import type { ExtensionAPI } from "@bastani/atomic";
import { Type } from "typebox";

export default function (pi: ExtensionAPI) {
  // React to events
  pi.on("session_start", async (_event, ctx) => {
    ctx.ui.notify("Extension loaded!", "info");
  });

  pi.on("tool_call", async (event, ctx) => {
    if (event.toolName === "bash" && event.input.command?.includes("rm -rf")) {
      const ok = await ctx.ui.confirm("Dangerous!", "Allow rm -rf?");
      if (!ok) return { block: true, reason: "Blocked by user" };
    }
  });

  // Register a custom tool
  pi.registerTool({
    name: "greet",
    label: "Greet",
    description: "Greet someone by name",
    parameters: Type.Object({
      name: Type.String({ description: "Name to greet" }),
    }),
    async execute(toolCallId, params, signal, onUpdate, ctx) {
      return {
        content: [{ type: "text", text: `Hello, ${params.name}!` }],
        details: {},
      };
    },
  });

  // Register a command
  pi.registerCommand("hello", {
    description: "Say hello",
    handler: async (args, ctx) => {
      ctx.ui.notify(`Hello ${args || "world"}!`, "info");
    },
  });
}

atomic -e ./my-extension.ts

{
  "packages": [
    "npm:@foo/bar@1.0.0",
    "git:github.com/user/repo@v1"
  ],
  "extensions": [
    "/path/to/local/extension.ts",
    "/path/to/local/extension/dir"
  ]
}

bun install

import type { ExtensionAPI } from "@bastani/atomic";

export default function (pi: ExtensionAPI) {
  // Subscribe to events
  pi.on("event_name", async (event, ctx) => {
    // ctx.ui for user interaction
    const ok = await ctx.ui.confirm("Title", "Are you sure?");
    ctx.ui.notify("Done!", "info");
    ctx.ui.setStatus("my-ext", "Processing...");  // Footer status
    ctx.ui.setWidget("my-ext", ["Line 1", "Line 2"]);  // Widget above editor (default)
  });

  // Register tools, commands, shortcuts, flags
  pi.registerTool({ ... });
  pi.registerCommand("name", { ... });
  pi.registerShortcut("ctrl+x", { ... });
  pi.registerFlag("my-flag", { ... });
}

import type { ExtensionAPI } from "@bastani/atomic";

export default async function (pi: ExtensionAPI) {
  const response = await fetch("http://localhost:1234/v1/models");
  const payload = (await response.json()) as {
    data: Array<{
      id: string;
      name?: string;
      context_window?: number;
      max_tokens?: number;
    }>;
  };

  pi.registerProvider("local-openai", {
    baseUrl: "http://localhost:1234/v1",
    apiKey: "$LOCAL_OPENAI_API_KEY",
    api: "openai-completions",
    models: payload.data.map((model) => ({
      id: model.id,
      name: model.name ?? model.id,
      reasoning: false,
      input: ["text"],
      cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
      contextWindow: model.context_window ?? 128000,
      maxTokens: model.max_tokens ?? 4096,
    })),
  });
}

~/.atomic/agent/extensions/
└── my-extension.ts

~/.atomic/agent/extensions/
└── my-extension/
    ├── index.ts        # Entry point (exports default function)
    ├── tools.ts        # Helper module
    └── utils.ts        # Helper module

~/.atomic/agent/extensions/
└── my-extension/
    ├── package.json    # Declares dependencies and entry points
    ├── bun.lock
    ├── node_modules/   # After dependency install
    └── src/
        └── index.ts

// package.json
{
  "name": "my-extension",
  "dependencies": {
    "zod": "^3.0.0",
    "chalk": "^5.0.0"
  },
  "atomic": {
    "extensions": ["./src/index.ts"]
  }
}

