welcome

1/**
2 * Claude Code start screen. Its logo can't be replaced, so the shared
3 * wordmark and greeting are drawn in the band above the prompt, until the
4 * first prompt, slash command or `!` command lands in the transcript
5 * (`prompt.submit` misses the last two).
6 *
7 * The hook sandbox has no Node and no local time zone, so the clock, host and
8 * branch come from `date`, `uname` and `git`, read once at session start.
9 *
10 * `banner.ts` and `identity.ts` are copied beside this file at build time
11 * (see `../../default.nix`).
12 */
13import { atom, read, update } from "claude-code";
14import type { EngineInterface, Register } from "claude-code";
15import type { Welcome } from "../types";
16import {
17  dateline,
18  gradients,
19  greeting,
20  mocha,
21  project,
22  shade,
23  signature,
24  wordmark,
25  wordmarkWidth,
26} from "./banner";
27
28const welcome = atom({ plugin: "welcome", key: "welcome" } as const, null);
29const isGreeted = atom({ plugin: "welcome", key: "isGreeted" } as const, false);
30
31const gutter = 3;
32const minimumTextWidth = 30;
33
34async function lookAround($: EngineInterface, cwd: string): Promise<Welcome> {
35  const [clock, host, branch, home] = await Promise.all([
36    $.process.run(["date", "+%Y %m %d %H %M"]),
37    $.process.run(["uname", "-n"]),
38    $.process.run(["git", "-C", cwd, "branch", "--show-current"]),
39    $.env.get("HOME"),
40  ]);
41  const [year = 1970, month = 1, day = 1, hour = 0, minute = 0] = clock.stdout.trim().split(" ").map(Number);
42  const branchName = branch.exitCode === 0 ? branch.stdout.trim() : "";
43  const place = project(cwd, home ?? undefined);
44
45  return {
46    hour,
47    date: dateline(new Date(year, month - 1, day, hour, minute)),
48    where: signature(branchName ? `${place} \ue0a0 ${branchName}` : place, host.stdout.trim()),
49  };
50}
51
52export const register: Register = (on) => {
53  on("session.start", async ($, e, next) => {
54    if (e.isInteractive) {
55      const found = await lookAround($, e.cwd);
56      await update($, welcome, () => found);
57    }
58
59    return next(e);
60  });
61
62  on("session.append", async ($, e, next) => {
63    const isFirstMove = e.agentId === undefined && (e.door === "prompt" || e.door === "command");
64    if (isFirstMove) await update($, isGreeted, () => true);
65
66    return next(e);
67  });
68
69  on("ui.render", { component: "AbovePrompt" }, async ($, e, next) => {
70    const [state, greeted] = await Promise.all([read($, welcome), read($, isGreeted)]);
71
72    if (state === null || greeted || e.props.hasSurvey || e.props.view.agentId !== undefined) {
73      return next(e);
74    }
75
76    const { Box, Text } = $.ui.resolve(e);
77    const isWide = e.props.bodyColumns >= wordmarkWidth + gutter + minimumTextWidth;
78    const lines = [
79      <Text bold color={gradients.claude.at(-1)} wrap="truncate-end">
80        {greeting(state.hour)}
81      </Text>,
82      <Text color={mocha.subtext0} wrap="truncate-end">
83        {state.date}
84      </Text>,
85      <Text color={mocha.overlay1} wrap="truncate-end">
86        {state.where}
87      </Text>,
88    ];
89
90    return (
91      <Box flexDirection="column">
92        {wordmark.map((art, row) => (
93          <Box flexDirection="row">
94            {isWide && (
95              <Text>
96                {shade(art, gradients.claude).map(({ text, color }) => (
97                  <Text color={color}>{text}</Text>
98                ))}
99                {" ".repeat(wordmarkWidth - [...art].length + gutter)}
100              </Text>
101            )}
102            {lines[row]}
103          </Box>
104        ))}
105      </Box>
106    );
107  });
108};
109

1/** What the band shows, read once at session start. */
2export type Welcome = {
3  hour: number;
4  date: string;
5  where: string;
6};
7
8declare module "claude-code" {
9  interface PluginState {
10    welcome: { welcome: Welcome | null; isGreeted: boolean };
11  }
12}
13