diff --git a/get-shit-done/workflows/autonomous.md b/get-shit-done/workflows/autonomous.md
index c6363a32f..88fdeba7e 100644
--- a/get-shit-done/workflows/autonomous.md
+++ b/get-shit-done/workflows/autonomous.md
@@ -230,6 +230,9 @@ Proceed to 3b.
 
 **If SKIP_DISCUSS is `false` (or unset):** Execute the smart_discuss step for this phase.
 
+**IMPORTANT — Discuss must be single-pass in autonomous mode.**
+The discuss step in `--auto` mode MUST NOT loop. If CONTEXT.md already exists after discuss completes, do NOT re-invoke discuss for the same phase. The `has_context` check below is authoritative — once true, discuss is done for this phase regardless of perceived "gaps" in the context file.
+
 After smart_discuss completes, verify context was written:
 
 ```bash
diff --git a/get-shit-done/workflows/discuss-phase.md b/get-shit-done/workflows/discuss-phase.md
index aaf6839ed..90a9f84ae 100644
--- a/get-shit-done/workflows/discuss-phase.md
+++ b/get-shit-done/workflows/discuss-phase.md
@@ -665,6 +665,16 @@ Each answer (or answer set, in batch mode) should reveal the next question or ne
 ```
 After all areas are auto-resolved, skip the "Explore more gray areas" prompt and proceed directly to write_context.
 
+**CRITICAL — Auto-mode pass cap:**
+In `--auto` mode, the discuss step MUST complete in a **single pass**. After writing CONTEXT.md once, you are DONE — proceed immediately to write_context and then auto_advance. Do NOT re-read your own CONTEXT.md to find "gaps", "undefined types", or "missing decisions" and run additional passes. This creates a self-feeding loop where each pass generates references that the next pass treats as gaps, consuming unbounded time and resources.
+
+Check the pass cap from config:
+```bash
+MAX_PASSES=$(node "$HOME/.claude/get-shit-done/bin/gsd-tools.cjs" config-get workflow.max_discuss_passes 2>/dev/null || echo "3")
+```
+
+If you have already written and committed CONTEXT.md, the discuss step is complete. Move on.
+
 **Interactive mode (no `--auto`):**
 
 **For each area:**
diff --git a/sdk/prompts/workflows/discuss-phase.md b/sdk/prompts/workflows/discuss-phase.md
index 4db4cc5c6..8c6abe155 100644
--- a/sdk/prompts/workflows/discuss-phase.md
+++ b/sdk/prompts/workflows/discuss-phase.md
@@ -64,6 +64,19 @@ Analyze the phase to identify gray areas:
 5. **Log each decision** with rationale
 </step>
 
+<step name="pass_guard">
+**CRITICAL — Single-pass guard:**
+This step MUST complete in ONE pass. After writing CONTEXT.md, you are DONE. Do NOT re-read your own CONTEXT.md to identify "gaps", "undefined types", or "missing references" and run additional passes. Each decision naturally references other types and interfaces — this is expected, not a gap. The planner and executor will handle implementation details.
+
+Self-referential gap-finding creates an infinite loop where:
+1. Pass N creates decisions referencing types/interfaces
+2. Pass N+1 "discovers" those references as "gaps"
+3. Pass N+1 creates new decisions that reference more types
+4. Repeat forever
+
+Write your decisions once, comprehensively, then stop.
+</step>
+
 <step name="write_context">
 Create CONTEXT.md capturing decisions made:
 
diff --git a/sdk/src/config.ts b/sdk/src/config.ts
index 381e2120d..0ab7b7ff2 100644
--- a/sdk/src/config.ts
+++ b/sdk/src/config.ts
@@ -31,6 +31,8 @@ export interface WorkflowConfig {
   research_before_questions: boolean;
   discuss_mode: string;
   skip_discuss: boolean;
+  /** Maximum self-discuss passes in auto/headless mode before forcing proceed. Default: 3. */
+  max_discuss_passes: number;
 }
 
 export interface HooksConfig {
@@ -82,6 +84,7 @@ export const CONFIG_DEFAULTS: GSDConfig = {
     research_before_questions: false,
     discuss_mode: 'discuss',
     skip_discuss: false,
+    max_discuss_passes: 3,
   },
   hooks: {
     context_warnings: true,
diff --git a/sdk/src/phase-runner.ts b/sdk/src/phase-runner.ts
index 2e78139e8..c38a9a2d1 100644
--- a/sdk/src/phase-runner.ts
+++ b/sdk/src/phase-runner.ts
@@ -419,8 +419,9 @@ export class PhaseRunner {
       const contextFiles = await this.contextEngine.resolveContextFiles(PhaseType.Discuss);
       let prompt = await this.promptFactory.buildPrompt(PhaseType.Discuss, null, contextFiles);
 
-      // Supplement with self-discuss instructions
-      prompt += '\n\n## Self-Discuss Mode\n\nYou are the AI discussing decisions with yourself. No human is present. Identify 3-5 gray areas in the project scope, reason through each one, make opinionated choices, and write CONTEXT.md with your decisions.';
+      // Supplement with self-discuss instructions with pass cap
+      const maxPasses = this.config.workflow.max_discuss_passes ?? 3;
+      prompt += `\n\n## Self-Discuss Mode\n\nYou are the AI discussing decisions with yourself. No human is present. Identify 3-5 gray areas in the project scope, reason through each one, make opinionated choices, and write CONTEXT.md with your decisions.\n\n**CRITICAL: Single-pass only.** You MUST complete all decisions in ONE pass and write CONTEXT.md once. Do NOT re-read your own CONTEXT.md to find "gaps" and do additional passes. The maximum allowed passes is ${maxPasses} — if you have already written CONTEXT.md, you are DONE. Proceed to the next workflow step. Self-referential gap-finding loops waste resources without adding value.`;
 
       planResult = await runPhaseStepSession(
         prompt,