WIP: Major cleanup - move Attachment to consumers, simplify agent API

- Removed Attachment from agent package (now in web-ui/coding-agent)
- Agent.prompt now takes (text, images?: ImageContent[])
- Removed transports from web-ui (duplicate of agent package)
- Updated coding-agent to use local message types
- Updated mom package for new agent API

Remaining: Fix AgentInterface.ts to compose UserMessageWithAttachments

packages/coding-agent/src/core/agent-session.ts

@@ -13,15 +13,8 @@
  * Modes use this class and add their own I/O layer on top.
  */
 
-import type {
-	Agent,
-	AgentEvent,
-	AgentMessage,
-	AgentState,
-	Attachment,
-	ThinkingLevel,
-} from "@mariozechner/pi-agent-core";
-import type { AssistantMessage, Message, Model, TextContent } from "@mariozechner/pi-ai";
+import type { Agent, AgentEvent, AgentMessage, AgentState, ThinkingLevel } from "@mariozechner/pi-agent-core";
+import type { AssistantMessage, ImageContent, Message, Model, TextContent } from "@mariozechner/pi-ai";
 import { isContextOverflow, modelsAreEqual, supportsXhigh } from "@mariozechner/pi-ai";
 import { getAuthPath } from "../config.js";
 import { type BashResult, executeBash as executeBashCommand } from "./bash-executor.js";
@@ -83,8 +76,8 @@ export interface AgentSessionConfig {
 export interface PromptOptions {
 	/** Whether to expand file-based slash commands (default: true) */
 	expandSlashCommands?: boolean;
-	/** Image/file attachments */
-	attachments?: Attachment[];
+	/** Image attachments */
+	images?: ImageContent[];
 }
 
 /** Result from cycleModel() */
@@ -492,7 +485,7 @@ export class AgentSession {
 		// Expand file-based slash commands if requested
 		const expandedText = expandCommands ? expandSlashCommand(text, [...this._fileCommands]) : text;
 
-		await this.agent.prompt(expandedText, options?.attachments);
+		await this.agent.prompt(expandedText, options?.images);
 		await this.waitForRetry();
 	}
 

packages/coding-agent/src/core/compaction.ts

@@ -8,7 +8,7 @@
 import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import type { AssistantMessage, Model, Usage } from "@mariozechner/pi-ai";
 import { complete } from "@mariozechner/pi-ai";
-import { messageTransformer } from "./messages.js";
+import { convertToLlm } from "./messages.js";
 import { type CompactionEntry, createSummaryMessage, type SessionEntry } from "./session-manager.js";
 
 /**
@@ -337,7 +337,7 @@ export async function generateSummary(
 		: SUMMARIZATION_PROMPT;
 
 	// Transform custom messages (like bashExecution) to LLM-compatible messages
-	const transformedMessages = messageTransformer(currentMessages);
+	const transformedMessages = convertToLlm(currentMessages);
 
 	const summarizationMessages = [
 		...transformedMessages,
@@ -558,7 +558,7 @@ async function generateTurnPrefixSummary(
 ): Promise<string> {
 	const maxTokens = Math.floor(0.5 * reserveTokens); // Smaller budget for turn prefix
 
-	const transformedMessages = messageTransformer(messages);
+	const transformedMessages = convertToLlm(messages);
 	const summarizationMessages = [
 		...transformedMessages,
 		{

packages/coding-agent/src/core/custom-tools/types.ts

@@ -5,7 +5,7 @@
  * They can provide custom rendering for tool calls and results in the TUI.
  */
 
-import type { AgentTool, AgentToolResult, AgentToolUpdateCallback } from "@mariozechner/pi-ai";
+import type { AgentTool, AgentToolResult, AgentToolUpdateCallback } from "@mariozechner/pi-agent-core";
 import type { Component } from "@mariozechner/pi-tui";
 import type { Static, TSchema } from "@sinclair/typebox";
 import type { Theme } from "../../modes/interactive/theme/theme.js";

packages/coding-agent/src/core/hooks/runner.ts

@@ -2,7 +2,7 @@
  * Hook runner - executes hooks and manages their lifecycle.
  */
 
-import type { Message } from "@mariozechner/pi-ai";
+import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import type { ModelRegistry } from "../model-registry.js";
 import type { SessionManager } from "../session-manager.js";
 import type { AppendEntryHandler, LoadedHook, SendMessageHandler } from "./loader.js";
@@ -315,7 +315,7 @@ export class HookRunner {
 	 *
 	 * Note: Messages are already deep-copied by the caller (pi-ai preprocessor).
 	 */
-	async emitContext(messages: Message[]): Promise<Message[]> {
+	async emitContext(messages: AgentMessage[]): Promise<AgentMessage[]> {
 		const ctx = this.createContext();
 		let currentMessages = messages;
 

packages/coding-agent/src/core/hooks/tool-wrapper.ts

@@ -2,7 +2,7 @@
  * Tool wrapper - wraps tools with hook callbacks for interception.
  */
 
