WIP feat(communities): open new members in a welcome channel and let admins set its welcome

browser-host/relay-broker-api.test.mjs

@@ -3397,6 +3397,54 @@ test("lifecycle uses dedicated shape-limited host routes, never the message writ
           ["p", transport.viewer],
         ],
       },
+      {
+        ...template,
+        kind: 9002,
+        tags: [
+          ["h", id],
+          ["landing", "false"],
+          ["welcome", ""],
+          ["welcome_title", ""],
+        ],
+      },
+      {
+        ...template,
+        kind: 9002,
+        tags: [
+          ["h", id],
+          ["landing", "true"],
+          ["welcome", "a\rb"],
+          ["welcome_title", ""],
+        ],
+      },
+      {
+        ...template,
+        kind: 9002,
+        tags: [
+          ["h", id],
+          ["landing", "true"],
+          ["welcome", ""],
+        ],
+      },
+      {
+        ...template,
+        kind: 9002,
+        tags: [
+          ["h", id],
+          ["landing", "true"],
+          ["welcome", ""],
+          ["welcome_title", "two\nlines"],
+        ],
+      },
+      {
+        ...template,
+        kind: 9002,
+        tags: [
+          ["h", id],
+          ["landing", "true"],
+          ["name", "rename"],
+        ],
+      },
       { ...template, content: "extra" },
       {
         ...template,
@@ -3463,7 +3511,23 @@ test("lifecycle uses dedicated shape-limited host routes, never the message writ
       expect(flagged).toMatchObject(flag);
       await transport.channelLifecycle.publish(flagged, signal);
     }
-    expect(h.publications).toHaveLength(4);
+    const landing = {
+      ...template,
+      kind: 9002,
+      tags: [
+        ["h", id],
+        ["landing", "true"],
+        ["welcome", "# Say hi\n\n\t**here**"],
+        ["welcome_title", "Hello"],
+      ],
+    };
+    expect((await h.post("sign", landing)).status).toBe(400);
+    expect((await h.post("channel-details-sign", landing)).status).toBe(400);
+    const designated = await transport.channelLifecycle.sign(landing, signal);
+    expect(verifyEvent(designated)).toBe(true);
+    expect(designated).toMatchObject(landing);
+    await transport.channelLifecycle.publish(designated, signal);
+    expect(h.publications).toHaveLength(5);
   } finally {
     live?.dispose();
     await h.close();
@@ -4151,6 +4215,29 @@ test.each([[], [1, 42], [1, 42, 43]])(
   },
 );
 
+test("join discovery projects welcome-channel support and designation", async () => {
+  const landing = "6f1c2a4e-0b7d-4c1e-9a52-2f0d8b3c7e11";
+  const h = await harness((call) =>
+    Response.json(
+      call.url === fixtureRelayUrl
+        ? {
+            name: "Community",
+            supported_extensions: ["buzz-landing-channel"],
+            landing_channel: landing,
+          }
+        : { policy: null },
+    ),
+  );
+  try {
+    expect(await (await h.get("info")).json()).toMatchObject({
+      landingChannels: true,
+      landingChannel: landing,
+    });
+  } finally {
+    await h.close();
+  }
+});
+
 test("Builderlab HTTP accepts full agent instructions and isolates the fixed native routes", async () => {
   let openLogin;
   const opened = new Promise((resolve) => {

browser-host/relay-broker.mjs

@@ -1,4 +1,5 @@
 import { isSidebarPreferencesBatch } from "../src/features/relay/sidebar-preferences.ts";
+import { isEarlierActivityFilter } from "../src/features/relay/earlier-activity.ts";
 import {
   isCatalogKind,
   MAX_EVENT_BYTES as CATALOG_EVENT_BYTES,
@@ -26,6 +27,7 @@ import {
 } from "../src/features/repos/git.ts";
 import { validateMemberAdministrationTemplate } from "../src/features/channel-members/administration-protocol.ts";
 import { validateLifecycleTemplate } from "../src/features/relay/channel-lifecycle-protocol.ts";
+import { landingInfo } from "../src/features/relay/landing.ts";
 import { validateDetailsTemplate } from "../src/features/relay/channel-details-protocol.ts";
 import { validateArchiveRequestTemplate } from "../src/features/relay/identity-archive-protocol.ts";
 import {
@@ -749,7 +751,7 @@ export function validChannelActivityFilters(filters) {
     )
   );
 }
-export function validFilters(filters) {
+export function validFilters(filters, viewer) {
   return (
     Array.isArray(filters) &&
     filters.length >= 1 &&
@@ -767,7 +769,8 @@ export function validFilters(filters) {
           )) ||
           (filter.kinds === undefined &&
             Array.isArray(filter.ids) &&
-            filter.ids.length > 0)) &&
+            filter.ids.length > 0) ||
+          isEarlierActivityFilter(filter, viewer)) &&
         Number.isInteger(filter.limit) &&
         filter.limit >= 1 &&
         filter.limit <= MAX_LIMIT,
@@ -1319,6 +1322,7 @@ export function relayBrokerPlugin({
               name: info.name,
               icon: info.icon,
               policy: policy ?? null,
+              ...landingInfo(info),
               ...(gifSearchPath
                 ? {
                     supported_extensions: ["buzz-gif"],
@@ -3146,7 +3150,7 @@ export function relayBrokerPlugin({
             !readPublishing &&
             !snapshot &&
             !channelActivity &&
-            !validFilters(filters)
+            !validFilters(filters, viewer)
           )
             return json(res, 400, { error: "Read filter rejected" });
           if (publishing || readPublishing) {

