diff --git a/.env.example b/.env.example
index 45b1c75..d4334cf 100644
--- a/.env.example
+++ b/.env.example
@@ -16,6 +16,15 @@ CLAUDE_CODE_OAUTH_TOKEN=
 ANTHROPIC_API_KEY=
 CLAUDE_MODEL=
 CLAUDE_CODE_PATH=
+# Claude binary observability: off | stdout | file | both
+CLAUDE_OBSERVABILITY_MODE=off
+# CLAUDE_OBSERVABILITY_VERBOSITY: summary | full
+CLAUDE_OBSERVABILITY_VERBOSITY=summary
+# Relative to repository workspace root in UI/provider runs.
+CLAUDE_OBSERVABILITY_LOG_PATH=.ai_ops/events/claude-trace.ndjson
+CLAUDE_OBSERVABILITY_INCLUDE_PARTIAL=false
+CLAUDE_OBSERVABILITY_DEBUG=false
+CLAUDE_OBSERVABILITY_DEBUG_LOG_PATH=
 
 # Agent management limits
 AGENT_MAX_CONCURRENT=4
diff --git a/.gitignore b/.gitignore
index 736c4c3..5250936 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@ dist
 mcp.config.json
 .ai_ops
 .agent-context
+.workspace
\ No newline at end of file
diff --git a/README.md b/README.md
index 45c2198..2b3dd9a 100644
--- a/README.md
+++ b/README.md
@@ -95,6 +95,7 @@ The UI provides:
 - graph visualizer with topology/retry rendering, edge trigger labels, node economics (duration/cost/tokens), and critical-path highlighting
 - node inspector with attempt metadata and injected `ResolvedExecutionContext` sandbox payload
 - live runtime event feed from `AGENT_RUNTIME_EVENT_LOG_PATH` with severity coloring (including security mirror events)
+- Claude trace feed from `CLAUDE_OBSERVABILITY_LOG_PATH` (query lifecycle, SDK message types/subtypes, and errors)
 - run trigger + kill switch backed by `SchemaDrivenExecutionEngine.runSession(...)`
   - run mode selector: `provider` (real Codex/Claude execution) or `mock` (deterministic dry-run executor)
   - provider selector: `codex` or `claude`
@@ -108,6 +109,7 @@ Provider mode notes:
 - `provider=codex` uses existing OpenAI/Codex auth settings (`OPENAI_AUTH_MODE`, `CODEX_API_KEY`, `OPENAI_API_KEY`).
 - `provider=claude` uses Claude auth resolution (`CLAUDE_CODE_OAUTH_TOKEN` preferred, otherwise `ANTHROPIC_API_KEY`, or existing Claude Code login state).
 - `CLAUDE_MODEL` should be a Claude model id/alias recognized by Claude Code (for example `claude-sonnet-4-6`); `anthropic/...` prefixes are normalized automatically.
+- Claude provider runs can emit Claude SDK/CLI internals to stdout and/or NDJSON with `CLAUDE_OBSERVABILITY_*` settings.
 
 ## Manifest Semantics
 
@@ -202,6 +204,30 @@ Notes:
   - `security.tool.invocation_allowed`
   - `security.tool.invocation_blocked`
 
+## Claude Observability
+
+- `CLAUDE_OBSERVABILITY_MODE=stdout` prints structured Claude query internals (tool progress, system events, stderr, result lifecycle) to stdout as JSON lines prefixed with `[claude-trace]`.
+- `CLAUDE_OBSERVABILITY_MODE=file` appends the same records to `CLAUDE_OBSERVABILITY_LOG_PATH`.
+- `CLAUDE_OBSERVABILITY_MODE=both` enables both outputs.
+- Output samples high-frequency `tool_progress` events to avoid log flooding while retaining suppression counters.
+- `assistant` and `user` message records are retained so turn flow is inspectable end-to-end.
+- `CLAUDE_OBSERVABILITY_VERBOSITY=summary` stores compact metadata; `full` stores redacted full SDK message payloads.
+- `CLAUDE_OBSERVABILITY_INCLUDE_PARTIAL=true` enables and emits sampled partial assistant stream events from the SDK.
+- `CLAUDE_OBSERVABILITY_DEBUG=true` enables Claude SDK debug mode.
+- `CLAUDE_OBSERVABILITY_DEBUG_LOG_PATH` writes Claude SDK debug output to a file (also enables debug mode).
+- In UI/provider mode, `CLAUDE_OBSERVABILITY_LOG_PATH` resolves relative to the repo workspace root.
+- UI API: `GET /api/claude-trace?limit=<n>&sessionId=<id>` reads filtered Claude trace records.
+
+Example:
+
+```bash
+CLAUDE_OBSERVABILITY_MODE=both
+CLAUDE_OBSERVABILITY_VERBOSITY=summary
+CLAUDE_OBSERVABILITY_LOG_PATH=.ai_ops/events/claude-trace.ndjson
+CLAUDE_OBSERVABILITY_INCLUDE_PARTIAL=false
+CLAUDE_OBSERVABILITY_DEBUG=false
+```
+
 ### Analytics Quick Start
 
 Inspect latest events:
@@ -258,6 +284,12 @@ jq -c 'select(.severity=="critical")' .ai_ops/events/runtime-events.ndjson
 - `ANTHROPIC_API_KEY` (used when `CLAUDE_CODE_OAUTH_TOKEN` is unset)
 - `CLAUDE_MODEL`
 - `CLAUDE_CODE_PATH`
+- `CLAUDE_OBSERVABILITY_MODE` (`off`, `stdout`, `file`, or `both`)
+- `CLAUDE_OBSERVABILITY_VERBOSITY` (`summary` or `full`)
+- `CLAUDE_OBSERVABILITY_LOG_PATH`
+- `CLAUDE_OBSERVABILITY_INCLUDE_PARTIAL` (`true` or `false`)
+- `CLAUDE_OBSERVABILITY_DEBUG` (`true` or `false`)
+- `CLAUDE_OBSERVABILITY_DEBUG_LOG_PATH`
 - `MCP_CONFIG_PATH`
 
 ### Agent Manager Limits
diff --git a/src/agents/orchestration.ts b/src/agents/orchestration.ts
index 140762b..ebba1c8 100644
--- a/src/agents/orchestration.ts
+++ b/src/agents/orchestration.ts
@@ -190,6 +190,9 @@ function createActorSecurityContext(input: {
       type: `security.${event.type}`,
       severity: mapSecurityAuditSeverity(event),
       message: toSecurityAuditMessage(event),
+      ...(event.sessionId ? { sessionId: event.sessionId } : {}),
+      ...(event.nodeId ? { nodeId: event.nodeId } : {}),
+      ...(typeof event.attempt === "number" ? { attempt: event.attempt } : {}),
       metadata: toSecurityAuditMetadata(event),
     });
   };
diff --git a/src/agents/pipeline.ts b/src/agents/pipeline.ts
index ad2d71f..8e55634 100644
--- a/src/agents/pipeline.ts
+++ b/src/agents/pipeline.ts
@@ -107,6 +107,8 @@ export type ResolvedExecutionContext = {
 
 export type ActorExecutionInput = {
   sessionId: string;
+  attempt: number;
+  depth: number;
   node: PipelineNode;
   prompt: string;
   context: NodeExecutionContext;
@@ -912,6 +914,8 @@ export class PipelineExecutor {
 
           const result = await this.invokeActorExecutor({
             sessionId,
+            attempt,
+            depth: recursiveDepth,
             node,
             prompt,
             context,
@@ -1065,6 +1069,8 @@ export class PipelineExecutor {
 
   private async invokeActorExecutor(input: {
     sessionId: string;
+    attempt: number;
+    depth: number;
     node: PipelineNode;
     prompt: string;
     context: NodeExecutionContext;
@@ -1077,12 +1083,17 @@ export class PipelineExecutor {
 
       return await input.executor({
         sessionId: input.sessionId,
+        attempt: input.attempt,
+        depth: input.depth,
         node: input.node,
         prompt: input.prompt,
         context: input.context,
         signal: input.signal,
         executionContext: input.executionContext,
         mcp: this.buildActorMcpContext({
+          sessionId: input.sessionId,
+          nodeId: input.node.id,
+          attempt: input.attempt,
           executionContext: input.executionContext,
           prompt: input.prompt,
         }),
@@ -1207,6 +1218,9 @@ export class PipelineExecutor {
   }
 
   private buildActorMcpContext(input: {
+    sessionId: string;
+    nodeId: string;
+    attempt: number;
     executionContext: ResolvedExecutionContext;
     prompt: string;
   }): ActorExecutionMcpContext {
@@ -1261,7 +1275,12 @@ export class PipelineExecutor {
     };
 
     const createToolPermissionHandler = (): ActorToolPermissionHandler =>
-      this.createToolPermissionHandler(executionContext.allowedTools);
+      this.createToolPermissionHandler({
+        allowedTools: executionContext.allowedTools,
+        sessionId: input.sessionId,
+        nodeId: input.nodeId,
+        attempt: input.attempt,
+      });
 
     return {
       allowedTools: [...executionContext.allowedTools],
@@ -1273,10 +1292,20 @@ export class PipelineExecutor {
     };
   }
 
-  private createToolPermissionHandler(allowedTools: readonly string[]): ActorToolPermissionHandler {
-    const allowset = new Set(allowedTools);
+  private createToolPermissionHandler(input: {
+    allowedTools: readonly string[];
+    sessionId: string;
+    nodeId: string;
+    attempt: number;
+  }): ActorToolPermissionHandler {
+    const allowset = new Set(input.allowedTools);
     const rulesEngine = this.securityContext?.rulesEngine;
-    const toolPolicy = toAllowedToolPolicy(allowedTools);
+    const toolPolicy = toAllowedToolPolicy(input.allowedTools);
+    const toolAuditContext = {
+      sessionId: input.sessionId,
+      nodeId: input.nodeId,
+      attempt: input.attempt,
+    };
 
     return async (toolName, _input, options) => {
       const toolUseID = options.toolUseID;
@@ -1295,6 +1324,7 @@ export class PipelineExecutor {
         rulesEngine?.assertToolInvocationAllowed({
           tool: candidates[0] ?? toolName,
           toolClearance: toolPolicy,
+          context: toolAuditContext,
         });
         return {
           behavior: "deny",
@@ -1307,6 +1337,7 @@ export class PipelineExecutor {
       rulesEngine?.assertToolInvocationAllowed({
         tool: allowMatch,
         toolClearance: toolPolicy,
+        context: toolAuditContext,
       });
 
       return {
diff --git a/src/agents/session-lifecycle.ts b/src/agents/session-lifecycle.ts
index 6a60cc2..1904ef4 100644
--- a/src/agents/session-lifecycle.ts
+++ b/src/agents/session-lifecycle.ts
@@ -76,6 +76,11 @@ type GitExecutionResult = {
   stderr: string;
 };
 
+type GitWorktreeRecord = {
+  path: string;
+  branchRef?: string;
+};
+
 function toErrorMessage(error: unknown): string {
   if (error instanceof Error) {
     return error.message;
@@ -198,6 +203,40 @@ function toStringLines(value: string): string[] {
     .filter((line) => line.length > 0);
 }
 