Atomic starts
  │
  ├─► project_trust (user/global and CLI extensions only, before project resources load)
  ├─► session_start { reason: "startup" }
  └─► resources_discover { reason: "startup" }
      │
      ▼
user sends prompt ─────────────────────────────────────────┐
  │                                                        │
  ├─► (extension commands checked first, bypass if found)  │
  ├─► input (can intercept, transform, or handle)          │
  ├─► (skill/template expansion if not handled)            │
  ├─► before_agent_start (can inject message, modify system prompt)
  ├─► agent_start                                          │
  ├─► message_start / message_update / message_end         │
  │                                                        │
  │   ┌─── turn (repeats while LLM calls tools) ───┐       │
  │   │                                            │       │
  │   ├─► turn_start                               │       │
  │   ├─► context (can modify messages)            │       │
  │   ├─► before_provider_request (can inspect or replace payload)
  │   ├─► after_provider_response (status + headers, before stream consume)
  │   │                                            │       │
  │   │   LLM responds, may call tools:            │       │
  │   │     ├─► tool_execution_start               │       │
  │   │     ├─► tool_call (can block)              │       │
  │   │     ├─► tool_execution_update              │       │
  │   │     ├─► tool_result (can modify)           │       │
  │   │     └─► tool_execution_end                 │       │
  │   │                                            │       │
  │   ├─► turn_end                                 │       │
  │   └─► post-tool threshold preflight            │       │
  │       (may compact before the next provider request)   │
  └─► agent_end                                            │
                                                           │
user sends another prompt ◄────────────────────────────────┘

/new (new session) or /resume (switch session)
  ├─► session_before_switch (can cancel)
  ├─► session_shutdown
  ├─► session_start { reason: "new" | "resume", previousSessionFile? }
  └─► resources_discover { reason: "startup" }

/fork or /clone
  ├─► session_before_fork (can cancel)
  ├─► session_shutdown
  ├─► session_start { reason: "fork", previousSessionFile }
  └─► resources_discover { reason: "startup" }

/compact or auto-compaction
  ├─► compaction_start / compaction_end (verbatim line-compaction status)
  ├─► session_before_compact (can cancel or provide compactedText)
  └─► session_compact (after the compaction boundary is persisted)

/tree navigation
  ├─► session_before_tree (can cancel or customize)
  └─► session_tree

/model or CTRL+P (model selection/cycling)
  ├─► thinking_level_select (if model change changes/clamps thinking level)
  └─► model_select

thinking level changes (settings, keybinding, pi.setThinkingLevel())
  └─► thinking_level_select

exit (CTRL+C, CTRL+D, SIGHUP, SIGTERM)
  └─► session_shutdown

pi.on("project_trust", async (event, ctx) => {
  // event.cwd - current working directory
  // ctx has a limited trust context: cwd, mode, hasUI, and select/confirm/input/notify UI helpers
  if (ctx.hasUI && await ctx.ui.confirm("Trust project?", event.cwd)) {
    return { trusted: "yes", remember: true };
  }
  return { trusted: "undecided" };
});

pi.on("resources_discover", async (event, _ctx) => {
  // event.cwd - current working directory
  // event.reason - "startup" | "reload"
  return {
    skillPaths: ["/path/to/skills"],
    promptPaths: ["/path/to/prompts"],
    themePaths: ["/path/to/themes"],
  };
});

pi.on("session_start", async (event, ctx) => {
  // event.reason - "startup" | "reload" | "new" | "resume" | "fork"
  // event.previousSessionFile - present for "new", "resume", and "fork"
  ctx.ui.notify(`Session: ${ctx.sessionManager.getSessionFile() ?? "ephemeral"}`, "info");
});

pi.on("session_info_changed", async (event, ctx) => {
  // event.name - current normalized name, or undefined if cleared
  ctx.ui.notify(`Session renamed: ${event.name ?? "(none)"}`, "info");
});

pi.on("session_before_switch", async (event, ctx) => {
  // event.reason - "new" or "resume"
  // event.targetSessionFile - session we're switching to (only for "resume")

  if (event.reason === "new") {
    const ok = await ctx.ui.confirm("Clear?", "Delete all messages?");
    if (!ok) return { cancel: true };
  }
});

pi.on("session_before_fork", async (event, ctx) => {
  // event.entryId - ID of the selected entry
  // event.position - "before" for /fork, "at" for /clone
  return { cancel: true }; // Cancel fork/clone
  // OR
  return { skipConversationRestore: true }; // Reserved for future conversation restore control
});

pi.on("session_before_compact", async (event) => {
  const { preparation, branchEntries, parameters, reason, signal } = event;