browser-host/relay-broker.test.mjs

@@ -16,6 +16,12 @@ test("read broker accepts non-channel finite reads without relaxing filter budge
     { kinds: [9], "#e": ["root"], depth_limit: 10, limit: 80 },
   ])
     assert.equal(validFilters([filter]), true);
+  // The welcome card's one question: has the viewer written anything yet?
+  const viewer = "a".repeat(64);
+  assert.equal(
+    validFilters([{ authors: [viewer], until: 1788810000, limit: 1 }], viewer),
+    true,
+  );
   for (const filters of [
     [],
     Array(5).fill({ kinds: [0], limit: 1 }),
@@ -25,8 +31,19 @@ test("read broker accepts non-channel finite reads without relaxing filter budge
     [{ kinds: [65536], limit: 1 }],
     [{ kinds: [], limit: 1 }],
     [{ limit: 1 }],
+    // Only that exact shape, about the broker's own identity, may omit kinds.
+    [{ authors: [viewer], limit: 1 }],
+    [{ authors: [viewer], until: 1788810000, limit: 2 }],
+    [{ authors: [viewer, "b".repeat(64)], until: 1, limit: 1 }],
+    [{ authors: [viewer], until: 1, limit: 1, "#h": ["channel"] }],
+    [{ authors: ["viewer"], until: 1, limit: 1 }],
+    [{ authors: ["b".repeat(64)], until: 1788810000, limit: 1 }],
   ])
-    assert.equal(validFilters(filters), false);
+    assert.equal(validFilters(filters, viewer), false);
+  assert.equal(
+    validFilters([{ authors: [viewer], until: 1788810000, limit: 1 }]),
+    false,
+  );
 });
 
 test("broker signing is limited to bounded channel messages and canonical direct and nested replies", () => {

docs/buzz-help.md

@@ -462,6 +462,38 @@ revokes all of them, and a pairing unused for 30 days expires.
   - **You don't have access to this community**: when you're signed in through
     the community's server, it names the account it refused and offers
     **Switch account**. **Check again** once an admin has added you.
+- **Welcome channel**: on relays that support it, a community can choose a
+  public channel that new members join and open first. There, a new member
+  sees a welcome card above the message box, showing the community's message
+  or a default one. Choose **Dismiss** to hide it on this computer; it stays
+  hidden even if the title or message changes, though a welcome moved to
+  another channel can show once more there. People who had already written in the
+  community never see it, though someone who has never posted may see it once
+  on each new device. The card isn't a message: it can't be replied to or
+  deleted. While
+  a new member's channels arrive, Messages says it is opening them, and waits a
+  few seconds for the welcome channel rather than open another conversation
+  first. If none arrive, **Try again** checks for them again; a welcome channel
+  that arrives later still opens. Owners and admins choose the channel and edit
+  the card's title and message in **Settings → Community admin → Welcome**. The
+  message editor has the composer's formatting toolbar and shortcuts. The
+  default title names the community when the relay or you have given it a
+  name, and is just "Welcome" otherwise. The message is saved as Markdown, up
+  to 4,000 characters,
+  and a published message opens as its Markdown source; identity links name
+  people without notifying them. Paste a channel's **Copy link** to link the
+  channel, or a person's **Copy npub** to link the person. People already in
+  the community keep their channels when the welcome channel changes.
+- **Starter channels**: in the same **Welcome** settings, owners and admins
+  choose which other open channels new members join, even on relays without a
+  welcome channel. Only starter channels are listed, each with **Remove**;
+  **Add a channel** searches the others. Until you type a name, this picker and
+  the welcome channel picker list the first 50 channels. Adding and removing
+  change the draft; **Save** publishes them with the welcome, and **Cancel**
+  discards them. A saved change applies to people who join
+  afterwards, not to current members; in an open community it also adds
+  returning people who were never in that channel. Archiving a starter channel
+  or making it private pauses it until it is public again.
 - **Finding channels**: search's **Channels** tab lists the community's open
   channels you can join, with their member counts; typing also matches channels
   you're in. Opening an unjoined channel shows a preview with **Join**. Private