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Merge branch 'overhaul' into 'develop'

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Overhaul

See merge request soapbox-pub/strfry-policies!1
This commit is contained in:
Alex Gleason 2023-03-25 15:18:33 +00:00
commit 75a97095d7
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19
.gitlab-ci.yml Normal file
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image: denoland/deno:1.32.1
default:
interruptible: true
stages:
- test
fmt:
stage: test
script: deno fmt --check
lint:
stage: test
script: deno lint
test:
stage: test
script: deno test

176
README.md
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@ -1,9 +1,183 @@
# strfry policies
A collection of policies for the [strfry](https://github.com/hoytech/strfry) relay, written in Deno.
A collection of policies for the [strfry](https://github.com/hoytech/strfry) Nostr relay, built in Deno.
For more information about installing these policies and how they work, see [Write policy plugins](https://github.com/hoytech/strfry/blob/master/docs/plugins.md).
This library introduces a model for writing policies and composing them in a pipeline. Policies are fully configurable and it's easy to add your own or install more from anywhere on the net.
## Getting started
To get up and running, you will need to install Deno on the same machine as strfry:
```sh
sudo apt install -y unzip
curl -fsSL https://deno.land/x/install/install.sh | sudo DENO_INSTALL=/usr/local sh
```
Create an entrypoint file somewhere and make it executable:
```sh
sudo touch /opt/strfry-policy.ts
sudo chmod +x /opt/strfry-policy.ts
```
Now you can write your policy. Here's a good starting point:
```ts
#!/bin/sh
//bin/true; exec deno run -A "$0" "$@"
import {
antiDuplicationPolicy,
hellthreadPolicy,
pipeline,
rateLimitPolicy,
readStdin,
writeStdout,
} from 'https://gitlab.com/soapbox-pub/strfry-policies/-/blob/develop/mod.ts';
const msg = await readStdin();
const result = await pipeline(msg, [
[hellthreadPolicy, { limit: 100 }],
[antiDuplicationPolicy, { ttl: 60000, minLength: 50 }],
[rateLimitPolicy, { whitelist: ['127.0.0.1'] }],
]);
writeStdout(result);
```
Finally, edit `strfry.conf` and enable the policy:
```diff
writePolicy {
# If non-empty, path to an executable script that implements the writePolicy plugin logic
- plugin = ""
+ plugin = "/opt/strfry-policy.ts"
# Number of seconds to search backwards for lookback events when starting the writePolicy plugin (0 for no lookback)
lookbackSeconds = 0
```
That's it! 🎉 Now you should check strfry logs to ensure everything is working okay.
## Writing your own policies
You can write a policy in TypeScript and host it anywhere. Deno allows importing modules by URL, making it easy to share policies.
Here is a basic sample policy:
```ts
import type { Policy } from 'https://gitlab.com/soapbox-pub/strfry-policies/-/blob/develop/mod.ts';
/** Only American English is allowed. */
const americanPolicy: Policy<void> = (msg) => {
const { content } = msg.event;
const words = [
'armour',
'behaviour',
'colour',
'favourite',
'flavour',
'honour',
'humour',
'rumour',
];
const isBritish = words.some((word) => content.toLowerCase().includes(word));
if (isBritish) {
return {
id: msg.event.id,
action: 'reject',
msg: 'Sorry, only American English is allowed on this server!',
};
} else {
return {
id: msg.event.id,
action: 'accept',
msg: '',
};
}
};
export default americanPolicy;
```
Once you're done, you can either upload the file somewhere online or directly to your server. Then, update your pipeline:
```diff
--- a/strfry-policy.ts
+++ b/strfry-policy.ts
@@ -9,6 +9,7 @@ import {
readStdin,
writeStdout,
} from 'https://gitlab.com/soapbox-pub/strfry-policies/-/blob/develop/mod.ts';
+import { americanPolicy } from 'https://gist.githubusercontent.com/alexgleason/5c2d084434fa0875397f44da198f4352/raw/3d3ce71c7ed9cef726f17c3a102c378b81760a45/american-policy.ts';
const msg = await readStdin();
@@ -17,6 +18,7 @@ const result = await pipeline(msg, [
[hellthreadPolicy, { limit: 100 }],
[antiDuplicationPolicy, { ttl: 60000, minLength: 50 }],
[rateLimitPolicy, { whitelist: ['127.0.0.1'] }],
+ americanPolicy,
]);
writeStdout(result);
```
### Policy options
The `Policy<Opts>` type is a generic that accepts options of any type. With opts, the policy above could be rewritten as:
```diff
--- a/american-policy.ts
+++ b/american-policy.ts
@@ -1,7 +1,11 @@
import type { Policy } from 'https://gitlab.com/soapbox-pub/strfry-policies/-/blob/develop/mod.ts';
+interface American {
+ withGrey?: boolean;
+}
+
/** Only American English is allowed. */
-const americanPolicy: Policy<void> = (msg) => {
+const americanPolicy: Policy<American> = (msg, opts) => {
const { content } = msg.event;
const words = [
@@ -15,6 +19,10 @@
'rumour',
];
+ if (opts?.withGrey) {
+ words.push('grey');
+ }
+
const isBritish = words.some((word) => content.toLowerCase().includes(word));
if (isBritish) {
```
Then, in the pipeline:
```diff
- americanPolicy,
+ [americanPolicy, { withGrey: true }],
```
### Caveats
- You should not use `console.log` anywhere in your policies, as strfry expects stdout to be the strfry output message.
## Available policies
Please look directly at `src/policies` in this repo. The files include detailed JSDoc comments and it has good type support.
![Policies TypeScript](https://gitlab.com/soapbox-pub/strfry-policies/uploads/dfb993b3464af5ed78bb8e5db8677458/Kazam_screencast_00090.webm)
## License
This is free and unencumbered software released into the public domain.