  // preparation.region.lines - unnumbered compactable transcript lines
  // preparation.firstKeptEntryId - fixed start of the exact tail, or null when the tail is empty
  // preparation.tokensBefore - whole-context token estimate
  // parameters - compression_ratio, preserve_recent, query
  // branchEntries - raw entries on the active branch
  // reason - "manual" | "threshold" | "overflow"
  // preparation is a deep-frozen clone

  if (signal.aborted) return { cancel: true };

  // Cancel compaction:
  return { cancel: true };

  // Or replace only the prepared region. Whitespace-only text is rejected.
  return {
    compactedText: preparation.region.lines.slice(0, 40).join("\n"),
  };
});

pi.on("session_compact", async (event) => {
  // event.result - VerbatimCompactionResult (text, boundary, stats, parameters, rung)
  // event.compactionEntry - saved CompactionEntry with strategy "verbatim-lines"
  // event.fromExtension - true when session_before_compact provided compactedText
  // Observe-only: errors are isolated after persistence.
});

pi.on("session_before_tree", async (event, ctx) => {
  const { preparation, signal } = event;
  return { cancel: true };
  // OR provide custom summary:
  return { summary: { summary: "...", details: {} } };
});

pi.on("session_tree", async (event, ctx) => {
  // event.newLeafId, oldLeafId, summaryEntry, fromExtension
});

pi.on("session_shutdown", async (event, ctx) => {
  // event.reason - "quit" | "reload" | "new" | "resume" | "fork"
  // event.targetSessionFile - destination session for session replacement flows
  // Cleanup, save state, etc.
});

pi.on("before_agent_start", async (event, ctx) => {
  // event.prompt - user's prompt text
  // event.images - attached images (if any)
  // event.systemPrompt - current chained system prompt for this handler
  //   (includes changes from earlier before_agent_start handlers)
  // event.systemPromptOptions - structured options used to build the system prompt
  //   .customPrompt - any custom system prompt (from --system-prompt, SYSTEM.md, or custom templates)
  //   .selectedTools - tools currently active in the prompt
  //   .toolSnippets - one-line descriptions for each tool
  //   .promptGuidelines - custom guideline bullets
  //   .appendSystemPrompt - text from --append-system-prompt flags
  //   .cwd - working directory
  //   .contextFiles - AGENTS.md files and other loaded context files
  //   .skills - loaded skills

  return {
    // Inject a persistent message (stored in session, sent to LLM)
    message: {
      customType: "my-extension",
      content: "Additional context for the LLM",
      display: true,
    },
    // Replace the system prompt for this turn (chained across extensions)
    systemPrompt: event.systemPrompt + "\n\nExtra instructions for this turn...",
  };
});

pi.on("agent_start", async (_event, ctx) => {});
pi.on("agent_end", async (event, ctx) => {
  // event.messages - messages from this low-level run
});
pi.on("agent_settled", async (_event, ctx) => {
  // ctx.isIdle() is true unless another extension started a run.
});

pi.on("turn_start", async (event, ctx) => {
  // event.turnIndex, event.timestamp
});

pi.on("turn_end", async (event, ctx) => {
  // event.turnIndex, event.message, event.toolResults
});

pi.on("message_start", async (event, ctx) => {
  // event.message
});

pi.on("message_update", async (event, ctx) => {
  // event.message
  // event.assistantMessageEvent (token-by-token stream event)
});

pi.on("message_end", async (event, ctx) => {
  if (event.message.role !== "assistant") return;

  return {
    message: {
      ...event.message,
      usage: {
        ...event.message.usage,
        cost: {
          ...event.message.usage.cost,
          total: 0.123,
        },
      },
    },
  };
});

pi.on("tool_execution_start", async (event, ctx) => {
  // event.toolCallId, event.toolName, event.args
});