+function parseGitWorktreeRecords(value: string): GitWorktreeRecord[] {
+  const lines = value.split("\n");
+  const records: GitWorktreeRecord[] = [];
+  let current: GitWorktreeRecord | undefined;
+
+  for (const line of lines) {
+    if (!line.trim()) {
+      if (current) {
+        records.push(current);
+        current = undefined;
+      }
+      continue;
+    }
+    if (line.startsWith("worktree ")) {
+      if (current) {
+        records.push(current);
+      }
+      current = {
+        path: line.slice("worktree ".length).trim(),
+      };
+      continue;
+    }
+    if (line.startsWith("branch ") && current) {
+      current.branchRef = line.slice("branch ".length).trim();
+    }
+  }
+
+  if (current) {
+    records.push(current);
+  }
+
+  return records;
+}
+
 export class FileSystemSessionMetadataStore {
   private readonly stateRoot: string;
 
@@ -383,11 +422,44 @@ export class SessionWorktreeManager {
     const worktreePath = maybeExisting
       ? assertAbsolutePath(maybeExisting, "existingWorktreePath")
       : this.resolveTaskWorktreePath(input.sessionId, input.taskId);
+    const branchName = this.resolveTaskBranchName(input.sessionId, input.taskId);
+    const attachedWorktree = await this.findWorktreePathForBranch(baseWorkspacePath, branchName);
+
+    if (attachedWorktree && attachedWorktree !== worktreePath) {
+      throw new Error(
+        `Task branch "${branchName}" is already attached to worktree "${attachedWorktree}", ` +
+          `expected "${worktreePath}".`,
+      );
+    }
+
+    if (!(await pathExists(worktreePath))) {
+      await runGit(["-C", baseWorkspacePath, "worktree", "prune", "--expire", "now"]);
+    }
 
     if (!(await pathExists(worktreePath))) {
       await mkdir(dirname(worktreePath), { recursive: true });
-      const branchName = this.resolveTaskBranchName(input.sessionId, input.taskId);
-      await runGit(["-C", baseWorkspacePath, "worktree", "add", "-B", branchName, worktreePath, "HEAD"]);
+      const addResult = await runGitWithResult([
+        "-C",
+        baseWorkspacePath,
+        "worktree",
+        "add",
+        "-B",
+        branchName,
+        worktreePath,
+        "HEAD",
+      ]);
+      if (addResult.exitCode !== 0) {
+        const attachedAfterFailure = await this.findWorktreePathForBranch(baseWorkspacePath, branchName);
+        if (attachedAfterFailure === worktreePath && (await pathExists(worktreePath))) {
+          return {
+            taskWorktreePath: worktreePath,
+          };
+        }
+        throw new Error(
+          `git -C ${baseWorkspacePath} worktree add -B ${branchName} ${worktreePath} HEAD failed: ` +
+            `${toGitFailureMessage(addResult)}`,
+        );
+      }
     }
 
     return {
@@ -687,4 +759,25 @@ export class SessionWorktreeManager {
     const mergeBase = result.stdout.trim();
     return mergeBase || undefined;
   }
+
+  private async findWorktreePathForBranch(
+    repoPath: string,
+    branchName: string,
+  ): Promise<string | undefined> {
+    const branchRef = `refs/heads/${branchName}`;
+    const records = await this.listWorktreeRecords(repoPath);
+    const matched = records.find((record) => record.branchRef === branchRef);
+    if (!matched) {
+      return undefined;
+    }
+    return resolve(matched.path);
+  }
+
+  private async listWorktreeRecords(repoPath: string): Promise<GitWorktreeRecord[]> {
+    const result = await runGitWithResult(["-C", repoPath, "worktree", "list", "--porcelain"]);
+    if (result.exitCode !== 0) {
+      return [];
+    }
+    return parseGitWorktreeRecords(result.stdout);
+  }
 }
diff --git a/src/config.ts b/src/config.ts
index 1c383b9..051c42f 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -16,9 +16,21 @@ export type ProviderRuntimeConfig = {
   anthropicApiKey?: string;
   claudeModel?: string;
   claudeCodePath?: string;
+  claudeObservability: ClaudeObservabilityRuntimeConfig;
 };
 
 export type OpenAiAuthMode = "auto" | "chatgpt" | "api_key";
+export type ClaudeObservabilityMode = "off" | "stdout" | "file" | "both";
+export type ClaudeObservabilityVerbosity = "summary" | "full";
+
+export type ClaudeObservabilityRuntimeConfig = {
+  mode: ClaudeObservabilityMode;
+  verbosity: ClaudeObservabilityVerbosity;
+  logPath: string;
+  includePartialMessages: boolean;
+  debug: boolean;
+  debugLogPath?: string;
+};
 
 export type McpRuntimeConfig = {
   configPath: string;
@@ -115,6 +127,15 @@ const DEFAULT_RUNTIME_EVENTS: RuntimeEventRuntimeConfig = {
   discordAlwaysNotifyTypes: ["session.started", "session.completed", "session.failed"],
 };
 
+const DEFAULT_CLAUDE_OBSERVABILITY: ClaudeObservabilityRuntimeConfig = {
+  mode: "off",
+  verbosity: "summary",
+  logPath: ".ai_ops/events/claude-trace.ndjson",
+  includePartialMessages: false,
+  debug: false,
+  debugLogPath: undefined,
+};
+
 function readOptionalString(
   env: NodeJS.ProcessEnv,
   key: string,
@@ -274,6 +295,26 @@ function parseOpenAiAuthMode(raw: string): OpenAiAuthMode {
   );
 }
 
+function parseClaudeObservabilityMode(raw: string): ClaudeObservabilityMode {
+  if (raw === "off" || raw === "stdout" || raw === "file" || raw === "both") {
+    return raw;
+  }
+
+  throw new Error(
+    'Environment variable CLAUDE_OBSERVABILITY_MODE must be one of: "off", "stdout", "file", "both".',
+  );
+}
+
+function parseClaudeObservabilityVerbosity(raw: string): ClaudeObservabilityVerbosity {
+  if (raw === "summary" || raw === "full") {
+    return raw;
+  }
+
+  throw new Error(
+    'Environment variable CLAUDE_OBSERVABILITY_VERBOSITY must be one of: "summary", "full".',
+  );
+}
+
 function deepFreeze<T>(value: T): Readonly<T> {
   if (value === null || typeof value !== "object") {
     return value;
@@ -360,6 +401,38 @@ export function loadConfig(env: NodeJS.ProcessEnv = process.env): Readonly<AppCo
       anthropicApiKey,
       claudeModel: normalizeClaudeModel(readOptionalString(env, "CLAUDE_MODEL")),
       claudeCodePath: readOptionalString(env, "CLAUDE_CODE_PATH"),
+      claudeObservability: {
+        mode: parseClaudeObservabilityMode(
+          readStringWithFallback(
+            env,
+            "CLAUDE_OBSERVABILITY_MODE",
+            DEFAULT_CLAUDE_OBSERVABILITY.mode,
+          ),
+        ),
+        verbosity: parseClaudeObservabilityVerbosity(
+          readStringWithFallback(
+            env,
+            "CLAUDE_OBSERVABILITY_VERBOSITY",
+            DEFAULT_CLAUDE_OBSERVABILITY.verbosity,
+          ),
+        ),
+        logPath: readStringWithFallback(
+          env,
+          "CLAUDE_OBSERVABILITY_LOG_PATH",
+          DEFAULT_CLAUDE_OBSERVABILITY.logPath,
+        ),
+        includePartialMessages: readBooleanWithFallback(
+          env,
+          "CLAUDE_OBSERVABILITY_INCLUDE_PARTIAL",
+          DEFAULT_CLAUDE_OBSERVABILITY.includePartialMessages,
+        ),
+        debug: readBooleanWithFallback(
+          env,
+          "CLAUDE_OBSERVABILITY_DEBUG",
+          DEFAULT_CLAUDE_OBSERVABILITY.debug,
+        ),
+        debugLogPath: readOptionalString(env, "CLAUDE_OBSERVABILITY_DEBUG_LOG_PATH"),
+      },
     },
     mcp: {
       configPath: readStringWithFallback(env, "MCP_CONFIG_PATH", "./mcp.config.json"),
diff --git a/src/security/rules-engine.ts b/src/security/rules-engine.ts
index 5b5d723..0317828 100644
--- a/src/security/rules-engine.ts
+++ b/src/security/rules-engine.ts
@@ -13,41 +13,43 @@ import {
 } from "./schemas.js";
 
 export type SecurityAuditEvent =
-  | {
+  | ({
       type: "shell.command_profiled";
-      timestamp: string;
       command: string;
       cwd: string;
       parsed: ParsedShellScript;
-    }
-  | {
+    } & SecurityAuditContext)
+  | ({
       type: "shell.command_allowed";
-      timestamp: string;
       command: string;
       cwd: string;
       commandCount: number;
-    }
-  | {
+    } & SecurityAuditContext)
+  | ({
       type: "shell.command_blocked";
-      timestamp: string;
       command: string;
       cwd: string;
       reason: string;
       code: string;
       details?: Record<string, unknown>;
-    }
-  | {
+    } & SecurityAuditContext)
+  | ({
       type: "tool.invocation_allowed";
-      timestamp: string;
       tool: string;
-    }
-  | {
+    } & SecurityAuditContext)
+  | ({
       type: "tool.invocation_blocked";
-      timestamp: string;
       tool: string;
       reason: string;
       code: string;
-    };
+    } & SecurityAuditContext);
+
+export type SecurityAuditContext = {
+  timestamp: string;
+  sessionId?: string;
+  nodeId?: string;
+  attempt?: number;
+};
 
 export type SecurityAuditSink = (event: SecurityAuditEvent) => void;
 
@@ -102,6 +104,28 @@ function toNow(): string {
   return new Date().toISOString();
 }
 
+function toAuditContext(input?: {
+  sessionId?: string;
+  nodeId?: string;
+  attempt?: number;
+}): SecurityAuditContext {
+  const output: SecurityAuditContext = {
+    timestamp: toNow(),
+  };
+
+  if (input?.sessionId) {
+    output.sessionId = input.sessionId;
+  }
+  if (input?.nodeId) {
+    output.nodeId = input.nodeId;
+  }
+  if (typeof input?.attempt === "number" && Number.isInteger(input.attempt) && input.attempt >= 1) {
+    output.attempt = input.attempt;
+  }
+
+  return output;
+}
+
 export class SecurityRulesEngine {
   private readonly policy: ShellValidationPolicy;
   private readonly allowedBinaries: Set<string>;
@@ -136,6 +160,11 @@ export class SecurityRulesEngine {
     command: string;
     cwd: string;
     toolClearance?: ToolClearancePolicy;
+    context?: {
+      sessionId?: string;
+      nodeId?: string;
+      attempt?: number;
+    };
   }): Promise<ValidatedShellCommand> {
     const resolvedCwd = resolve(input.cwd);
 