72
anti-duplication-policy.ts
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@ -1,72 +0,0 @@
#!/bin/sh
//bin/true; exec deno run -A "$0" "$@"
import { readLines } from 'https://deno.land/std@0.178.0/io/mod.ts';
import { Keydb } from 'https://deno.land/x/keydb@1.0.0/sqlite.ts';
const ANTI_DUPLICATION_TTL = Number(Deno.env.get('ANTI_DUPLICATION_TTL') || 60000);
const ANTI_DUPLICATION_MIN_LENGTH = Number(Deno.env.get('ANTI_DUPLICATION_MIN_LENGTH') || 50);
interface InputMessage {
type: 'new' | 'lookback';
event: Event;
receivedAt: number;
sourceType: 'IP4' | 'IP6' | 'Import' | 'Stream' | 'Sync';
sourceInfo: string;
}
interface OutputMessage {
id: string;
action: 'accept' | 'reject' | 'shadowReject';
msg: string;
}
interface Event {
id: string;
sig: string;
kind: number;
tags: string[][];
pubkey: string;
content: string;
created_at: number;
}
/** https://stackoverflow.com/a/8831937 */
function hashCode(str: string): number {
let hash = 0;
for (let i = 0, len = str.length; i < len; i++) {
const chr = str.charCodeAt(i);
hash = (hash << 5) - hash + chr;
hash |= 0; // Convert to 32bit integer
}
return hash;
}
async function handleMessage(msg: InputMessage): Promise<OutputMessage> {
const { kind, content } = msg.event;
if (kind === 1 && content.length >= ANTI_DUPLICATION_MIN_LENGTH) {
const db = new Keydb('sqlite:///tmp/strfry-anti-duplication-policy.sqlite3');
const hash = String(hashCode(content));
if (await db.get(hash)) {
await db.set(hash, 1, ANTI_DUPLICATION_TTL);
return {
id: msg.event.id,
action: 'shadowReject',
msg: '',
};
}
await db.set(hash, 1, ANTI_DUPLICATION_TTL);
}
return {
id: msg.event.id,
action: 'accept',
msg: '',
};
}
for await (const line of readLines(Deno.stdin)) {
console.log(JSON.stringify(await handleMessage(JSON.parse(line))));
}

1
deno.json
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{
"lock": false,
"tasks": {
},
"lint": {

