If you run a bitcoin meetup, this is for you:
Meetup.Com backup/replacement using nostr also pulls in events on existing meetup page (external link to @Derek Ross's Plektos) https://kcbitcoiners.com/calendar
Embeded/Private @npub15guz...twuk add locations using nostr.
https://kcbitcoiners.com/shop
This is a static website hosted on s3 so even non technical folks could deploy it super easily. If anyone finds this useful, I could fork it and make a generalized version for any meetup/group. There is a simple whitelist of npubs in the code for who can add events or locations.
)
```mermaid
erDiagram
ATTESTOR ||--o{ ATTESTATION_EVENT : signs
ASSERTOR ||--o{ ASSERTION_EVENT : signs
ATTESTATION_EVENT ||--|| ASSERTION_EVENT : attests_to
```
---
## Extended Definitions
| Entity | Definition |
| ---------------------------------------- | -------------------------------------------------------------------------------------------- |
| `Requestor` | Signer of the `Attestation Request Event`. |
| `Reccomender` | Signer of the `Attestation Recommendation Event`. |
| `Attestation Request Event` | The request for an `Attestation Event` from an `Attestor`. |
| `Attestor Recommendation Event` | The recommendation of a given `Attestor` for proficiency in the verification of given kinds. |
| `Attestor Proficiency Declaration Event` | A declaration of proficiency from a given `Attestor` in the verification of given kinds. |
)
```mermaid
erDiagram
ATTESTOR o|--o{ ATTESTATION_EVENT : signs
ATTESTOR o|--|| ATTESTOR_PROFICIENCY_DECLARATION_EVENT : signs
ASSERTOR o|--o{ ASSERTION_EVENT : signs
ASSERTOR o|--o{ ATTESTATION_REQUEST_EVENT : signs
REQUESTOR o|--o{ ATTESTATION_REQUEST_EVENT : signs
RECOMMENDER o|--o{ ATTESTOR_RECOMMENDATION_EVENT : signs
ATTESTATION_EVENT ||--|| ASSERTION_EVENT : attests_to
ATTESTATION_REQUEST_EVENT ||--|| ASSERTION_EVENT : requests_attestation_of
ATTESTOR_RECOMMENDATION_EVENT ||--|| ATTESTOR: recommends
ATTESTOR_PROFICIENCY_DECLARATION_EVENT ||--|| ATTESTOR: declares_proficiency_of
```
---
# Specification
### Event Kinds
| Kind | Description | Type |
| ------- | -------------------------------- | ----------- |
| `31871` | Attestation | Addressable |
| `31872` | Attestation Request | Addressable |
| `31873` | Attestor Recommendation | Addressable |
| `11871` | Attestor Proficiency Declaration | Replaceable |
---
## Tags
### Attestation Event (`31871`)
Event signed by the `Attestor`. The `Attestor` should only sign an `Attestation Event` after verifying the validity of the `Assertion Event` to a degree appropriate for its kind type.
| Tag | Description | Format | Required |
| ------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------- | ----------- |
| `d` | Unique identifier for addressable attestation. | `["d", "<npub>:my-claim-id"]` | Yes |
| `e` / `a` / `p` | Specific `Assertion Event`. Exactly one of `e` or `a` or `p` **must** be present. | `["e", "<event-id>"]` or `["a", "<kind>:<pubkey>:<d-tag>"]` or `["p", <pubkey>]` | Yes |
| `v` | Validity claim. Conditional on `s` = `verified` | `["v", "valid"]` or `["v", "invalid"]` | Conditional |
| `s` | Marks an Attestation as being in only one of the following states:`accepted`- `rejected` - `verifying` - `verified` - `revoked` | `["s","accepted <> rejected <> verifying <> verified <> revoked"]` | Optional |
| `valid_from` | Unix timestamp (seconds). The earliest time (inclusive) at which the attestation is valid from. Clients **should** interpret the absence of `valid_from` tag as having `validity`/`invalidity` from the `created_at` timestamp of the `Assertion Event` | `["valid_from",1671217411]` | Optional |
| `valid_to` | UNIX timestamp (seconds). The latest time (inclusive) at which the attestation is valid from. Clients **should** interpret the absence of `valid_to` tag as having `validity`/`invalidity` in perpetuity. | `["valid_from",1671567643]` | Optional |
| `expiration` | UNIX timestamp (seconds). The time (inclusive) at which the `Attestation Event` will expire and be treated as such by relays in accordance to `NIP-40`. Clients **should** set this it be the same value as `valid_to` if there is no value in the `Attestation Event` being long-lived. | `["expiration",1671567643]` | Optional |
| `request` | `Attestation Request Event` that prompted this attestation. | `["request", "31872:<requestor_pubkey>:<d-tag>"]` | Optional |
---
### Attestation Request (`31872`)
Event signed by the `Requestor` (usually the `Assertor`) requesting an `Attestation Event` from an `Attestor`.