@@ -147,22 +176,22 @@ export class SecurityRulesEngine {
         : undefined;
 
       this.emit({
+        ...toAuditContext(input.context),
         type: "shell.command_profiled",
-        timestamp: toNow(),
         command: input.command,
         cwd: resolvedCwd,
         parsed,
       });
 
       for (const command of parsed.commands) {
-        this.assertBinaryAllowed(command, toolClearance);
+        this.assertBinaryAllowed(command, toolClearance, input.context);
         this.assertAssignmentsAllowed(command);
         this.assertArgumentPaths(command, resolvedCwd);
       }
 
       this.emit({
+        ...toAuditContext(input.context),
         type: "shell.command_allowed",
-        timestamp: toNow(),
         command: input.command,
         cwd: resolvedCwd,
         commandCount: parsed.commandCount,
@@ -175,8 +204,8 @@ export class SecurityRulesEngine {
     } catch (error) {
       if (error instanceof SecurityViolationError) {
         this.emit({
+          ...toAuditContext(input.context),
           type: "shell.command_blocked",
-          timestamp: toNow(),
           command: input.command,
           cwd: resolvedCwd,
           reason: error.message,
@@ -196,13 +225,18 @@ export class SecurityRulesEngine {
   assertToolInvocationAllowed(input: {
     tool: string;
     toolClearance: ToolClearancePolicy;
+    context?: {
+      sessionId?: string;
+      nodeId?: string;
+      attempt?: number;
+    };
   }): void {
     const policy = parseToolClearancePolicy(input.toolClearance);
 
     if (policy.banlist.includes(input.tool)) {
       this.emit({
+        ...toAuditContext(input.context),
         type: "tool.invocation_blocked",
-        timestamp: toNow(),
         tool: input.tool,
         reason: `Tool "${input.tool}" is explicitly banned by policy.`,
         code: "TOOL_BANNED",
@@ -220,8 +254,8 @@ export class SecurityRulesEngine {
 
     if (policy.allowlist.length > 0 && !policy.allowlist.includes(input.tool)) {
       this.emit({
+        ...toAuditContext(input.context),
         type: "tool.invocation_blocked",
-        timestamp: toNow(),
         tool: input.tool,
         reason: `Tool "${input.tool}" is not present in allowlist.`,
         code: "TOOL_NOT_ALLOWED",
@@ -238,8 +272,8 @@ export class SecurityRulesEngine {
     }
 
     this.emit({
+      ...toAuditContext(input.context),
       type: "tool.invocation_allowed",
-      timestamp: toNow(),
       tool: input.tool,
     });
   }
@@ -290,6 +324,11 @@ export class SecurityRulesEngine {
   private assertBinaryAllowed(
     command: ParsedShellCommand,
     toolClearance?: ToolClearancePolicy,
+    context?: {
+      sessionId?: string;
+      nodeId?: string;
+      attempt?: number;
+    },
   ): void {
     const binaryToken = normalizeToken(command.binary);
     const binaryName = basename(binaryToken);
@@ -313,6 +352,7 @@ export class SecurityRulesEngine {
     this.assertToolInvocationAllowed({
       tool: binaryName,
       toolClearance,
+      context,
     });
   }
 