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deno.lock Normal file
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entrypoint.example.ts Normal file
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#!/bin/sh
//bin/true; exec deno run -A "$0" "$@"
import {
antiDuplicationPolicy,
hellthreadPolicy,
noopPolicy,
pipeline,
rateLimitPolicy,
readStdin,
writeStdout,
} from './mod.ts';
const msg = await readStdin();
const result = await pipeline(msg, [
noopPolicy,
[hellthreadPolicy, { limit: 100 }],
[antiDuplicationPolicy, { ttl: 60000, minLength: 50 }],
[rateLimitPolicy, { whitelist: ['127.0.0.1'] }],
]);
writeStdout(result);

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hellthread-policy.ts
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#!/usr/bin/env -S deno run
import { readLines } from 'https://deno.land/std@0.178.0/io/mod.ts';
const HELLTHREAD_LIMIT = Number(Deno.env.get('HELLTHREAD_LIMIT') || 100);
interface InputMessage {
type: 'new' | 'lookback';
event: Event;
receivedAt: number;
sourceType: 'IP4' | 'IP6' | 'Import' | 'Stream' | 'Sync';
sourceInfo: string;
}
interface OutputMessage {
id: string;
action: 'accept' | 'reject' | 'shadowReject';
msg: string;
}
interface Event {
id: string;
sig: string;
kind: number;
tags: string[][];
pubkey: string;
content: string;
created_at: number;
}
function handleMessage(msg: InputMessage): OutputMessage {
if (msg.event.kind === 1) {
const p = msg.event.tags.filter((tag) => tag[0] === 'p');
if (p.length > HELLTHREAD_LIMIT) {
return {
id: msg.event.id,
action: 'reject',
msg: `Event rejected due to ${p.length} "p" tags (${HELLTHREAD_LIMIT} is the limit).`,
};
}
}
return {
id: msg.event.id,
action: 'accept',
msg: '',
};
}
for await (const line of readLines(Deno.stdin)) {
console.log(JSON.stringify(handleMessage(JSON.parse(line))));
}

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mod.ts Normal file
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export { default as antiDuplicationPolicy } from './src/policies/anti-duplication-policy.ts';
export { default as hellthreadPolicy } from './src/policies/hellthread-policy.ts';
export { default as noopPolicy } from './src/policies/noop-policy.ts';
export { default as rateLimitPolicy } from './src/policies/rate-limit-policy.ts';
export { default as readOnlyPolicy } from './src/policies/read-only-policy.ts';
export { readStdin, writeStdout } from './src/io.ts';
export { default as pipeline } from './src/pipeline.ts';
export type { Event, InputMessage, OutputMessage, Policy } from './src/types.ts';
export type { PolicyTuple } from './src/pipeline.ts';

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noop-policy.ts
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#!/usr/bin/env -S deno run
import { readLines } from 'https://deno.land/std@0.178.0/io/mod.ts';
interface InputMessage {
type: 'new' | 'lookback';
event: Event;
receivedAt: number;
sourceType: 'IP4' | 'IP6' | 'Import' | 'Stream' | 'Sync';
sourceInfo: string;
}
interface OutputMessage {
id: string;
action: 'accept' | 'reject' | 'shadowReject';
msg: string;
}
interface Event {
id: string;
sig: string;
kind: number;
tags: string[][];
pubkey: string;
content: string;
created_at: number;
}
function handleMessage(msg: InputMessage): OutputMessage {
return {
id: msg.event.id,
action: 'accept',
msg: '',
};
}
for await (const line of readLines(Deno.stdin)) {
console.log(JSON.stringify(handleMessage(JSON.parse(line))));
}

