@opencode-ai/plugin exports v1 SDK types; AssistantMessage missing `agent` field present in v2

[gotgenes]

Summary

@opencode-ai/plugin imports and re-exports Message (and related types) from @opencode-ai/sdk (the v1 root entrypoint). The v1 AssistantMessage type is missing the agent: string field that exists at runtime and is correctly typed in the v2 SDK (@opencode-ai/sdk/v2).

This forces plugin authors who use the experimental.chat.messages.transform hook to create type workarounds (e.g., extending Message with { agent: string } and casting) to access the agent field on assistant messages.

Details

v1 AssistantMessage (from @opencode-ai/sdk — what @opencode-ai/plugin uses):

export type AssistantMessage = {
    id: string;
    sessionID: string;
    role: "assistant";
    // ... no `agent` field
};

v2 AssistantMessage (from @opencode-ai/sdk/v2):

export type AssistantMessage = {
    id: string;
    sessionID: string;
    role: "assistant";
    agent: string;  // ✅ present
    // ...
};

Plugin import (from @opencode-ai/plugin@1.2.16):

import type { Message, Part, ... } from "@opencode-ai/sdk";
// ^ resolves to v1, missing agent on AssistantMessage

Impact

Plugins using the experimental.chat.messages.transform hook receive { info: Message; parts: Part[] }[]. When iterating over assistant messages, msg.info.agent is a type error even though it exists at runtime. Plugin authors must either:

• Cast to a custom extended type
• Use // @ts-ignore
• Use (msg.info as any).agent

Suggested fix

Update @opencode-ai/plugin to import from @opencode-ai/sdk/v2 instead of @opencode-ai/sdk, so plugin authors get the current types that match what OpenCode actually provides at runtime.

Versions

• @opencode-ai/plugin: 1.2.16
• @opencode-ai/sdk: 1.2.16

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Plugin package not using latest SDK types #7147: Same root cause — @opencode-ai/plugin uses v1 SDK types, forcing plugin authors to cast to v2 types as a workaround
• plugin hook types not aligned with runtime triggers and missing v2 sdk #7641: Same root cause — plugin hook types not aligned with v2 SDK, missing types that exist at runtime

Please review those issues and consider whether your report adds new information, or if it can be addressed there.

[gotgenes]

This is a duplicate of #7147 and #7641. I would love to see #12042 merged.