diff --git a/src/ui/claude-observability.ts b/src/ui/claude-observability.ts
new file mode 100644
index 0000000..35013b8
--- /dev/null
+++ b/src/ui/claude-observability.ts
@@ -0,0 +1,821 @@
+import { randomUUID } from "node:crypto";
+import { appendFile, mkdir } from "node:fs/promises";
+import { dirname, resolve } from "node:path";
+import type { Options, SDKMessage } from "@anthropic-ai/claude-agent-sdk";
+import type {
+  ClaudeObservabilityMode,
+  ClaudeObservabilityRuntimeConfig,
+  ClaudeObservabilityVerbosity,
+} from "../config.js";
+import type { JsonObject, JsonValue } from "../agents/types.js";
+
+const MAX_STRING_LENGTH = 320;
+const MAX_ARRAY_ITEMS = 20;
+const MAX_OBJECT_KEYS = 60;
+const MAX_DEPTH = 6;
+
+const NON_SECRET_TOKEN_KEYS = new Set([
+  "input_tokens",
+  "output_tokens",
+  "total_tokens",
+  "cache_creation_input_tokens",
+  "cache_read_input_tokens",
+  "ephemeral_1h_input_tokens",
+  "ephemeral_5m_input_tokens",
+  "token_input",
+  "token_output",
+  "token_total",
+  "tokencount",
+  "token_count",
+  "tool_use_id",
+  "parent_tool_use_id",
+  "task_id",
+  "session_id",
+]);
+
+type ClaudeTraceContext = {
+  sessionId: string;
+  nodeId: string;
+  attempt: number;
+  depth: number;
+};
+
+type ClaudeTraceRecord = {
+  id: string;
+  timestamp: string;
+  source: "claude_sdk";
+  stage:
+    | "query.started"
+    | "query.message"
+    | "query.stderr"
+    | "query.completed"
+    | "query.error";
+  message: string;
+  sessionId: string;
+  nodeId: string;
+  attempt: number;
+  depth: number;
+  sdkSessionId?: string;
+  sdkMessageType?: string;
+  sdkMessageSubtype?: string;
+  data?: JsonObject;
+};
+
+function truncate(value: string, maxLength = MAX_STRING_LENGTH): string {
+  if (value.length <= maxLength) {
+    return value;
+  }
+  return `${value.slice(0, maxLength)}...`;
+}
+
+function isSensitiveKey(key: string): boolean {
+  const normalized = key.trim().toLowerCase();
+  if (!normalized) {
+    return false;
+  }
+
+  if (NON_SECRET_TOKEN_KEYS.has(normalized)) {
+    return false;
+  }
+
+  if (/(api[_-]?key|secret|password|authorization|cookie)/i.test(key)) {
+    return true;
+  }
+
+  if (/(auth[_-]?token|access[_-]?token|refresh[_-]?token|id[_-]?token|oauth)/i.test(key)) {
+    return true;
+  }
+
+  return normalized === "token";
+}
+
+function toJsonPrimitive(value: unknown): JsonValue {
+  if (value === null) {
+    return null;
+  }
+  if (typeof value === "string") {
+    return truncate(value);
+  }
+  if (typeof value === "number") {
+    return Number.isFinite(value) ? value : String(value);
+  }
+  if (typeof value === "boolean") {
+    return value;
+  }
+  if (typeof value === "bigint") {
+    return String(value);
+  }
+  if (typeof value === "undefined") {
+    return null;
+  }
+  return truncate(String(value));
+}
+
+function sanitizeJsonValue(value: unknown, depth = 0): JsonValue {
+  if (depth >= MAX_DEPTH) {
+    return "[depth_limit]";
+  }
+
+  if (
+    value === null ||
+    typeof value === "string" ||
+    typeof value === "number" ||
+    typeof value === "boolean" ||
+    typeof value === "bigint" ||
+    typeof value === "undefined"
+  ) {
+    return toJsonPrimitive(value);
+  }
+
+  if (Array.isArray(value)) {
+    const output = value.slice(0, MAX_ARRAY_ITEMS).map((entry) => sanitizeJsonValue(entry, depth + 1));
+    if (value.length > MAX_ARRAY_ITEMS) {
+      output.push(`[+${String(value.length - MAX_ARRAY_ITEMS)} more]`);
+    }
+    return output;
+  }
+
+  if (typeof value === "object") {
+    const output: JsonObject = {};
+    const entries = Object.entries(value as Record<string, unknown>);
+    const limited = entries.slice(0, MAX_OBJECT_KEYS);
+    for (const [key, entryValue] of limited) {
+      if (isSensitiveKey(key)) {
+        output[key] = "[redacted]";
+        continue;
+      }
+      output[key] = sanitizeJsonValue(entryValue, depth + 1);
+    }
+    if (entries.length > MAX_OBJECT_KEYS) {
+      output.__truncated_keys = entries.length - MAX_OBJECT_KEYS;
+    }
+    return output;
+  }
+
+  return truncate(String(value));
+}
+
+function readString(value: unknown): string | undefined {
+  if (typeof value !== "string") {
+    return undefined;
+  }
+  const trimmed = value.trim();
+  return trimmed.length > 0 ? trimmed : undefined;
+}
+
+function readNumber(value: unknown): number | undefined {
+  return typeof value === "number" && Number.isFinite(value) ? value : undefined;
+}
+
+function readBoolean(value: unknown): boolean | undefined {
+  return typeof value === "boolean" ? value : undefined;
+}
+
+function toMessageRecord(message: SDKMessage): Record<string, unknown> {
+  return message as unknown as Record<string, unknown>;
+}
+
+function toMessageSubtype(message: SDKMessage): string | undefined {
+  return readString(toMessageRecord(message).subtype);
+}
+
+function toMessageSessionId(message: SDKMessage): string | undefined {
+  return readString(toMessageRecord(message).session_id);
+}
+
+function toTaskNotificationSummary(message: SDKMessage): {
+  summary: string;
+  data?: JsonObject;
+} {
+  const raw = toMessageRecord(message);
+  const status = readString(raw.status) ?? "unknown";
+  const data: JsonObject = {
+    status,
+  };
+
+  const taskId = readString(raw.task_id);
+  if (taskId) {
+    data.taskId = taskId;
+  }
+
+  const summaryText = readString(raw.summary);
+  if (summaryText) {
+    data.summary = truncate(summaryText);
+  }
+
+  const outputFile = readString(raw.output_file);
+  if (outputFile) {
+    data.outputFile = outputFile;
+  }
+
+  if (raw.usage !== undefined) {
+    data.usage = sanitizeJsonValue(raw.usage);
+  }
+
+  return {
+    summary: `Task notification: ${status}.`,
+    data,
+  };
+}
+
+function toTaskStartedSummary(message: SDKMessage): {
+  summary: string;
+  data?: JsonObject;
+} {
+  const raw = toMessageRecord(message);
+  const data: JsonObject = {};
+
+  const taskId = readString(raw.task_id);
+  if (taskId) {
+    data.taskId = taskId;
+  }
+
+  const description = readString(raw.description);
+  if (description) {
+    data.description = truncate(description);
+  }
+
+  const taskType = readString(raw.task_type);
+  if (taskType) {
+    data.taskType = taskType;
+  }
+
+  const toolUseId = readString(raw.tool_use_id);
+  if (toolUseId) {
+    data.toolUseId = toolUseId;
+  }
+
+  return {
+    summary: "Task started.",
+    ...(Object.keys(data).length > 0 ? { data } : {}),
+  };
+}
+
+function toMessageSummary(message: SDKMessage): {
+  summary: string;
+  data?: JsonObject;
+} {
+  const subtype = toMessageSubtype(message);
+  const raw = toMessageRecord(message);
+
+  if (message.type === "result") {
+    if (message.subtype === "success") {
+      return {
+        summary: "Claude query result success.",
+        data: {
+          stopReason: message.stop_reason ?? null,
+          numTurns: message.num_turns,
+          usage: sanitizeJsonValue(message.usage) as JsonObject,
+          totalCostUsd: message.total_cost_usd,
+        },
+      };
+    }
+
+    return {
+      summary: `Claude query result ${message.subtype}.`,
+      data: {
+        stopReason: message.stop_reason ?? null,
+        numTurns: message.num_turns,
+        usage: sanitizeJsonValue(message.usage) as JsonObject,
+        totalCostUsd: message.total_cost_usd,
+        errors: sanitizeJsonValue(message.errors),
+      },
+    };
+  }
+
+  if (message.type === "tool_progress") {
+    return {
+      summary: `Tool progress: ${message.tool_name}.`,
+      data: {
+        toolName: message.tool_name,
+        toolUseId: message.tool_use_id,
+        elapsedTimeSeconds: message.elapsed_time_seconds,
+        parentToolUseId: message.parent_tool_use_id ?? null,
+        ...(message.task_id ? { taskId: message.task_id } : {}),
+      },
+    };
+  }
+
+  if (message.type === "tool_use_summary") {
+    return {
+      summary: "Tool use summary emitted.",
+      data: {
+        summary: truncate(message.summary),
+        precedingToolUseIds: sanitizeJsonValue(message.preceding_tool_use_ids),
+      },
+    };
+  }
+
+  if (message.type === "stream_event") {
+    const data: JsonObject = {};
+    const eventType = readString((raw.event as Record<string, unknown> | undefined)?.type);
+    if (eventType) {
+      data.eventType = eventType;
+    }
+    const parentToolUseId = readString(raw.parent_tool_use_id);
+    if (parentToolUseId) {
+      data.parentToolUseId = parentToolUseId;
+    }
+    return {
+      summary: "Partial assistant stream event emitted.",
+      ...(Object.keys(data).length > 0 ? { data } : {}),
+    };
+  }
+
+  if (message.type === "auth_status") {
+    return {
+      summary: message.isAuthenticating ? "Authentication in progress." : "Authentication status update.",
+      data: {
+        isAuthenticating: message.isAuthenticating,
+        output: sanitizeJsonValue(message.output),
+        ...(message.error ? { error: truncate(message.error) } : {}),
+      },
+    };
+  }
+
+  if (message.type === "assistant") {
+    return {
+      summary: "Assistant message emitted.",
+      data: {
+        parentToolUseId: message.parent_tool_use_id ?? null,
+        ...(message.error ? { error: message.error } : {}),
+      },
+    };
+  }
+
+  if (message.type === "user") {
+    const data: JsonObject = {
+      parentToolUseId: (message as { parent_tool_use_id?: string | null }).parent_tool_use_id ?? null,
+    };
+    const isSynthetic = readBoolean(raw.isSynthetic);
+    if (isSynthetic !== undefined) {
+      data.isSynthetic = isSynthetic;
+    }
+    const isReplay = readBoolean(raw.isReplay);
+    if (isReplay !== undefined) {
+      data.isReplay = isReplay;
+    }
+    return {
+      summary: "User message emitted.",
+      data,
+    };
+  }
+
+  if (subtype === "task_notification") {
+    return toTaskNotificationSummary(message);
+  }
+
+  if (subtype === "task_started") {
+    return toTaskStartedSummary(message);
+  }
+
+  if (message.type === "system" && subtype === "files_persisted") {
+    const files = Array.isArray(raw.files) ? raw.files : [];
+    const failed = Array.isArray(raw.failed) ? raw.failed : [];
+    return {
+      summary: "System event: files_persisted.",
+      data: {
+        persistedFileCount: files.length,
+        failedFileCount: failed.length,
+      },
+    };
+  }
+
+  if (message.type === "system" && subtype === "compact_boundary") {
+    return {
+      summary: "System event: compact_boundary.",
+      data: {
+        compactMetadata: sanitizeJsonValue(raw.compact_metadata),
+      },
+    };
+  }
+
+  if (message.type === "system" && subtype === "status") {
+    const data: JsonObject = {
+      status: readString(raw.status) ?? "none",
+    };
+    const permissionMode = readString(raw.permissionMode);
+    if (permissionMode) {
+      data.permissionMode = permissionMode;
+    }
+    return {
+      summary: "System event: status.",
+      data,
+    };
+  }
+
+  if (message.type === "system" && (subtype === "hook_started" || subtype === "hook_progress" || subtype === "hook_response")) {
+    const data: JsonObject = {
+      ...(subtype ? { subtype } : {}),
+      ...(readString(raw.hook_id) ? { hookId: readString(raw.hook_id) } : {}),
+      ...(readString(raw.hook_name) ? { hookName: readString(raw.hook_name) } : {}),
+      ...(readString(raw.hook_event) ? { hookEvent: readString(raw.hook_event) } : {}),
+      ...(readString(raw.outcome) ? { outcome: readString(raw.outcome) } : {}),
+    };
+    if (raw.exit_code !== undefined) {
+      data.exitCode = sanitizeJsonValue(raw.exit_code);
+    }
+    return {
+      summary: `System event: ${subtype}.`,
+      data,
+    };
+  }
+
+  if (message.type === "system") {
+    return {
+      summary: subtype ? `System event: ${subtype}.` : "System event emitted.",
+      data: subtype ? { subtype } : undefined,
+    };
+  }
+
+  if (message.type === "rate_limit") {
+    return {
+      summary: "Rate limit event emitted.",
+      data: sanitizeJsonValue(raw) as JsonObject,
+    };
+  }
+
+  if (message.type === "prompt_suggestion") {
+    const data: JsonObject = {
+      ...(readString(raw.prompt) ? { prompt: truncate(readString(raw.prompt) as string) } : {}),
+      ...(readString(raw.suggestion) ? { suggestion: truncate(readString(raw.suggestion) as string) } : {}),
+    };
+    return {
+      summary: "Prompt suggestion emitted.",
+      ...(Object.keys(data).length > 0 ? { data } : {}),
+    };
+  }
+
+  return {
+    summary: `Claude SDK message received (${message.type}).`,
+  };
+}
+
+function toRecord(input: {
+  stage: ClaudeTraceRecord["stage"];
+  message: string;
+  context: ClaudeTraceContext;
+  sdkMessageType?: string;
+  sdkMessageSubtype?: string;
+  sdkSessionId?: string;
+  data?: JsonObject;
+}): ClaudeTraceRecord {
+  return {
+    id: randomUUID(),
+    timestamp: new Date().toISOString(),
+    source: "claude_sdk",
+    stage: input.stage,
+    message: input.message,
+    sessionId: input.context.sessionId,
+    nodeId: input.context.nodeId,
+    attempt: input.context.attempt,
+    depth: input.context.depth,
+    ...(input.sdkMessageType ? { sdkMessageType: input.sdkMessageType } : {}),
+    ...(input.sdkMessageSubtype ? { sdkMessageSubtype: input.sdkMessageSubtype } : {}),
+    ...(input.sdkSessionId ? { sdkSessionId: input.sdkSessionId } : {}),
+    ...(input.data ? { data: input.data } : {}),
+  };
+}
+
+export function summarizeClaudeMessage(
+  message: SDKMessage,
+  verbosity: ClaudeObservabilityVerbosity,