-import type { AgentTool, AgentToolUpdateCallback } from "@mariozechner/pi-ai";
+import type { AgentTool, AgentToolUpdateCallback } from "@mariozechner/pi-agent-core";
 import type { HookRunner } from "./runner.js";
 import type { ToolCallEventResult, ToolResultEventResult } from "./types.js";
 

packages/coding-agent/src/core/hooks/types.ts

@@ -151,12 +151,11 @@ export type SessionEvent =
  * Event data for context event.
  * Fired before each LLM call, allowing hooks to modify context non-destructively.
  * Original session messages are NOT modified - only the messages sent to the LLM are affected.
- * Messages are already in LLM format (Message[], not AgentMessage[]).
  */
 export interface ContextEvent {
 	type: "context";
 	/** Messages about to be sent to the LLM (deep copy, safe to modify) */
-	messages: Message[];
+	messages: AgentMessage[];
 }
 
 /**

packages/coding-agent/src/core/messages.ts

@@ -6,11 +6,7 @@
  */
 
 import type { AgentMessage } from "@mariozechner/pi-agent-core";
-import type { Message } from "@mariozechner/pi-ai";
-
-// ============================================================================
-// Custom Message Types
-// ============================================================================
+import type { ImageContent, Message, TextContent } from "@mariozechner/pi-ai";
 
 /**
  * Message type for bash executions via the ! command.
@@ -26,8 +22,6 @@ export interface BashExecutionMessage {
 	timestamp: number;
 }
 
-import type { ImageContent, TextContent } from "@mariozechner/pi-ai";
-
 /**
  * Message type for hook-injected messages via sendMessage().
  * These are custom messages that hooks can inject into the conversation.
@@ -41,36 +35,28 @@ export interface HookMessage<T = unknown> {
 	timestamp: number;
 }
 
-// Extend CustomMessages via declaration merging
+// Extend CustomAgentMessages via declaration merging
 declare module "@mariozechner/pi-agent-core" {
-	interface CustomMessages {
+	interface CustomAgentMessages {
 		bashExecution: BashExecutionMessage;
 		hookMessage: HookMessage;
 	}
 }
 
-// ============================================================================
-// Type Guards
-// ============================================================================
-
 /**
  * Type guard for BashExecutionMessage.
  */
 export function isBashExecutionMessage(msg: AgentMessage | Message): msg is BashExecutionMessage {
-	return (msg as BashExecutionMessage).role === "bashExecution";
+	return msg.role === "bashExecution";
 }
 
 /**
- * Type guard for HookAgentMessage.
+ * Type guard for HookMessage.
  */
 export function isHookMessage(msg: AgentMessage | Message): msg is HookMessage {
-	return (msg as HookMessage).role === "hookMessage";
+	return msg.role === "hookMessage";
 }
 
-// ============================================================================
-// Message Formatting
-// ============================================================================
-
 /**
  * Convert a BashExecutionMessage to user message text for LLM context.
  */
@@ -92,18 +78,15 @@ export function bashExecutionToText(msg: BashExecutionMessage): string {
 	return text;
 }
 
-// ============================================================================
-// Message Transformer
-// ============================================================================
-
 /**
  * Transform AgentMessages (including custom types) to LLM-compatible Messages.
  *
  * This is used by:
- * - Agent's messageTransformer option (for prompt calls)
+ * - Agent's transormToLlm option (for prompt calls and queued messages)
  * - Compaction's generateSummary (for summarization)
+ * - Custom hooks and tools
  */
-export function messageTransformer(messages: AgentMessage[]): Message[] {
+export function convertToLlm(messages: AgentMessage[]): Message[] {
 	return messages
 		.map((m): Message | null => {
 			if (isBashExecutionMessage(m)) {
@@ -131,5 +114,5 @@ export function messageTransformer(messages: AgentMessage[]): Message[] {
 			// Filter out unknown message types
 			return null;
 		})
-		.filter((m): m is Message => m !== null);
+		.filter((m) => m !== null);
 }