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rate-limit-policy.ts
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@ -1,59 +0,0 @@
#!/bin/sh
//bin/true; exec deno run -A "$0" "$@"
import { readLines } from 'https://deno.land/std@0.178.0/io/mod.ts';
import { Keydb } from 'https://deno.land/x/keydb@1.0.0/sqlite.ts';
const IP_WHITELIST = (Deno.env.get('IP_WHITELIST') || '').split(',');
const RATE_LIMIT_INTERVAL = Number(Deno.env.get('RATE_LIMIT_INTERVAL') || 60000);
const RATE_LIMIT_MAX = Number(Deno.env.get('RATE_LIMIT_MAX') || 10);
interface InputMessage {
type: 'new' | 'lookback';
event: Event;
receivedAt: number;
sourceType: 'IP4' | 'IP6' | 'Import' | 'Stream' | 'Sync';
sourceInfo: string;
}
interface OutputMessage {
id: string;
action: 'accept' | 'reject' | 'shadowReject';
msg: string;
}
interface Event {
id: string;
sig: string;
kind: number;
tags: string[][];
pubkey: string;
content: string;
created_at: number;
}
async function handleMessage(msg: InputMessage): Promise<OutputMessage> {
if ((msg.sourceType === 'IP4' || msg.sourceType === 'IP6') && !IP_WHITELIST.includes(msg.sourceInfo)) {
const db = new Keydb('sqlite:///tmp/strfry-rate-limit-policy.sqlite3');
const count = await db.get<number>(msg.sourceInfo) || 0;
await db.set(msg.sourceInfo, count + 1, RATE_LIMIT_INTERVAL);
if (count >= RATE_LIMIT_MAX) {
return {
id: msg.event.id,
action: 'reject',
msg: 'Rate-limited.',
};
}
}
return {
id: msg.event.id,
action: 'accept',
msg: '',
};
}
for await (const line of readLines(Deno.stdin)) {
console.log(JSON.stringify(await handleMessage(JSON.parse(line))));
}

39
read-only-policy.ts
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#!/bin/sh
//bin/true; exec deno run -A "$0" "$@"
import { readLines } from 'https://deno.land/std@0.178.0/io/mod.ts';
interface InputMessage {
type: 'new' | 'lookback';
event: Event;
receivedAt: number;
sourceType: 'IP4' | 'IP6' | 'Import' | 'Stream' | 'Sync';
sourceInfo: string;
}
interface OutputMessage {
id: string;
action: 'accept' | 'reject' | 'shadowReject';
msg: string;
}
interface Event {
id: string;
sig: string;
kind: number;
tags: string[][];
pubkey: string;
content: string;
created_at: number;
}
function handleMessage(msg: InputMessage): OutputMessage {
return {
id: msg.event.id,
action: 'reject',
msg: 'The relay is set to read-only.',
};
}
for await (const line of readLines(Deno.stdin)) {
console.log(JSON.stringify(handleMessage(JSON.parse(line))));
}

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src/deps.ts Normal file
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export { readLines } from 'https://deno.land/std@0.181.0/io/mod.ts';
export { assert } from 'https://deno.land/std@0.181.0/testing/asserts.ts';
export { Keydb } from 'https://deno.land/x/keydb@1.0.0/sqlite.ts';

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src/io.ts Normal file
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import { readLines } from './deps.ts';
import type { InputMessage, OutputMessage } from './types.ts';
/**
* Get the first line from stdin.
* Can only be read ONCE, or else it returns undefined.
*/
async function readStdin(): Promise<InputMessage> {
const { value } = await readLines(Deno.stdin).next();
return JSON.parse(value);
}
/** Writes the output message to stdout. */
function writeStdout(msg: OutputMessage): void {
console.log(JSON.stringify(msg));
}
export { readStdin, writeStdout };

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src/pipeline.ts Normal file
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import { InputMessage, OutputMessage, Policy } from './types.ts';
/** A policy function with opts to run it with. Used by the pipeline. */
type PolicyTuple<P extends Policy = Policy> = [policy: P, opts?: InferPolicyOpts<P>];
/** Infer opts from the policy. */
type InferPolicyOpts<P> = P extends Policy<infer Opts> ? Opts : never;
/** Helper type for proper type inference of PolicyTuples. */
// https://stackoverflow.com/a/75806165
// https://stackoverflow.com/a/54608401
type Policies<T extends any[]> = {
[K in keyof T]: PolicyTuple<T[K]> | Policy<T[K]>;
};
/** Processes messages through multiple policies, bailing early on rejection. */
async function pipeline<T extends unknown[]>(msg: InputMessage, policies: [...Policies<T>]): Promise<OutputMessage> {
for (const item of policies as (Policy | PolicyTuple)[]) {
const [policy, opts] = toTuple(item);
const result = await policy(msg, opts);
if (result.action !== 'accept') {
return result;
}
}
return {
id: msg.event.id,
action: 'accept',
msg: '',
};
}
/** Coerce item into a tuple if it isn't already. */
function toTuple<P extends Policy>(item: PolicyTuple<P> | P): PolicyTuple<P> {
return typeof item === 'function' ? [item] : item;
}
export default pipeline;
export type { PolicyTuple };