+): {
+  messageType: string;
+  messageSubtype?: string;
+  sdkSessionId?: string;
+  summary: string;
+  data?: JsonObject;
+} {
+  const messageSubtype = toMessageSubtype(message);
+  const sdkSessionId = toMessageSessionId(message);
+  const summary = toMessageSummary(message);
+  if (verbosity === "full") {
+    return {
+      messageType: message.type,
+      ...(messageSubtype ? { messageSubtype } : {}),
+      ...(sdkSessionId ? { sdkSessionId } : {}),
+      summary: summary.summary,
+      data: {
+        message: sanitizeJsonValue(message) as JsonObject,
+      },
+    };
+  }
+
+  return {
+    messageType: message.type,
+    ...(messageSubtype ? { messageSubtype } : {}),
+    ...(sdkSessionId ? { sdkSessionId } : {}),
+    summary: summary.summary,
+    ...(summary.data ? { data: summary.data } : {}),
+  };
+}
+
+export class ClaudeObservabilityLogger {
+  private readonly mode: ClaudeObservabilityMode;
+  private readonly verbosity: ClaudeObservabilityVerbosity;
+  private readonly logPath: string;
+  private readonly includePartialMessages: boolean;
+  private readonly debug: boolean;
+  private readonly debugLogPath?: string;
+  private readonly pendingWrites = new Set<Promise<void>>();
+  private readonly stdoutProgressByKey = new Map<string, {
+    lastEmittedAt: number;
+    suppressed: number;
+  }>();
+  private readonly fileProgressByKey = new Map<string, {
+    lastEmittedAt: number;
+    suppressed: number;
+  }>();
+  private readonly stdoutStreamByKey = new Map<string, {
+    lastEmittedAt: number;
+    suppressed: number;
+  }>();
+  private readonly fileStreamByKey = new Map<string, {
+    lastEmittedAt: number;
+    suppressed: number;
+  }>();
+  private fileWriteFailureCount = 0;
+
+  constructor(input: {
+    workspaceRoot: string;
+    config: ClaudeObservabilityRuntimeConfig;
+  }) {
+    this.mode = input.config.mode;
+    this.verbosity = input.config.verbosity;
+    this.logPath = resolve(input.workspaceRoot, input.config.logPath);
+    this.includePartialMessages = input.config.includePartialMessages;
+    this.debug = input.config.debug;
+    this.debugLogPath = input.config.debugLogPath
+      ? resolve(input.workspaceRoot, input.config.debugLogPath)
+      : undefined;
+  }
+
+  isEnabled(): boolean {
+    return this.mode !== "off";
+  }
+
+  toOptionOverrides(input: {
+    context: ClaudeTraceContext;
+  }): Pick<Options, "includePartialMessages" | "debug" | "debugFile" | "stderr"> {
+    return {
+      includePartialMessages: this.includePartialMessages,
+      debug: this.debug || this.debugLogPath !== undefined,
+      ...(this.debugLogPath ? { debugFile: this.debugLogPath } : {}),
+      stderr: (data: string): void => {
+        this.record({
+          stage: "query.stderr",
+          message: "Claude SDK stderr output.",
+          context: input.context,
+          data: {
+            stderr: sanitizeJsonValue(data),
+          },
+        });
+      },
+    };
+  }
+
+  recordQueryStarted(input: {
+    context: ClaudeTraceContext;
+    data?: JsonObject;
+  }): void {
+    this.record({
+      stage: "query.started",
+      message: "Claude query started.",
+      context: input.context,
+      ...(input.data ? { data: input.data } : {}),
+    });
+  }
+
+  recordMessage(input: {
+    context: ClaudeTraceContext;
+    message: SDKMessage;
+  }): void {
+    const summarized = summarizeClaudeMessage(input.message, this.verbosity);
+    this.record({
+      stage: "query.message",
+      message: summarized.summary,
+      context: input.context,
+      sdkMessageType: summarized.messageType,
+      sdkMessageSubtype: summarized.messageSubtype,
+      sdkSessionId: summarized.sdkSessionId,
+      ...(summarized.data ? { data: summarized.data } : {}),
+    });
+  }
+
+  recordQueryCompleted(input: {
+    context: ClaudeTraceContext;
+    data?: JsonObject;
+  }): void {
+    this.record({
+      stage: "query.completed",
+      message: "Claude query completed.",
+      context: input.context,
+      ...(input.data ? { data: input.data } : {}),
+    });
+  }
+
+  recordQueryError(input: {
+    context: ClaudeTraceContext;
+    error: unknown;
+  }): void {
+    const errorMessage = input.error instanceof Error ? input.error.message : String(input.error);
+    this.record({
+      stage: "query.error",
+      message: "Claude query failed.",
+      context: input.context,
+      data: {
+        error: truncate(errorMessage),
+      },
+    });
+  }
+
+  async close(): Promise<void> {
+    await Promise.all([...this.pendingWrites]);
+  }
+
+  private record(input: {
+    stage: ClaudeTraceRecord["stage"];
+    message: string;
+    context: ClaudeTraceContext;
+    sdkMessageType?: string;
+    sdkMessageSubtype?: string;
+    sdkSessionId?: string;
+    data?: JsonObject;
+  }): void {
+    if (!this.isEnabled()) {
+      return;
+    }
+
+    const record = toRecord(input);
+
+    if (this.mode === "stdout" || this.mode === "both") {
+      const stdoutRecord = this.toStdoutRecord(record);
+      if (stdoutRecord) {
+        console.log(`[claude-trace] ${JSON.stringify(stdoutRecord)}`);
+      }
+    }
+
+    if (this.mode === "file" || this.mode === "both") {
+      const fileRecord = this.toFileRecord(record);
+      if (!fileRecord) {
+        return;
+      }
+      const line = JSON.stringify(fileRecord);
+      const write = mkdir(dirname(this.logPath), { recursive: true })
+        .then(() => appendFile(this.logPath, `${line}\n`, "utf8"))
+        .catch((error: unknown) => {
+          this.reportFileWriteFailure(error);
+        })
+        .finally(() => {
+          this.pendingWrites.delete(write);
+        });
+      this.pendingWrites.add(write);
+    }
+  }
+
+  private toStdoutRecord(record: ClaudeTraceRecord): ClaudeTraceRecord | undefined {
+    return this.toFilteredMessageRecord(record, "stdout");
+  }
+
+  private toFileRecord(record: ClaudeTraceRecord): ClaudeTraceRecord | undefined {
+    return this.toFilteredMessageRecord(record, "file");
+  }
+
+  private toFilteredMessageRecord(
+    record: ClaudeTraceRecord,
+    destination: "stdout" | "file",
+  ): ClaudeTraceRecord | undefined {
+    if (record.stage !== "query.message") {
+      return record;
+    }
+
+    if (!record.sdkMessageType) {
+      return record;
+    }
+
+    if (record.sdkMessageType === "tool_progress") {
+      return this.toSampledToolProgressRecord(record, destination);
+    }
+
+    if (record.sdkMessageType === "stream_event") {
+      if (!this.includePartialMessages) {
+        return undefined;
+      }
+      return this.toSampledStreamEventRecord(record, destination);
+    }
+
+    if (record.sdkMessageType === "auth_status") {
+      const data = record.data;
+      const isAuthenticating = data?.isAuthenticating === true;
+      const hasError = typeof data?.error === "string" && data.error.trim().length > 0;
+      if (hasError || !isAuthenticating) {
+        return record;
+      }
+      return undefined;
+    }
+
+    return record;
+  }
+
+  private toSampledToolProgressRecord(
+    record: ClaudeTraceRecord,
+    destination: "stdout" | "file",
+  ): ClaudeTraceRecord | undefined {
+    const now = Date.now();
+    const minIntervalMs = destination === "stdout" ? 1000 : 2000;
+    const rawToolUseId = record.data?.toolUseId;
+    const toolUseId = typeof rawToolUseId === "string" ? rawToolUseId : "unknown";
+    const key = `${destination}:${record.sessionId}:${record.nodeId}:${toolUseId}`;
+    const progressByKey = destination === "stdout" ? this.stdoutProgressByKey : this.fileProgressByKey;
+    const state = progressByKey.get(key);
+
+    if (!state) {
+      progressByKey.set(key, {
+        lastEmittedAt: now,
+        suppressed: 0,
+      });
+      return record;
+    }
+
+    if (now - state.lastEmittedAt < minIntervalMs) {
+      state.suppressed += 1;
+      return undefined;
+    }
+
+    state.lastEmittedAt = now;
+    const suppressed = state.suppressed;
+    state.suppressed = 0;
+
+    if (suppressed < 1) {
+      return record;
+    }
+
+    const nextData: JsonObject = {
+      ...(record.data ?? {}),
+      suppressedSinceLastEmit: suppressed,
+    };
+
+    return {
+      ...record,
+      data: nextData,
+    };
+  }
+
+  private toSampledStreamEventRecord(
+    record: ClaudeTraceRecord,
+    destination: "stdout" | "file",
+  ): ClaudeTraceRecord | undefined {
+    const now = Date.now();
+    const minIntervalMs = destination === "stdout" ? 700 : 1200;
+    const key = `${destination}:${record.sessionId}:${record.nodeId}:stream`;
+    const streamByKey = destination === "stdout" ? this.stdoutStreamByKey : this.fileStreamByKey;
+    const state = streamByKey.get(key);
+
+    if (!state) {
+      streamByKey.set(key, {
+        lastEmittedAt: now,
+        suppressed: 0,
+      });
+      return record;
+    }
+
+    if (now - state.lastEmittedAt < minIntervalMs) {
+      state.suppressed += 1;
+      return undefined;
+    }
+
+    state.lastEmittedAt = now;
+    const suppressed = state.suppressed;
+    state.suppressed = 0;
+
+    if (suppressed < 1) {
+      return record;
+    }
+
+    const nextData: JsonObject = {
+      ...(record.data ?? {}),
+      suppressedStreamEventsSinceLastEmit: suppressed,
+    };
+
+    return {
+      ...record,
+      data: nextData,
+    };
+  }
+
+  private reportFileWriteFailure(error: unknown): void {
+    this.fileWriteFailureCount += 1;
+    if (this.fileWriteFailureCount <= 5) {
+      const message = error instanceof Error ? error.message : String(error);
+      console.warn(
+        `[claude-trace] failed to append trace log to ${this.logPath}: ${truncate(message, 180)}`,
+      );
+      return;
+    }
+
+    if (this.fileWriteFailureCount === 6) {
+      console.warn("[claude-trace] additional trace-log write failures suppressed.");
+    }
+  }
+}
diff --git a/src/ui/claude-trace-store.ts b/src/ui/claude-trace-store.ts
new file mode 100644
index 0000000..7ff0bd9
--- /dev/null
+++ b/src/ui/claude-trace-store.ts
@@ -0,0 +1,85 @@
+import { readFile } from "node:fs/promises";
+import { resolve } from "node:path";
+
+export type ClaudeTraceEvent = {
+  timestamp: string;
+  message: string;
+  stage?: string;
+  sessionId?: string;
+  sdkMessageType?: string;
+  sdkMessageSubtype?: string;
+  data?: unknown;
+} & Record<string, unknown>;
+
+type ClaudeTraceFilter = {
+  sessionId?: string;
+  limit?: number;
+};
+
+function safeParseLine(line: string): ClaudeTraceEvent | undefined {
+  const trimmed = line.trim();
+  if (!trimmed) {
+    return undefined;
+  }
+
+  try {
+    const parsed = JSON.parse(trimmed) as unknown;
+    if (!parsed || typeof parsed !== "object") {
+      return undefined;
+    }
+
+    const record = parsed as Record<string, unknown>;
+    if (typeof record.timestamp !== "string" || typeof record.message !== "string") {
+      return undefined;
+    }
+
+    return record as ClaudeTraceEvent;
+  } catch {
+    return undefined;
+  }
+}
+
+export async function readClaudeTraceEvents(logPath: string): Promise<ClaudeTraceEvent[]> {
+  const absolutePath = resolve(logPath);
+  let content = "";
+
+  try {
+    content = await readFile(absolutePath, "utf8");
+  } catch (error) {
+    if ((error as NodeJS.ErrnoException).code === "ENOENT") {
+      return [];
+    }
+    throw error;
+  }
+
+  const parsed: ClaudeTraceEvent[] = [];
+  for (const line of content.split(/\r?\n/)) {
+    const event = safeParseLine(line);
+    if (event) {
+      parsed.push(event);
+    }
+  }
+
+  parsed.sort((left, right) => left.timestamp.localeCompare(right.timestamp));
+  return parsed;
+}
+
+export function filterClaudeTraceEvents(
+  events: readonly ClaudeTraceEvent[],
+  filter: ClaudeTraceFilter,
+): ClaudeTraceEvent[] {
+  const filtered: ClaudeTraceEvent[] = [];
+
+  for (const event of events) {
+    if (filter.sessionId && event.sessionId !== filter.sessionId) {
+      continue;
+    }
+    filtered.push(event);
+  }
+
+  if (!filter.limit || filter.limit < 1 || filtered.length <= filter.limit) {
+    return filtered;
+  }
+
+  return filtered.slice(-filter.limit);
+}
diff --git a/src/ui/config-store.ts b/src/ui/config-store.ts
index 222eab9..fd245a9 100644
--- a/src/ui/config-store.ts
+++ b/src/ui/config-store.ts
@@ -39,6 +39,7 @@ export type UiConfigSnapshot = {
     stateRoot: string;
     projectContextPath: string;
     runtimeEventLogPath: string;
+    claudeTraceLogPath: string;
     securityAuditLogPath: string;
   };
 };
@@ -107,6 +108,7 @@ function toSnapshot(config: Readonly<AppConfig>, envFilePath: string): UiConfigS
       stateRoot: config.orchestration.stateRoot,
       projectContextPath: config.orchestration.projectContextPath,
       runtimeEventLogPath: config.runtimeEvents.logPath,
+      claudeTraceLogPath: config.provider.claudeObservability.logPath,
       securityAuditLogPath: config.security.auditLogPath,
     },
   };
diff --git a/src/ui/provider-executor.ts b/src/ui/provider-executor.ts
index de5a9c9..c43ddf3 100644
--- a/src/ui/provider-executor.ts
+++ b/src/ui/provider-executor.ts
@@ -10,6 +10,7 @@ import { isDomainEventType, type DomainEventEmission } from "../agents/domain-ev
 import type { ActorExecutionInput, ActorExecutionResult, ActorExecutor } from "../agents/pipeline.js";
 import { isRecord, type JsonObject, type JsonValue } from "../agents/types.js";
 import { createSessionContext, type SessionContext } from "../examples/session-context.js";
+import { ClaudeObservabilityLogger } from "./claude-observability.js";
 
