tag d="oersi.org/resources/example123" \
  --tag type="LearningResource" \
  --tag name="Pythagorean Theorem Video" \
  --tag description="An introductory video" \
  --tag about:id="http://w3id.org/kim/schulfaecher/s1017" \
  --tag about:prefLabel:de="Mathematik" \
  --tag t="Pythagoras" \
  --tag t="Geometrie" \
  --tag inLanguage="de" \
  --tag license:id="https://creativecommons.org/licenses/by/4.0/" \
  --sec <key> --auth ws://relay.example.com

# Resource with Nostr-native creator (p tag)
nak event \
  -k 30142 \
  --tag d="https://example.org/resource/456" \
  --tag name="Physics Course" \
  -p "79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798;wss://relay.example.com;creator" \
  --sec <key> --auth ws://relay.example.com

JSON on stdin (pipe-based)

This approach gives full control over the tag structure and is useful for scripting:

echo '{
  "tags": [
    ["d", "https://example.org/courses/physics-101"],
    ["type", "LearningResource"],
    ["name", "Introduction to Physics"],
    ["description", "A comprehensive introduction to classical mechanics"],
    ["inLanguage", "en"],
    ["t", "physics"],
    ["t", "mechanics"],
    ["creator:name", "Dr. Jane Smith"],
    ["creator:type", "Person"],
    ["license:id", "https://creativecommons.org/licenses/by-sa/4.0/"]
  ],
  "content": "A comprehensive introduction to classical mechanics"
}' | nak event -k 30142 --sec <key> --auth ws://relay.example.com

References

AMB Specification
Nostr Protocol (NIP-01)
Addressable Events (NIP-33)
bech32-encoded entities (NIP-19) - nprofile and naddr encodings for reverse conversion
nostr: URI scheme (NIP-21) - nostr: prefix for bech32 identifiers in AMB output
Extra Metadata Fields and Tags (NIP-24) - r and t tag conventions
Live Activities (NIP-53) - precedent for p tag roles
Relay List Metadata (NIP-65) - relay discovery for p tag relay hints
JSON-Flattening Concept

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NIP-AMB

NIP-AMB

Abstract

Event Kind

How to convert AMB metadata to an AMB nostr event

Nostr-Native Conventions

Flattening Rules

Property Mappings

General:

Provenance:

Costs and Rights:

Educational:

Relations:

Meta-Metadata:

Technical:

External References:

How to convert an AMB nostr-event to AMB metadata

How to query for AMB nostr-events in supporting relays

Standard Nostr Filters (NIP-01)

AMB Tag Filters

NIP-50 Full-Text Search

Query Examples

JSON Filter Objects

nak CLI Examples

Reference Implementations

Examples

Example 1: Simple Educational Resource

Example 2: Resource with Nostr-Native and External Creators

Tools

Using nak to create AMB events

Flag-based (inline tags)

JSON on stdin (pipe-based)

References

Using `nak` to create AMB events