pi.on("tool_execution_update", async (event, ctx) => {
  // event.toolCallId, event.toolName, event.args, event.partialResult
});

pi.on("tool_execution_end", async (event, ctx) => {
  // event.toolCallId, event.toolName, event.result, event.isError
});

pi.on("context", async (event, ctx) => {
  // event.messages - deep copy, safe to modify
  const filtered = event.messages.filter(m => !shouldPrune(m));
  return { messages: filtered };
});

pi.on("before_provider_headers", (event, ctx) => {
  event.headers["x-session-id"] = ctx.sessionManager.getSessionId();
  delete event.headers["x-remove-me"];
});

pi.on("before_provider_request", (event, ctx) => {
  console.log(JSON.stringify(event.payload, null, 2));

  // Optional: replace payload
  // return { ...event.payload, temperature: 0 };
});

pi.on("after_provider_response", (event, ctx) => {
  // event.status - HTTP status code
  // event.headers - normalized response headers
  if (event.status === 429) {
    console.log("rate limited", event.headers["retry-after"]);
  }
});

pi.on("model_select", async (event, ctx) => {
  // event.model - newly selected model
  // event.previousModel - previous model (undefined if first selection)
  // event.source - "set" | "cycle" | "restore"

  const prev = event.previousModel
    ? `${event.previousModel.provider}/${event.previousModel.id}`
    : "none";
  const next = `${event.model.provider}/${event.model.id}`;

  ctx.ui.notify(`Model changed (${event.source}): ${prev} -> ${next}`, "info");
});

pi.on("thinking_level_select", async (event, ctx) => {
  // event.level - newly selected thinking level
  // event.previousLevel - previous thinking level

  ctx.ui.setStatus("thinking", `thinking: ${event.level}`);
});

import { isToolCallEventType } from "@bastani/atomic";

pi.on("tool_call", async (event, ctx) => {
  // event.toolName - "bash", "read", "write", "edit", "find", "search", etc.
  // event.toolCallId
  // event.input - tool parameters (mutable)

  // Built-in tools: no type params needed
  if (isToolCallEventType("bash", event)) {
    // event.input is { command: string; timeout?: number }
    event.input.command = `source ~/.profile\n${event.input.command}`;

    if (event.input.command.includes("rm -rf")) {
      return { block: true, reason: "Dangerous command" };
    }
  }

  if (isToolCallEventType("read", event)) {
    // event.input is { path: string }
    console.log(`Reading: ${event.input.path}`);
  }

  if (isToolCallEventType("search", event)) {
    // event.input is typed as SearchToolInput
    event.input.paths ??= ".";
  }
});

// my-extension.ts
export type MyToolInput = Static<typeof myToolSchema>;

import { isToolCallEventType } from "@bastani/atomic";
import type { MyToolInput } from "my-extension";

pi.on("tool_call", (event) => {
  if (isToolCallEventType<"my_tool", MyToolInput>("my_tool", event)) {
    event.input.action;  // typed
  }
});

import { isBashToolResult, isSearchToolResult } from "@bastani/atomic";

pi.on("tool_result", async (event, ctx) => {
  // event.toolName, event.toolCallId, event.input
  // event.content, event.details, event.isError

  if (isBashToolResult(event)) {
    // event.details is typed as BashToolDetails
  }

  if (isSearchToolResult(event)) {
    // event.details is typed as SearchToolDetails | undefined
  }

  const response = await fetch("https://example.com/summarize", {
    method: "POST",
    body: JSON.stringify({ content: event.content }),
    signal: ctx.signal,
  });

  // Modify result:
  return { content: [...], details: {...}, isError: false };
});

import { createLocalBashOperations } from "@bastani/atomic";

pi.on("user_bash", (event, ctx) => {
  // event.command - the bash command
  // event.excludeFromContext - true if !! prefix
  // event.cwd - working directory

  // Option 1: Provide custom operations (e.g., SSH)
  return { operations: remoteBashOps };