 export type RunProvider = "codex" | "claude";
 
@@ -17,6 +18,7 @@ export type ProviderRunRuntime = {
   provider: RunProvider;
   config: Readonly<AppConfig>;
   sessionContext: SessionContext;
+  claudeObservability: ClaudeObservabilityLogger;
   close: () => Promise<void>;
 };
 
@@ -416,6 +418,40 @@ type ClaudeTurnResult = {
   usage: ProviderUsage;
 };
 
+function toClaudeTraceContext(actorInput: ActorExecutionInput): {
+  sessionId: string;
+  nodeId: string;
+  attempt: number;
+  depth: number;
+} {
+  return {
+    sessionId: actorInput.sessionId,
+    nodeId: actorInput.node.id,
+    attempt: actorInput.attempt,
+    depth: actorInput.depth,
+  };
+}
+
+function toProviderUsageJson(usage: ProviderUsage): JsonObject {
+  const output: JsonObject = {};
+  if (typeof usage.tokenInput === "number") {
+    output.tokenInput = usage.tokenInput;
+  }
+  if (typeof usage.tokenOutput === "number") {
+    output.tokenOutput = usage.tokenOutput;
+  }
+  if (typeof usage.tokenTotal === "number") {
+    output.tokenTotal = usage.tokenTotal;
+  }
+  if (typeof usage.durationMs === "number") {
+    output.durationMs = usage.durationMs;
+  }
+  if (typeof usage.costUsd === "number") {
+    output.costUsd = usage.costUsd;
+  }
+  return output;
+}
+
 function buildClaudeOptions(input: {
   runtime: ProviderRunRuntime;
   actorInput: ActorExecutionInput;
@@ -433,6 +469,7 @@ function buildClaudeOptions(input: {
     ...runtime.sessionContext.runtimeInjection.env,
     ...buildClaudeAuthEnv(runtime.config.provider),
   };
+  const traceContext = toClaudeTraceContext(actorInput);
 
   return {
     maxTurns: CLAUDE_PROVIDER_MAX_TURNS,
@@ -449,6 +486,9 @@ function buildClaudeOptions(input: {
     canUseTool: actorInput.mcp.createClaudeCanUseTool(),
     cwd: runtime.sessionContext.runtimeInjection.workingDirectory,
     env: runtimeEnv,
+    ...runtime.claudeObservability.toOptionOverrides({
+      context: traceContext,
+    }),
     outputFormat: CLAUDE_OUTPUT_FORMAT,
   };
 }
@@ -458,10 +498,19 @@ async function runClaudeTurn(input: {
   actorInput: ActorExecutionInput;
   prompt: string;
 }): Promise<ClaudeTurnResult> {
+  const traceContext = toClaudeTraceContext(input.actorInput);
   const options = buildClaudeOptions({
     runtime: input.runtime,
     actorInput: input.actorInput,
   });
+  input.runtime.claudeObservability.recordQueryStarted({
+    context: traceContext,
+    data: {
+      ...(options.model ? { model: options.model } : {}),
+      maxTurns: options.maxTurns ?? CLAUDE_PROVIDER_MAX_TURNS,
+      cwd: input.runtime.sessionContext.runtimeInjection.workingDirectory,
+    },
+  });
 
   const startedAt = Date.now();
   const stream = query({
@@ -472,6 +521,7 @@ async function runClaudeTurn(input: {
   let resultText = "";
   let structuredOutput: unknown;
   let usage: ProviderUsage = {};
+  let messageCount = 0;
 
   const onAbort = (): void => {
     stream.close();
@@ -481,6 +531,12 @@ async function runClaudeTurn(input: {
 
   try {
     for await (const message of stream as AsyncIterable<SDKMessage>) {
+      messageCount += 1;
+      input.runtime.claudeObservability.recordMessage({
+        context: traceContext,
+        message,
+      });
+
       if (message.type !== "result") {
         continue;
       }
@@ -502,6 +558,12 @@ async function runClaudeTurn(input: {
         costUsd: message.total_cost_usd,
       };
     }
+  } catch (error) {
+    input.runtime.claudeObservability.recordQueryError({
+      context: traceContext,
+      error,
+    });
+    throw error;
   } finally {
     input.actorInput.signal.removeEventListener("abort", onAbort);
     stream.close();
@@ -512,9 +574,22 @@ async function runClaudeTurn(input: {
   }
 
   if (!resultText) {
-    throw new Error("Claude run completed without a final result.");
+    const error = new Error("Claude run completed without a final result.");
+    input.runtime.claudeObservability.recordQueryError({
+      context: traceContext,
+      error,
+    });
+    throw error;
   }
 
+  input.runtime.claudeObservability.recordQueryCompleted({
+    context: traceContext,
+    data: {
+      messageCount,
+      usage: toProviderUsageJson(usage),
+    },
+  });
+
   return {
     text: resultText,
     structuredOutput,
@@ -554,19 +629,29 @@ export async function createProviderRunRuntime(input: {
   initialPrompt: string;
   config: Readonly<AppConfig>;
   projectPath: string;
+  observabilityRootPath?: string;
 }): Promise<ProviderRunRuntime> {
   const sessionContext = await createSessionContext(input.provider, {
     prompt: input.initialPrompt,
     config: input.config,
     workspaceRoot: input.projectPath,
   });
+  const claudeObservability = new ClaudeObservabilityLogger({
+    workspaceRoot: input.observabilityRootPath ?? input.projectPath,
+    config: input.config.provider.claudeObservability,
+  });
 
   return {
     provider: input.provider,
     config: input.config,
     sessionContext,
+    claudeObservability,
     close: async () => {
-      await sessionContext.close();
+      try {
+        await sessionContext.close();
+      } finally {
+        await claudeObservability.close();
+      }
     },
   };
 }
diff --git a/src/ui/public/app.js b/src/ui/public/app.js
index f52e67d..009e21b 100644
--- a/src/ui/public/app.js
+++ b/src/ui/public/app.js
@@ -39,6 +39,9 @@ const dom = {
   eventsLimit: document.querySelector("#events-limit"),
   eventsRefresh: document.querySelector("#events-refresh"),
   eventFeed: document.querySelector("#event-feed"),
+  claudeEventsLimit: document.querySelector("#claude-events-limit"),
+  claudeEventsRefresh: document.querySelector("#claude-events-refresh"),
+  claudeEventFeed: document.querySelector("#claude-event-feed"),
   historyRefresh: document.querySelector("#history-refresh"),
   historyBody: document.querySelector("#history-body"),
   notificationsForm: document.querySelector("#notifications-form"),
@@ -147,6 +150,7 @@ const LABEL_HELP_BY_CONTROL = Object.freeze({
   "session-project-path": "Absolute project path used when creating an explicit managed session.",
   "session-close-merge": "When enabled, close will merge the session base branch back into the project branch.",
   "events-limit": "Set how many recent runtime events are loaded per refresh.",
+  "claude-events-limit": "Set how many Claude SDK trace records are loaded per refresh.",
   "cfg-webhook-url": "Webhook endpoint that receives runtime event notifications.",
   "cfg-webhook-severity": "Minimum severity level that triggers webhook notifications.",
   "cfg-webhook-always": "Event types that should always notify, regardless of severity.",
@@ -1493,6 +1497,43 @@ function renderEventFeed(events) {
   dom.eventFeed.innerHTML = rows || '<div class="event-row"><div class="event-time">-</div><div class="event-type">-</div><div>No runtime events.</div></div>';
 }
 
+function toClaudeRowSeverity(event) {
+  const stage = String(event?.stage || "");
+  const type = String(event?.sdkMessageType || "");
+  if (stage === "query.error") {
+    return "critical";
+  }
+  if (stage === "query.stderr" || (type === "result" && String(event?.sdkMessageSubtype || "").startsWith("error_"))) {
+    return "warning";
+  }
+  return "info";
+}
+
+function renderClaudeTraceFeed(events) {
+  const rows = [...events]
+    .reverse()
+    .map((event) => {
+      const ts = new Date(event.timestamp).toLocaleTimeString();
+      const stage = String(event.stage || "query.message");
+      const sdkMessageType = String(event.sdkMessageType || "");
+      const sdkMessageSubtype = String(event.sdkMessageSubtype || "");
+      const typeLabel = sdkMessageType
+        ? `${stage}/${sdkMessageType}${sdkMessageSubtype ? `:${sdkMessageSubtype}` : ""}`
+        : stage;
+      const message = typeof event.message === "string" ? event.message : JSON.stringify(event.message || "");
+      return `
+        <div class="event-row ${escapeHtml(toClaudeRowSeverity(event))}">
+          <div class="event-time">${escapeHtml(ts)}</div>
+          <div class="event-type">${escapeHtml(typeLabel)}</div>
+          <div>${escapeHtml(message)}</div>
+        </div>
+      `;
+    })
+    .join("");
+
+  dom.claudeEventFeed.innerHTML = rows || '<div class="event-row"><div class="event-time">-</div><div class="event-type">-</div><div>No Claude trace events.</div></div>';
+}
+
 async function refreshEvents() {
   const limit = Number(dom.eventsLimit.value || "150");
   const params = new URLSearchParams({
@@ -1507,6 +1548,20 @@ async function refreshEvents() {
   renderEventFeed(payload.events || []);
 }
 
+async function refreshClaudeTrace() {
+  const limit = Number(dom.claudeEventsLimit.value || "150");
+  const params = new URLSearchParams({
+    limit: String(limit),
+  });
+
+  if (state.selectedSessionId) {
+    params.set("sessionId", state.selectedSessionId);
+  }
+
+  const payload = await apiRequest(`/api/claude-trace?${params.toString()}`);
+  renderClaudeTraceFeed(payload.events || []);
+}
+
 async function startRun(event) {
   event.preventDefault();
 
@@ -1581,6 +1636,7 @@ async function startRun(event) {
     dom.sessionSelect.value = run.sessionId;
     await refreshGraph();
     await refreshEvents();
+    await refreshClaudeTrace();
   } catch (error) {
     showRunStatus(error instanceof Error ? error.message : String(error), true);
   }
@@ -1601,6 +1657,7 @@ async function cancelActiveRun() {
     await loadSessions();
     await refreshGraph();
     await refreshEvents();
+    await refreshClaudeTrace();
   } catch (error) {
     showRunStatus(error instanceof Error ? error.message : String(error), true);
   }
@@ -1633,6 +1690,7 @@ async function createSessionFromUi() {
       dom.sessionSelect.value = state.selectedSessionId;
       await refreshGraph();
       await refreshEvents();
+      await refreshClaudeTrace();
     }
   } catch (error) {
     showRunStatus(error instanceof Error ? error.message : String(error), true);
@@ -1659,6 +1717,7 @@ async function closeSelectedSessionFromUi() {
     await loadSessions();
     await refreshGraph();
     await refreshEvents();
+    await refreshClaudeTrace();
   } catch (error) {
     showRunStatus(error instanceof Error ? error.message : String(error), true);
   }
@@ -1808,6 +1867,7 @@ function bindUiEvents() {
     state.selectedSessionId = dom.sessionSelect.value;
     await refreshGraph();
     await refreshEvents();
+    await refreshClaudeTrace();
   });
 
   dom.graphManifestSelect.addEventListener("change", async () => {
@@ -1827,9 +1887,14 @@ function bindUiEvents() {
     await refreshEvents();
   });
 
+  dom.claudeEventsRefresh.addEventListener("click", async () => {
+    await refreshClaudeTrace();
+  });
+
   dom.historyRefresh.addEventListener("click", async () => {
     await loadSessions();
     await refreshGraph();
+    await refreshClaudeTrace();
   });
 
   dom.runForm.addEventListener("submit", startRun);
@@ -1949,6 +2014,7 @@ async function refreshAll() {
 
   await refreshGraph();
   await refreshEvents();
+  await refreshClaudeTrace();
 }
 
 async function initialize() {
@@ -1979,6 +2045,10 @@ async function initialize() {
     void refreshEvents();
   }, 3000);
 
+  setInterval(() => {
+    void refreshClaudeTrace();
+  }, 3000);
+
   setInterval(() => {
     void refreshGraph();
   }, 7000);
diff --git a/src/ui/public/index.html b/src/ui/public/index.html
index f701f0d..7a48404 100644
--- a/src/ui/public/index.html
+++ b/src/ui/public/index.html
@@ -130,6 +130,24 @@
           <div id="event-feed" class="event-feed"></div>
         </section>
 
