diff --git a/src/hooks/atlas/tool-progress.ts b/src/hooks/atlas/tool-progress.ts
new file mode 100644
index 000000000..c9e48b4f6
--- /dev/null
+++ b/src/hooks/atlas/tool-progress.ts
@@ -0,0 +1,56 @@
+import type { SessionState } from "./types"
+
+const TANGIBLE_PROGRESS_TOOLS = new Set([
+  "bash",
+  "edit",
+  "write",
+])
+
+const FAILURE_TITLE_PATTERN = /(?:\berror\b|\bfailed\b|\bfailure\b|\bdenied\b|\brejected\b)/i
+const FAILURE_OUTPUT_PATTERN = /^\s*(?:error|failed|failure|denied|rejected)\b/i
+
+export const MAX_BOULDER_CONTINUATION_NO_TOOL_PROGRESS = 3
+
+export type ToolProgressOutput = {
+  title?: string
+  output?: string
+}
+
+export function isTangibleProgressTool(toolName: string): boolean {
+  return TANGIBLE_PROGRESS_TOOLS.has(toolName.toLowerCase())
+}
+
+export function didToolMakeProgress(output: ToolProgressOutput): boolean {
+  const title = output.title ?? ""
+  const body = output.output ?? ""
+  return !FAILURE_TITLE_PATTERN.test(title) && !FAILURE_OUTPUT_PATTERN.test(body)
+}
+
+export function recordToolProgress(state: SessionState, now = Date.now()): void {
+  state.awaitingToolProgressAfterContinuation = false
+  state.iterationsSinceLastToolProgress = 0
+  state.lastToolProgressAt = now
+  state.stalledContinuationReason = undefined
+}
+
+export function markContinuationInjectedAwaitingToolProgress(state: SessionState): void {
+  state.awaitingToolProgressAfterContinuation = true
+}
+
+export function updateNoToolProgressIterations(state: SessionState): number {
+  if (!state.awaitingToolProgressAfterContinuation) {
+    return state.iterationsSinceLastToolProgress ?? 0
+  }
+
+  state.awaitingToolProgressAfterContinuation = false
+  state.iterationsSinceLastToolProgress = (state.iterationsSinceLastToolProgress ?? 0) + 1
+  return state.iterationsSinceLastToolProgress
+}
+
+export function shouldAbortForNoToolProgress(state: SessionState): boolean {
+  return (state.iterationsSinceLastToolProgress ?? 0) >= MAX_BOULDER_CONTINUATION_NO_TOOL_PROGRESS
+}
+
+export function markContinuationStalled(state: SessionState, planName: string): void {
+  state.stalledContinuationReason = `Boulder continuation stalled for plan "${planName}": ${MAX_BOULDER_CONTINUATION_NO_TOOL_PROGRESS} consecutive continuation iterations produced no successful bash/edit/write tool progress.`
+}
diff --git a/src/hooks/atlas/types.ts b/src/hooks/atlas/types.ts
index 4c03d3966..c623c9fea 100644
--- a/src/hooks/atlas/types.ts
+++ b/src/hooks/atlas/types.ts
@@ -49,4 +49,8 @@ export interface SessionState {
   pendingFinalWaveTaskCount?: number
   approvedFinalWaveTaskCount?: number
   boulderCompletionNudgedAt?: Record<string, number>
+  awaitingToolProgressAfterContinuation?: boolean
+  iterationsSinceLastToolProgress?: number
+  lastToolProgressAt?: number
+  stalledContinuationReason?: string
 }