  // Option 2: Wrap atomic's built-in local bash backend
  const local = createLocalBashOperations();
  return {
    operations: {
      exec(command, cwd, options) {
        return local.exec(`source ~/.profile\n${command}`, cwd, options);
      }
    }
  };

  // Option 3: Full replacement - return result directly
  return { result: { output: "...", exitCode: 0, cancelled: false, truncated: false } };
});

pi.on("input", async (event, ctx) => {
  // event.text - raw input (before skill/template expansion)
  // event.images - attached images, if any
  // event.source - "interactive" (typed), "rpc" (API), or "extension" (via sendUserMessage)

  // Transform: rewrite input before expansion
  if (event.text.startsWith("?quick "))
    return { action: "transform", text: `Respond briefly: ${event.text.slice(7)}` };

  // Handle: respond without LLM (extension shows its own feedback)
  if (event.text === "ping") {
    ctx.ui.notify("pong", "info");
    return { action: "handled" };
  }

  // Route by source: skip processing for extension-injected messages
  if (event.source === "extension") return { action: "continue" };

  // Intercept skill commands before expansion
  if (event.text.startsWith("/skill:")) {
    // Could transform, block, or let pass through
  }

  return { action: "continue" };  // Default: pass through to expansion
});

import { CONFIG_DIR_NAME, type ExtensionAPI } from "@bastani/atomic";
import { join } from "node:path";

export default function (pi: ExtensionAPI) {
  pi.on("session_start", (_event, ctx) => {
    const projectConfigPath = join(ctx.cwd, CONFIG_DIR_NAME, "my-extension.json");
    // ...
  });
}

ctx.sessionManager.getEntries()       // All entries
ctx.sessionManager.getBranch()        // Current branch
ctx.sessionManager.getLeafId()        // Current leaf entry ID

pi.on("tool_result", async (event, ctx) => {
  const response = await fetch("https://example.com/api", {
    method: "POST",
    body: JSON.stringify(event),
    signal: ctx.signal,
  });

  const data = await response.json();
  return { details: data };
});

pi.registerCommand("project-status", {
  description: "Show trust state",
  handler: async (_args, ctx) => {
    ctx.ui.notify(ctx.isProjectTrusted() ? "Project is trusted" : "Project is not trusted", "info");
  },
});

pi.on("tool_call", (event, ctx) => {
  if (isFatal(event.input)) {
    ctx.shutdown();
  }
});

const usage = ctx.getContextUsage();
if (usage && usage.tokens > 100_000) {
  // ...
}

ctx.compact({
  compression_ratio: 0.5, // fraction of compactable lines to keep
  preserve_recent: 2,    // protect exactly the newest two context-visible messages
  query: "keep active migration details",
  onComplete: (result) => {
    ctx.ui.notify(`Compaction kept ${result.stats.linesKept}/${result.stats.linesBefore} lines`, "info");
  },
  onError: (error) => {
    ctx.ui.notify(`Compaction failed: ${error.message}`, "error");
  },
});

pi.on("before_agent_start", (event, ctx) => {
  const prompt = ctx.getSystemPrompt();
  console.log(`System prompt length: ${prompt.length}`);
});

pi.registerCommand("my-cmd", {
  handler: async (args, ctx) => {
    await ctx.waitForIdle();
    // Agent is now idle, safe to modify session
  },
});

const parentSession = ctx.sessionManager.getSessionFile();
const kickoff = "Continue in the replacement session";

const result = await ctx.newSession({
  parentSession,
  setup: async (sm) => {
    sm.appendMessage({
      role: "user",
      content: [{ type: "text", text: "Context from previous session..." }],
      timestamp: Date.now(),
    });
  },
  withSession: async (ctx) => {
    // Use only the replacement-session ctx here.
    await ctx.sendUserMessage(kickoff);
  },
});

if (result.cancelled) {
  // An extension cancelled the new session
}

const result = await ctx.fork("entry-id-123", {
  withSession: async (ctx) => {
    // Use only the replacement-session ctx here.
    ctx.ui.notify("Now in the forked session", "info");
  },
});
if (result.cancelled) {
  // An extension cancelled the fork
}

