diff --git a/src/agents/atlas/default-prompt-sections.ts b/src/agents/atlas/default-prompt-sections.ts
index 572986e9f..d24ad3fbf 100644
--- a/src/agents/atlas/default-prompt-sections.ts
+++ b/src/agents/atlas/default-prompt-sections.ts
@@ -133,7 +133,7 @@ Count remaining **top-level task** checkboxes. Ignore nested verification/eviden
 [ ] Plan: Read plan file, confirmed current progress
 \`\`\`
 
-**If verification fails**: Resume the SAME session with the ACTUAL error output:
+**If verification fails**: Resume the SAME task with the ACTUAL error output:
 \`\`\`typescript
 task(
   task_id="ses_xyz789",
@@ -150,7 +150,7 @@ Every \`task()\` output includes a task_id. STORE IT.
 
 When a task fails:
 1. Diagnose what actually broke. Read the error, read the file, do not guess.
-2. **Resume the SAME session** so the subagent keeps its full context:
+2. **Resume the SAME task via \`task_id\`** so the subagent keeps its full context:
     \`\`\`typescript
     task(
       task_id="ses_xyz789",
diff --git a/src/agents/hephaestus/gpt-5-3-codex.ts b/src/agents/hephaestus/gpt-5-3-codex.ts
index 869614bf6..0b6070011 100644
--- a/src/agents/hephaestus/gpt-5-3-codex.ts
+++ b/src/agents/hephaestus/gpt-5-3-codex.ts
@@ -408,7 +408,7 @@ After delegation, ALWAYS verify: works as expected? follows codebase pattern? MU
 
 ### Session Continuity
 
-Every \`task()\` output includes a continuation ID (\`ses_...\`). **USE IT for follow-ups.**
+Every \`task()\` output includes a task_id. **USE IT for follow-ups.**
 
 - **Task failed/incomplete** - \`task(task_id="ses_...", prompt="Fix: {error}")\`
 - **Follow-up on result** - \`task(task_id="ses_...", prompt="Also: {question}")\`
diff --git a/src/hooks/atlas/index.test.ts b/src/hooks/atlas/index.test.ts
index 1dfa0743e..f1cb782ab 100644
--- a/src/hooks/atlas/index.test.ts
+++ b/src/hooks/atlas/index.test.ts
@@ -507,7 +507,7 @@ session_id: ses_standalone_def
       cleanupMessageStorage(sessionID)
     })
 
-     test("should include session_id and checkbox instructions in reminder", async () => {
+     test("should include task_id and checkbox instructions in reminder", async () => {
        // given - boulder state, Atlas caller
        const sessionID = "session-resume-test"
        setupMessageStorage(sessionID, "atlas")
@@ -536,10 +536,11 @@ session_id: ses_standalone_def
         output
       )
 
-      // then - should include verification instructions
+      // then - should include verification instructions and task_id guidance
       expect(output.output).toContain("LYING")
-     expect(output.output).toContain("PHASE 1")
-     expect(output.output).toContain("PHASE 2")
+      expect(output.output).toContain("PHASE 1")
+      expect(output.output).toContain("PHASE 2")
+      expect(output.output).toContain("task_id")
       
       cleanupMessageStorage(sessionID)
     })
diff --git a/src/hooks/atlas/system-reminder-templates.ts b/src/hooks/atlas/system-reminder-templates.ts
index 4df66990d..6aa9cd319 100644
--- a/src/hooks/atlas/system-reminder-templates.ts
+++ b/src/hooks/atlas/system-reminder-templates.ts
@@ -104,7 +104,7 @@ Answer honestly:
 ALL three must be YES. "Probably" = NO. "I think so" = NO. Investigate until CERTAIN.
 
 - **All 3 YES** - Proceed: mark task complete, move to next.
-- **Any NO** - Reject: resume session with \`session_id\`, fix the specific issue.
+- **Any NO** - Reject: resume with \`task_id\`, fix the specific issue.
 - **Unsure** - Reject: "unsure" = "no". Investigate until you have a definitive answer.
 
 **DO NOT proceed to the next task until all 4 phases are complete and the gate passes.**`
diff --git a/src/hooks/compaction-context-injector/compaction-context-prompt.ts b/src/hooks/compaction-context-injector/compaction-context-prompt.ts
index 11bc25747..9439ca8d4 100644
--- a/src/hooks/compaction-context-injector/compaction-context-prompt.ts
+++ b/src/hooks/compaction-context-injector/compaction-context-prompt.ts
@@ -49,8 +49,8 @@ This section is CRITICAL for reviewer agents (momus, oracle) to maintain continu
 
 ## 8. Delegated Agent Sessions
 - List ALL background agent tasks spawned during this session
-- For each: agent name, category, status, description, and **session_id**
-- **RESUME, DON'T RESTART.** Each listed session retains full context. After compaction, use \`session_id\` to continue existing agent sessions instead of spawning new ones. This saves tokens, preserves learned context, and prevents duplicate work.
+- For each: agent name, category, status, description, and **task_id**
+- **RESUME, DON'T RESTART.** Each listed delegated task retains full context. After compaction, use \`task_id\` to continue existing delegated work instead of spawning new tasks. This saves tokens, preserves learned context, and prevents duplicate work.
 
 This context is critical for maintaining continuity after compaction.
 `
diff --git a/src/hooks/compaction-context-injector/index.test.ts b/src/hooks/compaction-context-injector/index.test.ts
index fc74ea00b..635d17eae 100644
--- a/src/hooks/compaction-context-injector/index.test.ts
+++ b/src/hooks/compaction-context-injector/index.test.ts
@@ -130,7 +130,7 @@ describe("createCompactionContextInjector", () => {
       //#then
       expect(prompt).toContain("Delegated Agent Sessions")
       expect(prompt).toContain("RESUME, DON'T RESTART")
-      expect(prompt).toContain("session_id")
+      expect(prompt).toContain("task_id")
     })
 
     it("injects actual task history when backgroundManager and sessionID provided", async () => {