Channels

Channels contain public posts hosted by a relay. Use channelManager with a ChannelRef containing channelId and relayId. A post reference adds its accepted sequence.

Create and publish

This function from workflows.ts creates a channel, publishes a post, and edits it:

export async function publishAnnouncement(client: MeshlineClient, relayId: string) {
    const channel = await client.channelManager.createChannel(relayId, 'Announcements');
    const post = await client.channelManager.publishPost(channel.ref, {
        body: { contentType: 'text/plain', text: 'First post' },
    });
    return client.channelManager.editPost(post.ref, {
        body: { contentType: 'text/plain', text: 'Updated post' },
    });
}

Channel creation accepts optional description and moderators. updateChannel changes metadata; closeChannel closes the channel. Mutation permissions depend on the verified channel state and the caller's role.

In updates, omitted fields stay unchanged. null clears fields whose update type permits it: description/moderators in channel metadata, and body/attachments in a post. Supply a complete replacement value to replace one of those fields. deletePost records deletion; reportPost submits a report with a reason.

Follow and load history

follow(channel) resolves the channel and records the local follow. A running client synchronizes followed channels through subscriptions and polling. unfollow(channel) removes the follow. Use getFollowed(relayId?) for a local snapshot reader and getChannel(channel) to resolve channel information.

loadChannelHistory(channel, { limit, cursor }) fetches and verifies retained relay history and stores the resulting changes. Omit the cursor for the latest page, then pass the returned nextCursor to load older history. Stop when nextCursor is absent. Cursors are canonical decimal strings; do not parse and reformat them or reuse them for a different channel.

getPosts({ channelId, author }) reads locally stored posts and does not fetch remote pages. Its snapshot is ordered by channel ID and sequence. Dispose the reader when finished.

Handle changes and interruption

Observe channelChanged, followChanged, and timelineChanged. Verified signed history governs descriptors, post edits, deletion, and historical permissions. Refresh stored snapshots after changes instead of assuming every notification is a newly created post.

A lost response may leave an accepted publication pending locally. The SDK retains the original signed request and reconciles verified history; known acceptance is not reposted. Inconsistent acceptance evidence remains a visible failure rather than causing a new publication. Keep pending state across restarts.

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