const cloneResult = await ctx.fork("entry-id-456", { position: "at" });
if (cloneResult.cancelled) {
  // An extension cancelled the clone
}

const result = await ctx.navigateTree("entry-id-456", {
  summarize: true,
  customInstructions: "Focus on error handling changes",
  replaceInstructions: false, // true = replace default prompt entirely
  label: "review-checkpoint",
});

const result = await ctx.switchSession("/path/to/session.jsonl", {
  withSession: async (ctx) => {
    await ctx.sendUserMessage("Resume work in the replacement session");
  },
});
if (result.cancelled) {
  // An extension cancelled the switch via session_before_switch
}

import { SessionManager } from "@bastani/atomic";

pi.registerCommand("switch", {
  description: "Switch to another session",
  handler: async (args, ctx) => {
    const sessions = await SessionManager.list(ctx.cwd);
    if (sessions.length === 0) return;
    const choice = await ctx.ui.select(
      "Pick session:",
      sessions.map(s => s.file),
    );
    if (choice) {
      await ctx.switchSession(choice, {
        withSession: async (ctx) => {
          ctx.ui.notify("Switched session", "info");
        },
      });
    }
  },
});

pi.registerCommand("handoff", {
  handler: async (_args, ctx) => {
    const kickoff = "Continue from the replacement session";
    await ctx.newSession({
      withSession: async (ctx) => {
        await ctx.sendUserMessage(kickoff);
      },
    });
  },
});

pi.registerCommand("handoff", {
  handler: async (_args, ctx) => {
    const oldSessionManager = ctx.sessionManager;
    await ctx.newSession({
      withSession: async (_ctx) => {
        // stale old objects: do not do this
        oldSessionManager.getSessionFile();
        pi.sendUserMessage("wrong");
      },
    });
  },
});

pi.registerCommand("reload-runtime", {
  description: "Reload extensions, skills, prompts, and themes",
  handler: async (_args, ctx) => {
    await ctx.reload();
    return;
  },
});

import type { ExtensionAPI } from "@bastani/atomic";
import { Type } from "typebox";

export default function (pi: ExtensionAPI) {
  pi.registerCommand("reload-runtime", {
    description: "Reload extensions, skills, prompts, and themes",
    handler: async (_args, ctx) => {
      await ctx.reload();
      return;
    },
  });

  pi.registerTool({
    name: "reload_runtime",
    label: "Reload Runtime",
    description: "Reload extensions, skills, prompts, and themes",
    parameters: Type.Object({}),
    async execute() {
      pi.sendUserMessage("/reload-runtime", { deliverAs: "followUp" });
      return {
        content: [{ type: "text", text: "Queued /reload-runtime as a follow-up command." }],
      };
    },
  });
}

import { Type } from "typebox";
import { StringEnum } from "@bastani/atomic";

pi.registerTool({
  name: "my_tool",
  label: "My Tool",
  description: "What this tool does",
  promptSnippet: "Summarize or transform text according to action",
  promptGuidelines: ["Use my_tool when the user asks to summarize previously generated text."],
  parameters: Type.Object({
    action: StringEnum(["list", "add"] as const),
    text: Type.Optional(Type.String()),
  }),
  prepareArguments(args) {
    // Optional compatibility shim. Runs before schema validation.
    // Return the current schema shape, for example to fold legacy fields
    // into the modern parameter object.
    return args;
  },

  async execute(toolCallId, params, signal, onUpdate, ctx) {
    // Stream progress
    onUpdate?.({ content: [{ type: "text", text: "Working..." }] });

    return {
      content: [{ type: "text", text: "Done" }],
      details: { result: "..." },
    };
  },

  // Optional: Custom rendering
  renderCall(args, theme, context) { ... },
  renderResult(result, options, theme, context) { ... },
});

pi.sendMessage({
  customType: "my-extension",
  content: "Message text",
  display: true,
  details: { ... },
}, {
  triggerTurn: true,
  deliverAs: "steer",
});

pi.sendMessages([
  { customType: "worker-update", content: "Ready", display: true },
  { customType: "worker-terminal", content: "Completed", display: true },
], { triggerTurn: true });