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src/policies/anti-duplication-policy.ts Executable file
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import { Keydb } from '../deps.ts';
import type { Policy } from '../types.ts';
interface AntiDuplication {
/** Time in ms until a message with this content may be posted again. Default: `60000` (1 minute). */
ttl?: number;
/** Note text under this limit will be skipped by the policy. Default: `50`. */
minLength?: number;
/** Database connection string. Default: `sqlite:///tmp/strfry-anti-duplication-policy.sqlite3` */
databaseUrl?: string;
}
/**
* Prevent messages with the exact same content from being submitted repeatedly.
* It stores a hashcode for each content in an SQLite database and rate-limits them.
* Only messages that meet the minimum length criteria are selected.
*/
const antiDuplicationPolicy: Policy<AntiDuplication> = async (msg, opts) => {
const ttl = opts?.ttl ?? 60000;
const minLength = opts?.minLength ?? 50;
const databaseUrl = opts?.databaseUrl || 'sqlite:///tmp/strfry-anti-duplication-policy.sqlite3';
const { kind, content } = msg.event;
if (kind === 1 && content.length >= minLength) {
const db = new Keydb(databaseUrl);
const hash = String(hashCode(content));
if (await db.get(hash)) {
await db.set(hash, 1, ttl);
return {
id: msg.event.id,
action: 'shadowReject',
msg: '',
};
}
await db.set(hash, 1, ttl);
}
return {
id: msg.event.id,
action: 'accept',
msg: '',
};
};
/**
* Get a "good enough" unique identifier for this content.
* This algorithm was chosen because it's very fast with a low chance of collisions.
* https://stackoverflow.com/a/8831937
*/
function hashCode(str: string): number {
let hash = 0;
for (let i = 0, len = str.length; i < len; i++) {
const chr = str.charCodeAt(i);
hash = (hash << 5) - hash + chr;
hash |= 0; // Convert to 32bit integer
}
return hash;
}
export default antiDuplicationPolicy;
export type { AntiDuplication };

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src/policies/hellthread-policy.ts Executable file
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import type { Policy } from '../types.ts';
interface Hellthread {
/** Total number of "p" tags a kind 1 note may have before it's rejected. Default: `100` */
limit?: number;
}
/** Reject messages that tag too many participants. */
const hellthreadPolicy: Policy<Hellthread> = (msg, opts) => {
const limit = opts?.limit ?? 100;
if (msg.event.kind === 1) {
const p = msg.event.tags.filter((tag) => tag[0] === 'p');
if (p.length > limit) {
return {
id: msg.event.id,
action: 'reject',
msg: `Event rejected due to ${p.length} "p" tags (${limit} is the limit).`,
};
}
}
return {
id: msg.event.id,
action: 'accept',
msg: '',
};
};
export default hellthreadPolicy;
export type { Hellthread };

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src/policies/noop-policy.ts Executable file
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import type { Policy } from '../types.ts';
/**
* Minimal sample policy for demonstration purposes.
* Allows all events through.
*/
const noopPolicy: Policy<void> = (msg) => ({
id: msg.event.id,
action: 'accept',
msg: '',
});
export default noopPolicy;

