Tag Operations

Tag operations only work on arrays of tags.

They plug into modifyPublicTags(...), modifyHiddenTags(...), and the factory helpers built on top of them.

What It Is

The current type is simple:

type TagOperation = (tags: string[][]) => string[][] | Promise<string[][]>;

Use a tag operation when you want to add, remove, or replace tags without touching the rest of the event draft.

How To Use It

Modify public tags

import { EventFactory } from "applesauce-core";
import { addProfilePointerTag, setSingletonTag } from "applesauce-core/operations/tag/common";

const signed = await EventFactory.fromKind(3)
  .modifyPublicTags(setSingletonTag(["title", "Friends"]), addProfilePointerTag(friend))
  .sign(signer);

Modify hidden tags

import { addProfilePointerTag } from "applesauce-core/operations/tag/common";

const signed = await EventFactory.fromKind(30000)
  .as(signer)
  .modifyHiddenTags(addProfilePointerTag(secretFriend))
  .sign();

Compose tag operations

import { tagPipe } from "applesauce-core/helpers/pipeline";
import { addProfilePointerTag, setSingletonTag } from "applesauce-core/operations/tag/common";

const setupList = tagPipe(setSingletonTag(["title", "Friends"]), addProfilePointerTag(friend));

Common Tag Operations

The most common helpers come from applesauce-core/operations/tag/common:

• addProfilePointerTag() and removeProfilePointerTag()
• addEventPointerTag() and removeEventPointerTag()
• addAddressPointerTag() and removeAddressPointerTag()
• addNameValueTag() and removeNameValueTag()
• setSingletonTag() and removeSingletonTag()

import { addEventPointerTag, addNameValueTag } from "applesauce-core/operations/tag/common";

const signed = await EventFactory.fromKind(1)
  .modifyPublicTags(addEventPointerTag(parent), addNameValueTag(["subject", "Reply"]))
  .sign(signer);

Integration

Tag operations are the main building blocks for list-style factories in applesauce-common/factories/list.ts.

That keeps methods like addUser, addRelay, and addEventItem short while still reusing the same core helpers.

Best Practices

• Keep each tag operation focused on a single tag rule
• Return a new array instead of mutating tags
• Use tagPipe() to share bundles of tag logic
• Call .as(signer) before modifyHiddenTags(...) when the chain needs encrypted hidden tags