// Simple text message
pi.sendUserMessage("What is 2+2?");

// With content array (text + images)
pi.sendUserMessage([
  { type: "text", text: "Describe this image:" },
  { type: "image", source: { type: "base64", mediaType: "image/png", data: "..." } },
]);

// During streaming - must specify delivery mode
pi.sendUserMessage("Focus on error handling", { deliverAs: "steer" });
pi.sendUserMessage("And then summarize", { deliverAs: "followUp" });

pi.appendEntry("my-state", { count: 42 });

// Restore on reload
pi.on("session_start", async (_event, ctx) => {
  for (const entry of ctx.sessionManager.getEntries()) {
    if (entry.type === "custom" && entry.customType === "my-state") {
      // Reconstruct from entry.data
    }
  }
});

import { Text } from "@earendil-works/pi-tui";

pi.registerEntryRenderer("status-card", (entry, { expanded }, theme) =>
  new Text(theme.fg("accent", `${expanded ? "Details" : "Status"}: ${JSON.stringify(entry.data)}`), 0, 0)
);

pi.setSessionName("Refactor auth module");

const name = pi.getSessionName();
if (name) {
  console.log(`Session: ${name}`);
}

// Set a label
pi.setLabel(entryId, "checkpoint-before-refactor");

// Clear a label
pi.setLabel(entryId, undefined);

// Read labels via sessionManager
const label = ctx.sessionManager.getLabel(entryId);

pi.registerCommand("stats", {
  description: "Show session statistics",
  handler: async (args, ctx) => {
    const count = ctx.sessionManager.getEntries().length;
    ctx.ui.notify(`${count} entries`, "info");
  }
});

import type { AutocompleteItem } from "@earendil-works/pi-tui";

pi.registerCommand("deploy", {
  description: "Deploy to an environment",
  getArgumentCompletions: (prefix: string): AutocompleteItem[] | null => {
    const envs = ["dev", "staging", "prod"];
    const items = envs.map((e) => ({ value: e, label: e }));
    const filtered = items.filter((i) => i.value.startsWith(prefix));
    return filtered.length > 0 ? filtered : null;
  },
  handler: async (args, ctx) => {
    ctx.ui.notify(`Deploying: ${args}`, "info");
  },
});

const commands = pi.getCommands();
const bySource = commands.filter((command) => command.source === "extension");
const userScoped = commands.filter((command) => command.sourceInfo.scope === "user");

{
  name: string; // Invokable command name without the leading slash. May be suffixed like "review:1"
  description?: string;
  source: "extension" | "prompt" | "skill";
  sourceInfo: {
    path: string;
    source: string;
    scope: "user" | "project" | "temporary";
    origin: "package" | "top-level";
    baseDir?: string;
  };
}

pi.registerShortcut("ctrl+shift+p", {
  description: "Toggle plan mode",
  handler: async (ctx) => {
    ctx.ui.notify("Toggled!");
  },
});

pi.registerFlag("plan", {
  description: "Start in plan mode",
  type: "boolean",
  default: false,
});

// Check value
if (pi.getFlag("plan")) {
  // Plan mode enabled
}

const result = await pi.exec("git", ["status"], { signal, timeout: 5000 });
// result.stdout, result.stderr, result.code, result.killed

const active = pi.getActiveTools(); // ["read", "bash", ...]
const all = pi.getAllTools();
// all = [{
//   name: "read",
//   description: "Read file contents...",
//   parameters: ...,
//   promptGuidelines: ["Use read to examine files instead of cat or sed."],
//   sourceInfo: { path: "<builtin:read>", source: "builtin", scope: "temporary", origin: "top-level" }
// }, ...]
const builtinTools = all.filter((t) => t.sourceInfo.source === "builtin");
const extensionTools = all.filter((t) => t.sourceInfo.source !== "builtin" && t.sourceInfo.source !== "sdk");
pi.setActiveTools([...new Set([...active, "my_custom_tool"])]); // Keep current tools and enable my_custom_tool
pi.setActiveTools(["read", "bash"]); // Switch to read-only

const model = ctx.modelRegistry.find("anthropic", "claude-sonnet-4-5");
if (model) {
  const success = await pi.setModel(model);
  if (!success) {
    ctx.ui.notify("No API key for this model", "error");
  }
}

const current = pi.getThinkingLevel();  // "off" | "minimal" | "low" | "medium" | "high" | "xhigh" | "max"
pi.setThinkingLevel("high");

pi.events.on("my:event", (data) => { ... });
pi.events.emit("my:event", { ... });

