diff --git a/contracts/work/long_running.go b/contracts/work/long_running.go
new file mode 100644
index 0000000..369b76c
--- /dev/null
+++ b/contracts/work/long_running.go
@@ -0,0 +1,35 @@
+package work
+
+type LongRunningWorkID string
+type LongRunningState string
+
+const (
+	LongRunningProposed  LongRunningState = "PROPOSED"
+	LongRunningRunning   LongRunningState = "RUNNING"
+	LongRunningPaused    LongRunningState = "PAUSED"
+	LongRunningBlocked   LongRunningState = "BLOCKED"
+	LongRunningCompleted LongRunningState = "COMPLETED"
+	LongRunningExhausted LongRunningState = "EXHAUSTED"
+	LongRunningCancelled LongRunningState = "CANCELLED"
+)
+
+type Investigation struct {
+	ID                   LongRunningWorkID
+	Objective            string
+	HypothesisRefs       []EvidenceRef
+	AttemptRefs          []AgentRunID
+	FindingRefs          []EvidenceRef
+	Blockers             []string
+	CheckpointRefs       []AgentCheckpointID
+	NextStep             string
+	State                LongRunningState
+	Revision             int64
+	TimeBudgetMillis     int64
+	CostBudgetMicros     int64
+	MaxAttempts          int
+	RecordedAtUnixMillis int64
+}
+
+func (w Investigation) Valid() bool {
+	return w.ID != "" && w.Objective != "" && w.State != "" && w.Revision > 0 && w.TimeBudgetMillis >= 0 && w.CostBudgetMicros >= 0 && w.MaxAttempts >= 0 && w.RecordedAtUnixMillis > 0
+}
diff --git a/dev/ACTIVE_TASK.json b/dev/ACTIVE_TASK.json
index ac473f6..688a1fc 100644
--- a/dev/ACTIVE_TASK.json
+++ b/dev/ACTIVE_TASK.json
@@ -1 +1 @@
-{"task_file":"dev/tasks/GEN2-016-intelligence-strategy-resource-cost-policy-and-personal-benchmark.json","task_id":"GEN2-016","task_revision":1}
\ No newline at end of file
+{"task_file":"dev/tasks/GEN2-017-extend-work-into-durable-longrunningwork-investigation.json","task_id":"GEN2-017","task_revision":1}
diff --git a/modules/work/domain/long_running.go b/modules/work/domain/long_running.go
new file mode 100644
index 0000000..8346a23
--- /dev/null
+++ b/modules/work/domain/long_running.go
@@ -0,0 +1,18 @@
+package domain
+
+import "git.cin.su/m/Assistant/contracts/work"
+
+func PauseInvestigation(value work.Investigation) work.Investigation {
+	if value.Valid() {
+		value.State = work.LongRunningPaused
+		value.Revision++
+	}
+	return value
+}
+func ResumeInvestigation(value work.Investigation) work.Investigation {
+	if value.Valid() && value.State == work.LongRunningPaused {
+		value.State = work.LongRunningRunning
+		value.Revision++
+	}
+	return value
+}
diff --git a/modules/work/domain/long_running_test.go b/modules/work/domain/long_running_test.go
new file mode 100644
index 0000000..9d702a5
--- /dev/null
+++ b/modules/work/domain/long_running_test.go
@@ -0,0 +1,16 @@
+package domain_test
+
+import (
+	"git.cin.su/m/Assistant/contracts/work"
+	"git.cin.su/m/Assistant/modules/work/domain"
+	"testing"
+)
+
+func TestInvestigationPauseResumeIsDurableStateTransition(t *testing.T) {
+	w := work.Investigation{ID: "i", Objective: "diagnose", State: work.LongRunningRunning, Revision: 1, RecordedAtUnixMillis: 1}
+	w = domain.PauseInvestigation(w)
+	w = domain.ResumeInvestigation(w)
+	if w.State != work.LongRunningRunning || w.Revision != 3 {
+		t.Fatalf("%#v", w)
+	}
+}