diff --git a/11.md b/11.md index 8cdb85e..a8386ba 100644 --- a/11.md +++ b/11.md @@ -56,3 +56,200 @@ The relay server implementation MAY be provided in the `software` attribute. If ### Version ### The relay MAY choose to publish its software version as a string attribute. The string format is defined by the relay implementation. It is recommended this be a version number or commit identifier. + +Extra Fields +----------------- + +### Server Limitations ### + +These are limitations imposed by the relay on clients. Your client +should expect that requests which exceed these *practical* limitations +are rejected or fail immediately. + +```json +{ +... + limitation: { + max_message_length: 16384, + max_subscriptions: 20, + max_filters: 100, + max_limit: 5000, + max_subid_length: 100, + min_prefix: 4, + max_event_tags: 100, + max_content_length: 8196, + min_pow_difficulty: 30, + auth_required: true, + payment_required: true, + } +... +} +``` + +- `max_message_length`: this is the maximum number of bytes for incoming JSON that the relay +will attempt to decode and act upon. When you send large subscriptions, you will be +limited by this value. It also effectively limits the maximum size of any event. Value is +calculated from `[` to `]` and is after UTF-8 serialization (so some unicode characters +will cost 2-3 bytes). It is equal to the maximum size of the WebSocket message frame. + +- `max_subscriptions`: total number of subscriptions that may be +active on a single websocket connection to this relay. It's possible +that authenticated clients with a (paid) relationship to the relay +may have higher limits. + +- `max_filters`: maximum number of filter values in each subscription. +Must be one or higher. + +- `max_subid_length`: maximum length of subscription id as a string. + +- `min_prefix`: for `authors` and `ids` filters which are to match against +a hex prefix, you must provide at least this many hex digits in the prefix. + +- `max_limit`: the relay server will clamp each filter's `limit` value to this number. +This means the client won't be able to get more than this number +of events from a single subscription filter. This clamping is typically done silently +by the relay, but with this number, you can know that there are additional results +if you narrowed your filter's time range or other parameters. + +- `max_event_tags`: in any event, this is the maximum number of elements in the `tags` list. + +- `max_content_length`: maximum number of characters in the `content` +field of any event. This is a count of unicode characters. After +serializing into JSON it may be larger (in bytes), and is still +subject to the `max_message_length`, if defined. + +- `min_pow_difficulty`: new events will require at least this difficulty of PoW, +based on [NIP-13](13.md), or they will be rejected by this server. + +- `auth_required`: this relay requires [NIP-42](42.md) authentication +to happen before a new connection may perform any other action. +Even if set to False, authentication may be required for specific actions. + +- `payment_required`: this relay requires payment before a new connection may perform any action. + +### Event Retention ### + +There may be a cost associated with storing data forever, so relays +may wish to state retention times. The values stated here are defaults +for unauthenticated users and visitors. Paid users would likely have +other policies. + +Retention times are given in seconds, with `null` indicating infinity. +If zero is provided, this means the event will not be stored at +all, and preferably an error will be provided when those are received. + +```json +{ +... + retention: [ + { kinds: [0, 1, [5, 7], [40, 49]], time: 3600 }, + { kinds: [[40000, 49999], time: 100 }, + { kinds: [[30000, 39999], count: 1000 }, + { time: 3600, count: 10000 } + ] +... +} +``` + +`retention` is a list of specifications: each will apply to either all kinds, or +a subset of kinds. Ranges may be specified for the kind field as a tuple of inclusive +start and end values. Events of indicated kind (or all) are then limited to a `count` +and or time period. + +It is possible to effectively blacklist Nostr-based protocols that rely on +a specific `kind` number, by giving a retention time of zero for those `kind` values. +While that is unfortunate, it does allow clients to discover servers that will +support their protocol quickly via a single HTTP fetch. + +There is no need to specify retention times for _ephemeral events_ as defined +in [NIP-16](16.md) since they are not retained. + + +### Content Limitations ### + +Some relays may be governed by the arbitrary laws of a nation state. This +may limit what content can be stored in cleartext on those relays. All +clients are encouraged to use encryption to work around this limitation. + +It is not possible to describe the limitations of each country's laws +and policies which themselves are typically vague and constantly shifting. + +Therefore, this field allows the relay operator to indicate which +country's' laws might end up being enforced on them, and then +indirectly on their users's content. + +Users should be able to avoid relays in countries they don't like, +and/or select relays in more favourable zones. Exposing this +flexibility is up to the client software. + +```json +{ +... + relay_countries: [ 'CA', 'US' ], +... +} +``` + +- `relay_countries`: a list of two-level ISO country codes (ISO 3166-1 alpha-2) whose + laws and policies may affect this relay. `EU` may be used for European Union countries. + +Remember that a relay may be hosted in a country which is not the +country of the legal entities who own the relay, so it's very +likely a number of countries are involved. + + +### Community Preferences ### + +For public text notes at least, a relay may try to foster a +local community. This would encourage users to follow the global +feed on that relay, in addition to their usual individual follows. +To support this goal, relays MAY specify some of the following values. + +```json +{ +... + language_tags: [ 'en', 'en-419' ], + tags: [ 'sfw-only', 'bitcoin-only', 'anime' ], + posting_policy: 'https://example.com/posting-policy.html', +... +} +``` + +- `language_tags` is an ordered list + of [IETF language tags](https://en.wikipedia.org/wiki/IETF_language_tag) indicating + the major languages spoken on the relay. + +- `tags` is a list of limitations on the topics to be discussed. + For example `sfw-only` indicates hat only "Safe For Work" content + is encouraged on this relay. This relies on assumptions of what the + "work" "community" feels "safe" talking about. In time, a common + set of tags may emerge that allow users to find relays that suit + their needs, and client software will be able to parse these tags easily. + The `bitcoin-only` tag indicates that any *altcoin*, *"crypto"* or *blockchain* + comments will be ridiculed without mercy. + +- `posting_policy` is a link to a human-readable page which specifies the + community policies for the relay. In cases where `sfw-only` is True, it's + important to link to a page which gets into the specifics of your posting policy. + +The `description` field should be used to describe your community +goals and values, in brief. The `posting_policy` is for additional +detail and legal terms. Use the `tags` field to signify limitations +on content, or topics to be discussed, which could be machine +processed by appropriate client software. + +### Pay-To-Relay ### + +Relays that require payments may want to expose their fee schedules. + +```json +{ +... + payments_url: "https://my-relay/payments", + fees: { + "admission": [{ amount: 1000000, unit: 'msats' }], + "subscription": [{ amount: 5000000, unit: 'msats', period: 2592000 }], + "publication": [{ kinds: [4], amount: 100, unit: 'msats' }], + }, +... +}