// Register a new provider with custom models
pi.registerProvider("my-proxy", {
  name: "My Proxy",
  baseUrl: "https://proxy.example.com",
  apiKey: "$PROXY_API_KEY",  // env var reference; omit $ for a literal
  api: "anthropic-messages",
  models: [
    {
      id: "claude-sonnet-4-20250514",
      name: "Claude 4 Sonnet (proxy)",
      reasoning: false,
      input: ["text", "image"],
      cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
      contextWindow: 200000,
      maxTokens: 16384
    }
  ]
});

// Override baseUrl for an existing provider (keeps all models)
pi.registerProvider("anthropic", {
  baseUrl: "https://proxy.example.com"
});

// Register provider with OAuth support for /login
pi.registerProvider("corporate-ai", {
  baseUrl: "https://ai.corp.com",
  api: "openai-responses",
  models: [...],
  oauth: {
    name: "Corporate AI (SSO)",
    async login(callbacks) {
      // Custom OAuth flow
      callbacks.onAuth({ url: "https://sso.corp.com/..." });
      const code = await callbacks.onPrompt({ message: "Enter code:" });
      return { refresh: code, access: code, expires: Date.now() + 3600000 };
    },
    async refreshToken(credentials) {
      // Refresh logic
      return credentials;
    },
    getApiKey(credentials) {
      return credentials.access;
    }
  }
});

// Register provider-owned API-key setup for /login
pi.registerProvider("local-server", {
  name: "Local Server",
  auth: {
    apiKey: {
      name: "Local server connection",
      async login({ signal, prompt }) {
        const baseUrl = await prompt({
          type: "text",
          message: "Server URL",
          placeholder: "http://localhost:8080"
        });
        if (signal.aborted) throw new Error("Login cancelled");
        return { type: "api_key", env: { LOCAL_SERVER_URL: baseUrl } };
      }
    }
  }
});

pi.registerCommand("my-setup-teardown", {
  description: "Remove the custom proxy provider",
  handler: async (_args, _ctx) => {
    pi.unregisterProvider("my-proxy");
  },
});

export default function (pi: ExtensionAPI) {
  let items: string[] = [];

  // Reconstruct state from session
  pi.on("session_start", async (_event, ctx) => {
    items = [];
    for (const entry of ctx.sessionManager.getBranch()) {
      if (entry.type === "message" && entry.message.role === "toolResult") {
        if (entry.message.toolName === "my_tool") {
          items = entry.message.details?.items ?? [];
        }
      }
    }
  });

  pi.registerTool({
    name: "my_tool",
    // ...
    async execute(toolCallId, params, signal, onUpdate, ctx) {
      items.push("new item");
      return {
        content: [{ type: "text", text: "Added" }],
        details: { items: [...items] },  // Store for reconstruction
      };
    },
  });
}

import { withFileMutationQueue } from "@bastani/atomic";
import { mkdir, readFile, writeFile } from "node:fs/promises";
import { dirname, resolve } from "node:path";

async execute(_toolCallId, params, _signal, _onUpdate, ctx) {
  const absolutePath = resolve(ctx.cwd, params.path);

  return withFileMutationQueue(absolutePath, async () => {
    await mkdir(dirname(absolutePath), { recursive: true });
    const current = await readFile(absolutePath, "utf8");
    const next = current.replace(params.oldText, params.newText);
    await writeFile(absolutePath, next, "utf8");

    return {
      content: [{ type: "text", text: `Updated ${params.path}` }],
      details: {},
    };
  });
}