+        <section class="panel claude-panel">
+          <div class="panel-head">
+            <h2>Claude Trace</h2>
+            <div class="panel-actions">
+              <label>
+                Limit
+                <select id="claude-events-limit">
+                  <option value="80">80</option>
+                  <option value="150" selected>150</option>
+                  <option value="300">300</option>
+                </select>
+              </label>
+              <button id="claude-events-refresh" type="button">Refresh</button>
+            </div>
+          </div>
+          <div id="claude-event-feed" class="event-feed claude-event-feed"></div>
+        </section>
+
         <section class="panel history-panel">
           <div class="panel-head">
             <h2>Run History</h2>
diff --git a/src/ui/public/styles.css b/src/ui/public/styles.css
index eb9012d..fd5af89 100644
--- a/src/ui/public/styles.css
+++ b/src/ui/public/styles.css
@@ -79,7 +79,8 @@ p {
   grid-template-columns: minmax(0, 2fr) minmax(280px, 1fr);
   grid-template-areas:
     "graph side"
-    "feed history"
+    "feed claude"
+    "history history"
     "config config";
 }
 
@@ -129,6 +130,10 @@ p {
   grid-area: history;
 }
 
+.claude-panel {
+  grid-area: claude;
+}
+
 .config-panel {
   grid-area: config;
 }
@@ -314,6 +319,14 @@ button.danger {
   color: var(--critical);
 }
 
+.claude-event-feed .event-row {
+  grid-template-columns: 110px 150px 1fr;
+}
+
+.claude-event-feed .event-type {
+  font-size: 0.7rem;
+}
+
 .history-table {
   width: 100%;
   border-collapse: collapse;
@@ -485,6 +498,7 @@ button.danger {
       "graph"
       "side"
       "feed"
+      "claude"
       "history"
       "config";
   }
diff --git a/src/ui/run-service.ts b/src/ui/run-service.ts
index 889be32..59012a1 100644
--- a/src/ui/run-service.ts
+++ b/src/ui/run-service.ts
@@ -488,6 +488,7 @@ export class UiRunService {
             initialPrompt: input.prompt,
             config,
             projectPath: session?.baseWorkspacePath ?? this.workspaceRoot,
+            observabilityRootPath: this.workspaceRoot,
           });
         }
 
diff --git a/src/ui/server.ts b/src/ui/server.ts
index 84bb4a5..e5790c5 100644
--- a/src/ui/server.ts
+++ b/src/ui/server.ts
@@ -6,6 +6,7 @@ import { buildSessionGraphInsight, buildSessionSummaries } from "./session-insig
 import { UiConfigStore, type LimitSettings, type RuntimeNotificationSettings, type SecurityPolicySettings } from "./config-store.js";
 import { ManifestStore } from "./manifest-store.js";
 import { filterRuntimeEvents, readRuntimeEvents } from "./runtime-events-store.js";
+import { filterClaudeTraceEvents, readClaudeTraceEvents } from "./claude-trace-store.js";
 import { parseJsonBody, sendJson, methodNotAllowed, notFound, serveStaticFile } from "./http-utils.js";
 import { readRunMetaBySession, UiRunService, type RunExecutionMode } from "./run-service.js";
 import type { RunProvider } from "./provider-executor.js";
@@ -120,11 +121,13 @@ function ensureNonEmptyString(value: unknown, field: string): string {
 async function readRuntimePaths(configStore: UiConfigStore, workspaceRoot: string): Promise<{
   stateRoot: string;
   runtimeEventLogPath: string;
+  claudeTraceLogPath: string;
 }> {
   const snapshot = await configStore.readSnapshot();
   return {
     stateRoot: resolve(workspaceRoot, snapshot.paths.stateRoot),
     runtimeEventLogPath: resolve(workspaceRoot, snapshot.paths.runtimeEventLogPath),
+    claudeTraceLogPath: resolve(workspaceRoot, snapshot.paths.claudeTraceLogPath),
   };
 }
 
@@ -313,6 +316,27 @@ async function handleApiRequest(input: {
       return true;
     }
 
+    if (pathname === "/api/claude-trace") {
+      if (method !== "GET") {
+        methodNotAllowed(response);
+        return true;
+      }
+
+      const { claudeTraceLogPath } = await readRuntimePaths(configStore, workspaceRoot);
+      const limit = parseLimit(requestUrl.searchParams.get("limit"), 200);
+      const sessionId = requestUrl.searchParams.get("sessionId") ?? undefined;
+      const events = filterClaudeTraceEvents(await readClaudeTraceEvents(claudeTraceLogPath), {
+        ...(sessionId ? { sessionId } : {}),
+        limit,
+      });
+
+      sendJson(response, 200, {
+        ok: true,
+        events,
+      });
+      return true;
+    }
+
     if (pathname === "/api/sessions") {
       if (method === "POST") {
         const body = await parseJsonBody<CreateSessionRequest>(request);
diff --git a/tests/claude-observability.test.ts b/tests/claude-observability.test.ts
new file mode 100644
index 0000000..c450948
--- /dev/null
+++ b/tests/claude-observability.test.ts
@@ -0,0 +1,296 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { mkdtemp, readFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import type { SDKMessage } from "@anthropic-ai/claude-agent-sdk";
+import { ClaudeObservabilityLogger, summarizeClaudeMessage } from "../src/ui/claude-observability.js";
+
+test("summarizeClaudeMessage returns compact result metadata in summary mode", () => {
+  const message = {
+    type: "result",
+    subtype: "success",
+    stop_reason: "end_turn",
+    num_turns: 1,
+    total_cost_usd: 0.0012,
+    usage: {
+      input_tokens: 120,
+      output_tokens: 40,
+    },
+    result: "{\"status\":\"success\"}",
+    duration_ms: 40,
+    duration_api_ms: 32,
+    is_error: false,
+    modelUsage: {},
+    permission_denials: [],
+    uuid: "uuid-1",
+    session_id: "sdk-session-1",
+  } as unknown as SDKMessage;
+
+  const summary = summarizeClaudeMessage(message, "summary");
+
+  assert.equal(summary.messageType, "result");
+  assert.equal(summary.messageSubtype, "success");
+  assert.equal(summary.sdkSessionId, "sdk-session-1");
+  assert.equal(summary.summary, "Claude query result success.");
+  assert.equal(summary.data?.numTurns, 1);
+  const usage = summary.data?.usage as Record<string, unknown> | undefined;
+  assert.equal(usage?.input_tokens, 120);
+});
+
+test("summarizeClaudeMessage redacts sensitive fields in full mode", () => {
+  const message = {
+    type: "system",
+    subtype: "init",
+    session_id: "sdk-session-2",
+    uuid: "uuid-2",
+    apiKey: "top-secret",
+    nested: {
+      authToken: "really-secret",
+      ok: true,
+    },
+  } as unknown as SDKMessage;
+
+  const summary = summarizeClaudeMessage(message, "full");
+  const payload = summary.data?.message as Record<string, unknown> | undefined;
+  const nested = payload?.nested as Record<string, unknown> | undefined;
+
+  assert.equal(summary.messageType, "system");
+  assert.equal(summary.messageSubtype, "init");
+  assert.equal(payload?.apiKey, "[redacted]");
+  assert.equal(nested?.authToken, "[redacted]");
+  assert.equal(nested?.ok, true);
+});
+
+test("ClaudeObservabilityLogger samples tool_progress messages for stdout", () => {
+  const lines: string[] = [];
+  const originalLog = console.log;
+  const originalNow = Date.now;
+  let now = 1000;
+
+  console.log = (line?: unknown) => {
+    lines.push(String(line ?? ""));
+  };
+  Date.now = () => now;
+
+  try {
+    const logger = new ClaudeObservabilityLogger({
+      workspaceRoot: process.cwd(),
+      config: {
+        mode: "stdout",
+        verbosity: "summary",
+        logPath: ".ai_ops/events/claude-trace.ndjson",
+        includePartialMessages: false,
+        debug: false,
+      },
+    });
+
+    const context = {
+      sessionId: "session-a",
+      nodeId: "node-a",
+      attempt: 1,
+      depth: 0,
+    };
+
+    const makeMessage = (): SDKMessage =>
+      ({
+        type: "tool_progress",
+        tool_name: "Bash",
+        tool_use_id: "tool-1",
+        parent_tool_use_id: null,
+        elapsed_time_seconds: 1,
+        uuid: "uuid-tool",
+        session_id: "sdk-session-tool",
+      }) as unknown as SDKMessage;
+
+    logger.recordMessage({
+      context,
+      message: makeMessage(),
+    });
+
+    now += 300;
+    logger.recordMessage({
+      context,
+      message: makeMessage(),
+    });
+
+    now += 1200;
+    logger.recordMessage({
+      context,
+      message: makeMessage(),
+    });
+
+    assert.equal(lines.length, 2);
+    assert.match(lines[0] ?? "", /^\[claude-trace\] /);
+    assert.match(lines[1] ?? "", /"suppressedSinceLastEmit":1/);
+  } finally {
+    console.log = originalLog;
+    Date.now = originalNow;
+  }
+});
+
+test("ClaudeObservabilityLogger keeps assistant/user message records in file output", async () => {
+  const workspace = await mkdtemp(join(tmpdir(), "claude-obsv-test-"));
+  const logPath = ".ai_ops/events/claude-trace.ndjson";
+  const logger = new ClaudeObservabilityLogger({
+    workspaceRoot: workspace,
+    config: {
+      mode: "file",
+      verbosity: "summary",
+      logPath,
+      includePartialMessages: false,
+      debug: false,
+    },
+  });
+
+  const context = {
+    sessionId: "session-file",
+    nodeId: "node-file",
+    attempt: 1,
+    depth: 0,
+  };
+
+  logger.recordQueryStarted({
+    context,
+  });
+  logger.recordMessage({
+    context,
+    message: {
+      type: "assistant",
+      uuid: "assistant-1",
+      session_id: "sdk-file-1",
+      parent_tool_use_id: null,
+      message: {} as never,
+    } as unknown as SDKMessage,
+  });
+  logger.recordMessage({
+    context,
+    message: {
+      type: "user",
+      uuid: "user-1",
+      session_id: "sdk-file-1",
+      parent_tool_use_id: null,
+      message: {} as never,
+    } as unknown as SDKMessage,
+  });
+  logger.recordMessage({
+    context,
+    message: {
+      type: "result",
+      subtype: "success",
+      stop_reason: "end_turn",
+      num_turns: 1,
+      total_cost_usd: 0.0012,
+      usage: {
+        input_tokens: 100,
+        output_tokens: 20,
+      },
+      result: "{}",
+      duration_ms: 10,
+      duration_api_ms: 9,
+      is_error: false,
+      modelUsage: {},
+      permission_denials: [],
+      uuid: "result-1",
+      session_id: "sdk-file-1",
+    } as unknown as SDKMessage,
+  });
+  logger.recordQueryCompleted({
+    context,
+  });
+
+  await logger.close();
+
+  const filePath = join(workspace, logPath);
+  const content = await readFile(filePath, "utf8");
+  const lines = content.split(/\r?\n/).filter((line) => line.trim().length > 0);
+  const records = lines.map((line) => JSON.parse(line) as Record<string, unknown>);
+  const messageTypes = records
+    .map((record) => record.sdkMessageType)
+    .filter((value) => typeof value === "string");
+
+  assert.equal(messageTypes.includes("assistant"), true);
+  assert.equal(messageTypes.includes("user"), true);
+  assert.equal(messageTypes.includes("result"), true);
+});
+
+test("summarizeClaudeMessage maps task_notification system subtype", () => {
+  const message = {
+    type: "system",
+    subtype: "task_notification",
+    task_id: "task-1",
+    status: "completed",
+    output_file: "/tmp/out.txt",
+    summary: "Task complete",
+    uuid: "uuid-task",
+    session_id: "sdk-session-task",
+  } as unknown as SDKMessage;
+
+  const summary = summarizeClaudeMessage(message, "summary");
+
+  assert.equal(summary.messageType, "system");
+  assert.equal(summary.messageSubtype, "task_notification");
+  assert.equal(summary.summary, "Task notification: completed.");
+  assert.equal(summary.data?.taskId, "task-1");
+});
+
+test("ClaudeObservabilityLogger honors includePartialMessages for stream events", () => {
+  const lines: string[] = [];
+  const originalLog = console.log;
+  console.log = (line?: unknown) => {
+    lines.push(String(line ?? ""));
+  };
+
+  try {
+    const context = {
+      sessionId: "session-stream",
+      nodeId: "node-stream",
+      attempt: 1,
+      depth: 0,
+    };
+    const streamMessage = {
+      type: "stream_event",
+      event: {
+        type: "content_block_delta",
+      },
+      parent_tool_use_id: null,
+      uuid: "stream-1",
+      session_id: "sdk-session-stream",
+    } as unknown as SDKMessage;
+
+    const withoutPartial = new ClaudeObservabilityLogger({
+      workspaceRoot: process.cwd(),
+      config: {
+        mode: "stdout",
+        verbosity: "summary",
+        logPath: ".ai_ops/events/claude-trace.ndjson",
+        includePartialMessages: false,
+        debug: false,
+      },
+    });
+    withoutPartial.recordMessage({
+      context,
+      message: streamMessage,
+    });
+
+    const withPartial = new ClaudeObservabilityLogger({
+      workspaceRoot: process.cwd(),
+      config: {
+        mode: "stdout",
+        verbosity: "summary",
+        logPath: ".ai_ops/events/claude-trace.ndjson",
+        includePartialMessages: true,
+        debug: false,
+      },
+    });
+    withPartial.recordMessage({
+      context,
+      message: streamMessage,
+    });
+
+    assert.equal(lines.length, 1);
+    assert.match(lines[0] ?? "", /\"sdkMessageType\":\"stream_event\"/);
+  } finally {
+    console.log = originalLog;
+  }
+});
diff --git a/tests/claude-trace-store.test.ts b/tests/claude-trace-store.test.ts
new file mode 100644
index 0000000..cf65efe
--- /dev/null
+++ b/tests/claude-trace-store.test.ts
@@ -0,0 +1,42 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { mkdtemp, writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { filterClaudeTraceEvents, readClaudeTraceEvents } from "../src/ui/claude-trace-store.js";
+
+test("readClaudeTraceEvents parses and sorts ndjson records", async () => {
+  const workspace = await mkdtemp(join(tmpdir(), "claude-trace-store-"));
+  const logPath = join(workspace, "claude-trace.ndjson");
+  await writeFile(
+    logPath,
+    [
+      '{"timestamp":"2026-02-24T17:27:05.000Z","message":"later","sessionId":"s1"}',
+      'not-json',
+      '{"timestamp":"2026-02-24T17:26:00.000Z","message":"earlier","sessionId":"s1"}',
+      '{"message":"missing timestamp"}',
+    ].join("\n"),
+    "utf8",
+  );
+
+  const events = await readClaudeTraceEvents(logPath);
+  assert.equal(events.length, 2);
+  assert.equal(events[0]?.message, "earlier");
+  assert.equal(events[1]?.message, "later");
+});
+
+test("filterClaudeTraceEvents filters by session and limit", () => {
+  const events = [
+    { timestamp: "2026-02-24T17:00:00.000Z", message: "a", sessionId: "s1" },
+    { timestamp: "2026-02-24T17:01:00.000Z", message: "b", sessionId: "s2" },
+    { timestamp: "2026-02-24T17:02:00.000Z", message: "c", sessionId: "s1" },
+  ];
+
+  const filtered = filterClaudeTraceEvents(events, {
+    sessionId: "s1",
+    limit: 1,
+  });
+
+  assert.equal(filtered.length, 1);
+  assert.equal(filtered[0]?.message, "c");
+});
diff --git a/tests/config.test.ts b/tests/config.test.ts
index 1de9677..a25c7dc 100644
--- a/tests/config.test.ts
+++ b/tests/config.test.ts
@@ -25,6 +25,11 @@ test("loads defaults and freezes config", () => {
     "session.failed",
   ]);
   assert.equal(config.provider.openAiAuthMode, "auto");
+  assert.equal(config.provider.claudeObservability.mode, "off");
+  assert.equal(config.provider.claudeObservability.verbosity, "summary");
+  assert.equal(config.provider.claudeObservability.logPath, ".ai_ops/events/claude-trace.ndjson");
+  assert.equal(config.provider.claudeObservability.includePartialMessages, false);
+  assert.equal(config.provider.claudeObservability.debug, false);
   assert.equal(Object.isFrozen(config), true);
   assert.equal(Object.isFrozen(config.orchestration), true);
 });
@@ -57,6 +62,38 @@ test("validates runtime discord severity mode", () => {
   );
 });
 
