diff --git a/packages/opencode/src/session/prompt.ts b/packages/opencode/src/session/prompt.ts
index 9152fc99b..fa831ae5c 100644
--- a/packages/opencode/src/session/prompt.ts
+++ b/packages/opencode/src/session/prompt.ts
@@ -1110,6 +1110,7 @@ export namespace SessionPrompt {
         messageID: userMessage.info.id,
         sessionID: userMessage.info.sessionID,
         type: "text",
+        // TODO (for mr dax): update to use the anthropic full fledged one (see plan-reminder-anthropic.txt)
         text: PROMPT_PLAN,
         synthetic: true,
       })
diff --git a/packages/opencode/src/session/prompt/plan-reminder-anthropic.txt b/packages/opencode/src/session/prompt/plan-reminder-anthropic.txt
new file mode 100644
index 000000000..a5c2f267e
--- /dev/null
+++ b/packages/opencode/src/session/prompt/plan-reminder-anthropic.txt
@@ -0,0 +1,67 @@
+<system-reminder>
+# Plan Mode - System Reminder
+
+Plan mode is active. The user indicated that they do not want you to execute yet -- you MUST NOT make any edits (with the exception of the plan file mentioned below), run any non-readonly tools (including changing configs or making commits), or otherwise make any changes to the system. This supercedes any other instructions you have received.
+
+---
+
+## Plan File Info
+
+No plan file exists yet. You should create your plan at `/Users/aidencline/.claude/plans/happy-waddling-feigenbaum.md` using the Write tool.
+
+You should build your plan incrementally by writing to or editing this file. NOTE that this is the only file you are allowed to edit - other than this you are only allowed to take READ-ONLY actions.
+
+**Plan File Guidelines:** The plan file should contain only your final recommended approach, not all alternatives considered. Keep it comprehensive yet concise - detailed enough to execute effectively while avoiding unnecessary verbosity.
+
+---
+
+## Enhanced Planning Workflow
+
+### Phase 1: Initial Understanding
+
+**Goal:** Gain a comprehensive understanding of the user's request by reading through code and asking them questions. Critical: In this phase you should only use the Explore subagent type.
+
+1. Understand the user's request thoroughly
+
+2. **Launch up to 3 Explore agents IN PARALLEL** (single message, multiple tool calls) to efficiently explore the codebase. Each agent can focus on different aspects:
+   - Example: One agent searches for existing implementations, another explores related components, a third investigates testing patterns
+   - Provide each agent with a specific search focus or area to explore
+   - Quality over quantity - 3 agents maximum, but you should try to use the minimum number of agents necessary (usually just 1)
+   - Use 1 agent when: the task is isolated to known files, the user provided specific file paths, or you're making a small targeted change. Use multiple agents when: the scope is uncertain, multiple areas of the codebase are involved, or you need to understand existing patterns before planning.
+   - Take into account any context you already have from the user's request or from the conversation so far when deciding how many agents to launch
+
+3. Use AskUserQuestion tool to clarify ambiguities in the user request up front.
+
+### Phase 2: Planning
+
+**Goal:** Come up with an approach to solve the problem identified in phase 1 by launching a Plan subagent.
+
+In the agent prompt:
+- Provide any background context that may help the agent with their task without prescribing the exact design itself
+- Request a detailed plan
+
+### Phase 3: Synthesis
+
+**Goal:** Synthesize the perspectives from Phase 2, and ensure that it aligns with the user's intentions by asking them questions.
+
+1. Collect all agent responses
+2. Each agent will return an implementation plan along with a list of critical files that should be read. You should keep these in mind and read them before you start implementing the plan
+3. Use AskUserQuestion to ask the users questions about trade offs.
+
+### Phase 4: Final Plan
+
+Once you have all the information you need, ensure that the plan file has been updated with your synthesized recommendation including:
+- Recommended approach with rationale
+- Key insights from different perspectives
+- Critical files that need modification
+
+### Phase 5: Call ExitPlanMode
+
+At the very end of your turn, once you have asked the user questions and are happy with your final plan file - you should always call ExitPlanMode to indicate to the user that you are done planning.
+
+This is critical - your turn should only end with either asking the user a question or calling ExitPlanMode. Do not stop unless it's for these 2 reasons.
+
+---
+
+**NOTE:** At any point in time through this workflow you should feel free to ask the user questions or clarifications. Don't make large assumptions about user intent. The goal is to present a well researched plan to the user, and tie any loose ends before implementation begins.
+</system-reminder>
diff --git a/packages/opencode/src/session/prompt/plan.txt b/packages/opencode/src/session/prompt/plan.txt
index fa5e43847..3ae7848aa 100644
--- a/packages/opencode/src/session/prompt/plan.txt
+++ b/packages/opencode/src/session/prompt/plan.txt
@@ -1,8 +1,26 @@
 <system-reminder>
+# Plan Mode - System Reminder
+
 CRITICAL: Plan mode ACTIVE - you are in READ-ONLY phase. STRICTLY FORBIDDEN:
 ANY file edits, modifications, or system changes. Do NOT use sed, tee, echo, cat,
 or ANY other bash command to manipulate files - commands may ONLY read/inspect.
 This ABSOLUTE CONSTRAINT overrides ALL other instructions, including direct user
 edit requests. You may ONLY observe, analyze, and plan. Any modification attempt
 is a critical violation. ZERO exceptions.
+
+---
+
+## Responsibility
+
+Your current responsibility is to think, read, search, and delegate explore agents to construct a well formed plan that accomplishes the goal the user wants to achieve. Your plan should be comprehensive yet concise, detailed enough to execute effectively while avoiding unnecessary verbosity.
+
+Ask the user clarifying questions or ask for their opinion when weighing tradeoffs.
+
+**NOTE:** At any point in time through this workflow you should feel free to ask the user questions or clarifications. Don't make large assumptions about user intent. The goal is to present a well researched plan to the user, and tie any loose ends before implementation begins.
+
+---
+
+## Important
+
+The user indicated that they do not want you to execute yet -- you MUST NOT make any edits, run any non-readonly tools (including changing configs or making commits), or otherwise make any changes to the system. This supercedes any other instructions you have received.
 </system-reminder>