packages/coding-agent/src/core/sdk.ts

@@ -29,7 +29,7 @@
  * ```
  */
 
-import { Agent, ProviderTransport, type ThinkingLevel } from "@mariozechner/pi-agent-core";
+import { Agent, type ThinkingLevel } from "@mariozechner/pi-agent-core";
 import type { Model } from "@mariozechner/pi-ai";
 import { join } from "path";
 import { getAgentDir } from "../config.js";
@@ -39,7 +39,7 @@ import { discoverAndLoadCustomTools, type LoadedCustomTool } from "./custom-tool
 import type { CustomAgentTool } from "./custom-tools/types.js";
 import { discoverAndLoadHooks, HookRunner, type LoadedHook, wrapToolsWithHooks } from "./hooks/index.js";
 import type { HookFactory } from "./hooks/types.js";
-import { messageTransformer } from "./messages.js";
+import { convertToLlm } from "./messages.js";
 import { ModelRegistry } from "./model-registry.js";
 import { SessionManager } from "./session-manager.js";
 import { type Settings, SettingsManager, type SkillsSettings } from "./settings-manager.js";
@@ -588,26 +588,24 @@ export async function createAgentSession(options: CreateAgentSessionOptions = {}
 			thinkingLevel,
 			tools: allToolsArray,
 		},
-		messageTransformer,
-		preprocessor: hookRunner
+		convertToLlm,
+		transformContext: hookRunner
 			? async (messages) => {
 					return hookRunner.emitContext(messages);
 				}
 			: undefined,
 		queueMode: settingsManager.getQueueMode(),
-		transport: new ProviderTransport({
-			getApiKey: async () => {
-				const currentModel = agent.state.model;
-				if (!currentModel) {
-					throw new Error("No model selected");
-				}
-				const key = await modelRegistry.getApiKey(currentModel);
-				if (!key) {
-					throw new Error(`No API key found for provider "${currentModel.provider}"`);
-				}
-				return key;
-			},
-		}),
+		getApiKey: async () => {
+			const currentModel = agent.state.model;
+			if (!currentModel) {
+				throw new Error("No model selected");
+			}
+			const key = await modelRegistry.getApiKey(currentModel);
+			if (!key) {
+				throw new Error(`No API key found for provider "${currentModel.provider}"`);
+			}
+			return key;
+		},
 	});
 	time("createAgent");
 

packages/coding-agent/src/core/tools/bash.ts

@@ -2,7 +2,7 @@ import { randomBytes } from "node:crypto";
 import { createWriteStream } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
-import type { AgentTool } from "@mariozechner/pi-ai";
+import type { AgentTool } from "@mariozechner/pi-agent-core";
 import { Type } from "@sinclair/typebox";
 import { spawn } from "child_process";
 import { getShellConfig, killProcessTree } from "../../utils/shell.js";

packages/coding-agent/src/core/tools/edit.ts

@@ -1,4 +1,4 @@
-import type { AgentTool } from "@mariozechner/pi-ai";
+import type { AgentTool } from "@mariozechner/pi-agent-core";
 import { Type } from "@sinclair/typebox";
 import * as Diff from "diff";
 import { constants } from "fs";

packages/coding-agent/src/core/tools/find.ts

@@ -1,4 +1,4 @@
-import type { AgentTool } from "@mariozechner/pi-ai";
+import type { AgentTool } from "@mariozechner/pi-agent-core";
 import { Type } from "@sinclair/typebox";
 import { spawnSync } from "child_process";
 import { existsSync } from "fs";

packages/coding-agent/src/core/tools/grep.ts

@@ -1,5 +1,5 @@
 import { createInterface } from "node:readline";
-import type { AgentTool } from "@mariozechner/pi-ai";
+import type { AgentTool } from "@mariozechner/pi-agent-core";
 import { Type } from "@sinclair/typebox";
 import { spawn } from "child_process";
 import { readFileSync, type Stats, statSync } from "fs";

packages/coding-agent/src/core/tools/index.ts

@@ -1,5 +1,3 @@
-import type { AgentTool } from "@mariozechner/pi-ai";
-
 export { type BashToolDetails, bashTool, createBashTool } from "./bash.js";
 export { createEditTool, editTool } from "./edit.js";
 export { createFindTool, type FindToolDetails, findTool } from "./find.js";
@@ -9,6 +7,7 @@ export { createReadTool, type ReadToolDetails, readTool } from "./read.js";
 export type { TruncationResult } from "./truncate.js";
 export { createWriteTool, writeTool } from "./write.js";
 
+import type { AgentTool } from "@mariozechner/pi-agent-core";
 import { bashTool, createBashTool } from "./bash.js";
 import { createEditTool, editTool } from "./edit.js";
 import { createFindTool, findTool } from "./find.js";

packages/coding-agent/src/core/tools/ls.ts

@@ -1,4 +1,4 @@
-import type { AgentTool } from "@mariozechner/pi-ai";
+import type { AgentTool } from "@mariozechner/pi-agent-core";
 import { Type } from "@sinclair/typebox";
 import { existsSync, readdirSync, statSync } from "fs";
 import nodePath from "path";

packages/coding-agent/src/core/tools/read.ts

@@ -1,4 +1,5 @@
-import type { AgentTool, ImageContent, TextContent } from "@mariozechner/pi-ai";
+import type { AgentTool } from "@mariozechner/pi-agent-core";
+import type { ImageContent, TextContent } from "@mariozechner/pi-ai";
 import { Type } from "@sinclair/typebox";
 import { constants } from "fs";
 import { access, readFile } from "fs/promises";

packages/coding-agent/src/core/tools/write.ts

@@ -1,4 +1,4 @@
-import type { AgentTool } from "@mariozechner/pi-ai";
+import type { AgentTool } from "@mariozechner/pi-agent-core";
 import { Type } from "@sinclair/typebox";
 import { mkdir, writeFile } from "fs/promises";
 import { dirname } from "path";