+test("validates claude observability mode", () => {
+  assert.throws(
+    () => loadConfig({ CLAUDE_OBSERVABILITY_MODE: "stream" }),
+    /CLAUDE_OBSERVABILITY_MODE must be one of/,
+  );
+});
+
+test("validates claude observability verbosity", () => {
+  assert.throws(
+    () => loadConfig({ CLAUDE_OBSERVABILITY_VERBOSITY: "verbose" }),
+    /CLAUDE_OBSERVABILITY_VERBOSITY must be one of/,
+  );
+});
+
+test("loads claude observability settings", () => {
+  const config = loadConfig({
+    CLAUDE_OBSERVABILITY_MODE: "both",
+    CLAUDE_OBSERVABILITY_VERBOSITY: "full",
+    CLAUDE_OBSERVABILITY_LOG_PATH: ".ai_ops/debug/claude.ndjson",
+    CLAUDE_OBSERVABILITY_INCLUDE_PARTIAL: "true",
+    CLAUDE_OBSERVABILITY_DEBUG: "true",
+    CLAUDE_OBSERVABILITY_DEBUG_LOG_PATH: ".ai_ops/debug/claude-sdk.log",
+  });
+
+  assert.equal(config.provider.claudeObservability.mode, "both");
+  assert.equal(config.provider.claudeObservability.verbosity, "full");
+  assert.equal(config.provider.claudeObservability.logPath, ".ai_ops/debug/claude.ndjson");
+  assert.equal(config.provider.claudeObservability.includePartialMessages, true);
+  assert.equal(config.provider.claudeObservability.debug, true);
+  assert.equal(config.provider.claudeObservability.debugLogPath, ".ai_ops/debug/claude-sdk.log");
+});
+
 test("prefers CLAUDE_CODE_OAUTH_TOKEN over ANTHROPIC_API_KEY", () => {
   const config = loadConfig({
     CLAUDE_CODE_OAUTH_TOKEN: "oauth-token",
diff --git a/tests/security-middleware.test.ts b/tests/security-middleware.test.ts
index a1ce4c8..fc77b07 100644
--- a/tests/security-middleware.test.ts
+++ b/tests/security-middleware.test.ts
@@ -155,3 +155,41 @@ test("secure executor runs with explicit env policy", async () => {
   assert.equal(result.stdout, "ok|\n");
   assert.equal(streamedStdout, result.stdout);
 });
+
+test("rules engine carries session context in tool audit events", () => {
+  const events: Array<Record<string, unknown>> = [];
+  const rules = new SecurityRulesEngine(
+    {
+      allowedBinaries: ["git"],
+      worktreeRoot: "/tmp",
+      protectedPaths: [],
+      requireCwdWithinWorktree: true,
+      rejectRelativePathTraversal: true,
+      enforcePathBoundaryOnArguments: true,
+      allowedEnvAssignments: [],
+      blockedEnvAssignments: [],
+    },
+    (event) => {
+      events.push(event as unknown as Record<string, unknown>);
+    },
+  );
+
+  rules.assertToolInvocationAllowed({
+    tool: "git",
+    toolClearance: {
+      allowlist: ["git"],
+      banlist: [],
+    },
+    context: {
+      sessionId: "session-ctx",
+      nodeId: "node-ctx",
+      attempt: 2,
+    },
+  });
+
+  const allowedEvent = events.find((event) => event.type === "tool.invocation_allowed");
+  assert.ok(allowedEvent);
+  assert.equal(allowedEvent.sessionId, "session-ctx");
+  assert.equal(allowedEvent.nodeId, "node-ctx");
+  assert.equal(allowedEvent.attempt, 2);
+});
diff --git a/tests/session-lifecycle.test.ts b/tests/session-lifecycle.test.ts
index 737a8f6..7e37c9b 100644
--- a/tests/session-lifecycle.test.ts
+++ b/tests/session-lifecycle.test.ts
@@ -1,7 +1,7 @@
 import test from "node:test";
 import assert from "node:assert/strict";
 import { execFile } from "node:child_process";
-import { mkdtemp, mkdir, readFile, writeFile, stat } from "node:fs/promises";
+import { mkdtemp, mkdir, readFile, rm, stat, writeFile } from "node:fs/promises";
 import { tmpdir } from "node:os";
 import { resolve } from "node:path";
 import { promisify } from "node:util";
@@ -177,3 +177,54 @@ test("session worktree manager returns conflict outcome instead of throwing", as
   assert.equal(mergeOutcome.worktreePath, taskWorktreePath);
   assert.ok(mergeOutcome.conflictFiles.includes("README.md"));
 });
+
+test("session worktree manager recreates a task worktree after stale metadata prune", async () => {
+  const root = await mkdtemp(resolve(tmpdir(), "ai-ops-session-worktree-prune-"));
+  const projectPath = resolve(root, "project");
+  const worktreeRoot = resolve(root, "worktrees");
+
+  await mkdir(projectPath, { recursive: true });
+  await git(["init", projectPath]);
+  await git(["-C", projectPath, "config", "user.name", "AI Ops"]);
+  await git(["-C", projectPath, "config", "user.email", "ai-ops@example.local"]);
+  await writeFile(resolve(projectPath, "README.md"), "# project\n", "utf8");
+  await git(["-C", projectPath, "add", "README.md"]);
+  await git(["-C", projectPath, "commit", "-m", "initial commit"]);
+
+  const manager = new SessionWorktreeManager({
+    worktreeRoot,
+    baseRef: "HEAD",
+  });
+
+  const sessionId = "session-prune-1";
+  const taskId = "task-prune-1";
+  const baseWorkspacePath = manager.resolveBaseWorkspacePath(sessionId);
+
+  await manager.initializeSessionBaseWorkspace({
+    sessionId,
+    projectPath,
+    baseWorkspacePath,
+  });
+
+  const initialTaskWorktreePath = (
+    await manager.ensureTaskWorktree({
+      sessionId,
+      taskId,
+      baseWorkspacePath,
+    })
+  ).taskWorktreePath;
+
+  await rm(initialTaskWorktreePath, { recursive: true, force: true });
+
+  const recreatedTaskWorktreePath = (
+    await manager.ensureTaskWorktree({
+      sessionId,
+      taskId,
+      baseWorkspacePath,
+    })
+  ).taskWorktreePath;
+
+  assert.equal(recreatedTaskWorktreePath, initialTaskWorktreePath);
+  const stats = await stat(recreatedTaskWorktreePath);
+  assert.equal(stats.isDirectory(), true);
+});