50
src/policies/rate-limit-policy.ts Executable file
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import { Keydb } from '../deps.ts';
import type { Policy } from '../types.ts';
interface RateLimit {
/** How often (ms) to check whether `max` has been exceeded. Default: `60000` (1 minute). */
interval?: number;
/** Max number of requests within the `interval` until the IP is rate-limited. Default: `10`. */
max?: number;
/** List of IP addresses to skip this policy. */
whitelist?: string[];
/** Database connection string. Default: `sqlite:///tmp/strfry-rate-limit-policy.sqlite3` */
databaseUrl?: string;
}
/**
* Rate-limits users by their IP address.
* IPs are stored in an SQLite database. If you are running internal services,
* it's a good idea to at least whitelist `127.0.0.1` etc.
*/
const rateLimitPolicy: Policy<RateLimit> = async (msg, opts) => {
const interval = opts?.interval ?? 60000;
const max = opts?.max ?? 10;
const whitelist = opts?.whitelist || [];
const databaseUrl = opts?.databaseUrl || 'sqlite:///tmp/strfry-rate-limit-policy.sqlite3';
if ((msg.sourceType === 'IP4' || msg.sourceType === 'IP6') && !whitelist.includes(msg.sourceInfo)) {
const db = new Keydb(databaseUrl);
const count = await db.get<number>(msg.sourceInfo) || 0;
await db.set(msg.sourceInfo, count + 1, interval);
if (count >= max) {
return {
id: msg.event.id,
action: 'reject',
msg: 'Rate-limited.',
};
}
}
return {
id: msg.event.id,
action: 'accept',
msg: '',
};
};
export default rateLimitPolicy;
export type { RateLimit };

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src/policies/read-only-policy.test.ts Normal file
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import { assert } from '../deps.ts';
import readOnlyPolicy from './read-only-policy.ts';
Deno.test('always rejects', async () => {
const result = await readOnlyPolicy({
event: {
kind: 1,
id: '',
content: '',
created_at: 0,
pubkey: '',
sig: '',
tags: [],
},
receivedAt: 0,
sourceInfo: '127.0.0.1',
sourceType: 'IP4',
type: 'new',
});
assert(result.action === 'reject');
});

10
src/policies/read-only-policy.ts Executable file
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import type { Policy } from '../types.ts';
/** This policy rejects all messages. */
const readOnlyPolicy: Policy<void> = (msg) => ({
id: msg.event.id,
action: 'reject',
msg: 'The relay is read-only.',
});
export default readOnlyPolicy;

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src/types.ts Normal file
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/**
* strfry input message from stdin.
* https://github.com/hoytech/strfry/blob/master/docs/plugins.md#input-messages
*/
interface InputMessage {
/** Either `new` or `lookback`. */
type: 'new' | 'lookback';
/** The event posted by the client, with all the required fields such as `id`, `pubkey`, etc. */
event: Event;
/** Unix timestamp of when this event was received by the relay. */
receivedAt: number;
/** Where this event came from. Typically will be `IP4` or `IP6`, but in lookback can also be `Import`, `Stream`, or `Sync`. */
sourceType: 'IP4' | 'IP6' | 'Import' | 'Stream' | 'Sync';
/** Specifics of the event's source. Either an IP address or a relay URL (for stream/sync). */
sourceInfo: string;
}
/**
* strfry output message to be printed as JSONL (minified JSON followed by a newline) to stdout.
* https://github.com/hoytech/strfry/blob/master/docs/plugins.md#output-messages
*/
interface OutputMessage {
/** The event ID taken from the `event.id` field of the input message. */
id: string;
/** Either `accept`, `reject`, or `shadowReject`. */
action: 'accept' | 'reject' | 'shadowReject';
/** The NIP-20 response message to be sent to the client. Only used for `reject`. */
msg: string;
}
/**
* Nostr event.
* https://github.com/nostr-protocol/nips/blob/master/01.md
*/
interface Event<K extends number = number> {
id: string;
sig: string;
kind: K;
tags: string[][];
pubkey: string;
content: string;
created_at: number;
}
/**
* A policy function in this library.
* It accepts an input message, opts, and returns an output message.
*/
type Policy<Opts = unknown> = (msg: InputMessage, opts?: Opts) => Promise<OutputMessage> | OutputMessage;
export type { Event, InputMessage, OutputMessage, Policy };