| Tag | Description | Format | Required |
| ------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------- | -------- |
| `d` | Unique identifier for addressable attestation request. | `["d", "<requestor_pubkey>:my-request-id"]` | Yes |
| `e`/`a`/`p` | Specific `Assertion Event` Exactly one of `e` or `a` or `p` must be present. | `["e", "<event-id>"]` or `["a", "<kind>:<pubkey>:<d-tag>"]` or `["p", <pubkey>]`.| Yes |
| `p` | One or more requested `Attestators` | `["p", "<attestor_pubkey>"]` | No |
| `cashu_token` | A Cashu token locked to given spending conditions (HLTC, P2PK, etc.). Spending conditions *may* be locked to the observation of requested `Attestation Events`. | `["cashu_token", "<cashuBo...>"]` | No |
---
### Attestor Recommendation (`31873`)
Event signed by the `Recommender`.
Allows any npub to recommend an `Attestor` for verification proficiency in one or more event kinds.
| Tag | Description | Format | Required |
| ------ | ---------------------------------------------------------------- | ------------------------------------------------ | -------- |
| `d` | Unique identifier for the recommendation of a given`Attestor`. | `["d", "<attestor_pubkey>` | Yes |
| `k` | One or more event kinds the attestor is recommended for | `["k", "<kind>"]` (repeatable) | Yes |
| `desc` | Optional human-readable reason or context for the recommendation | `["desc", "Trustworthy for place attestations"]` | No |
---
### Attestor Proficiency Declaration (`11871`)
Event signed by the `Attestor`.
Enables an attestor to publicly declare which event kinds they are proficient in verifying; facilitating discovery of suitable attestors for specific verification needs.
| Tag | Description | Format | Required |
| ------ | ----------------------------------------------------------------- | -------------------------------------------- | -------- |
| `p` | Attestor’s pubkey (the declaring party) | `["p", "<pubkey>"]` | Yes |
| `k` | One or more event kinds the attestor claims proficiency in | `["k", "<kind>"]` | Yes |
| `desc` | Optional human-readable description of proficiency or credentials | `["desc", "I verify places and attributes"]` | No |
---
# Worked Examples
## 1. Attestation Request
```
{
"kind": 31872,
"tags": [
["d", "npub1requestor...:my-request-id"],
["a", 12345:npub1...:central-park-saftey-assertation"],
["p", "npub1attestor1..."]
["p", "npub1attestor2..."]
],
"content": "Verify safety status for Central Park"
}
```
## 2. Attestation
```
{
"kind": 31871,
"tags": [
["d", "npub:safety-verification-2025"],
["a", "12345:npub1...:central-park-saftey-assertation"],
["validity", "valid"],
["valid_from", "1760227200"], // Sept 12, 2025 @ 00:00 UTC
["valid_to", "1760486400"], // Sept 15, 2025 @ 00:00 UTC
["request", "request-event-id-123"]
],
"content": "Safety inspection valid"
}
```
## 3. Revocation
```
{
"kind": 31871,
"tags": [
["d", "npub:safety-verification-2025"],
["s", "revoked"]
],
"content": "Retracted due to new safety concerns"
}
```
---
# Related NIPs
## NIP-03 - OpenTimeStamps Attestations
An `Attestor`, `Assertor` or any other npub may choose to issue a `kind:1040` `OpenTimestamps Attestations for Events` event to anchor the `Attestation Event` to a given blockheight on the Bitcoin timechain.
## NIP-58 - Badges
An `Attestor` or any other npub may choose to issue a badge for a given `Attestation` should they wish.
Users and clients would need to weigh Attestations in accordance to their social graph and preferences using WoT. e.g. people may highly weight Proof of Place Attestations from BTC Map, but not music recommendations.
More context here:
