diff --git a/README.md b/README.md
index 8714c2b..2d69645 100644
--- a/README.md
+++ b/README.md
@@ -458,7 +458,7 @@ cstack inspect
 cstack inspect <run-id> --interactive
 ```
 
-By default, `cstack` uses `danger-full-access` and allows direct source execution for `build`, `ship`, and `deliver`. Use `--safe` on a run when you want that invocation to fall back to `workspace-write` plus clean-worktree execution for defaulted dirty-worktree settings.
+By default, `cstack` uses `workspace-write` and isolated execution checkouts for `build`, `ship`, and `deliver`. Use `--allow-dirty` when you explicitly want direct source execution for a run.
 
 While a run is active in a normal terminal, `cstack` renders a bounded ANSI dashboard instead of endlessly appending log lines.
 
@@ -551,8 +551,8 @@ Notes:
 
 - `command` can point at the installed `codex` binary or a script path for testing.
 - `sandbox`, `profile`, `model`, and `extraArgs` are passed through to Codex launches.
-- By default, `sandbox` resolves to `danger-full-access`, and `workflows.build.allowDirty`, `workflows.ship.allowDirty`, and `workflows.deliver.allowDirty` resolve to `true`.
-- Use `--safe` when you want one run to fall back to `workspace-write` and clean-worktree execution for defaulted `allowDirty` values.
+- By default, `sandbox` resolves to `workspace-write`, and `workflows.build.allowDirty`, `workflows.ship.allowDirty`, and `workflows.deliver.allowDirty` resolve to `false`.
+- Use `--allow-dirty` when you want one run to execute directly in the source checkout.
 - If repo or user config explicitly sets `sandbox` or `allowDirty`, that explicit config wins over `--safe`.
 - `--allow-all` is deprecated and currently accepted as a temporary no-op.
 - `workflows.build.mode` selects `interactive` or `exec`; interactive is the default for build runs.
diff --git a/src/commands/build.ts b/src/commands/build.ts
index e861ef0..7a86a3d 100644
--- a/src/commands/build.ts
+++ b/src/commands/build.ts
@@ -259,7 +259,7 @@ export async function runBuild(cwd: string, args: string[] = []): Promise<string
         `Mode: requested=${requestedMode} observed=${execution.observedMode}`,
         `Status: ${runRecord.status}`,
         execution.result.sessionId ? `Session: ${execution.result.sessionId}` : "Session: not observed",
-        `Execution policy: ${policy.safe ? "dangerous default disabled via --safe" : "default dangerous execution"}`,
+        `Execution policy: ${policy.safe ? "safe overrides applied via --safe" : "default execution policy"}`,
         `Execution checkout: ${executionCheckout.record.execution.kind} @ ${executionCheckout.record.execution.cwd}`,
         `Source snapshot: ${executionCheckout.record.source.branch} ${executionCheckout.record.source.commit}`,
         executionCheckout.record.source.dirtyFiles.length > 0 && !allowDirty
diff --git a/src/commands/deliver.ts b/src/commands/deliver.ts
index f8e0525..91d32a9 100644
--- a/src/commands/deliver.ts
+++ b/src/commands/deliver.ts
@@ -300,7 +300,7 @@ export async function runDeliver(cwd: string, args: string[] = [], hooks: Delive
         `Mode: requested=${requestedMode} observed=${execution.buildExecution.observedMode}`,
         `Status: ${finalRunRecord.status}`,
         buildSession.sessionId ? `Build session: ${buildSession.sessionId}` : "Build session: not observed",
-        `Execution policy: ${policy.safe ? "dangerous default disabled via --safe" : "default dangerous execution"}`,
+        `Execution policy: ${policy.safe ? "safe overrides applied via --safe" : "default execution policy"}`,
         `Execution checkout: ${executionCheckout.record.execution.kind} @ ${executionCheckout.record.execution.cwd}`,
         `Source snapshot: ${executionCheckout.record.source.branch} ${executionCheckout.record.source.commit}`,
         executionCheckout.record.source.dirtyFiles.length > 0 && !allowDirty
diff --git a/src/commands/ship.ts b/src/commands/ship.ts
index 2ca9e33..d6f7dcd 100644
--- a/src/commands/ship.ts
+++ b/src/commands/ship.ts
@@ -252,7 +252,7 @@ export async function runShip(cwd: string, args: string[] = [], hooks: ShipRunHo
         `Run: ${runId}`,
         "Workflow: ship",
         `Status: ${finalRunRecord.status}`,
-        `Execution policy: ${policy.safe ? "dangerous default disabled via --safe" : "default dangerous execution"}`,
+        `Execution policy: ${policy.safe ? "safe overrides applied via --safe" : "default execution policy"}`,
         `Ship readiness: ${execution.shipRecord.readiness}`,
         `GitHub mutation: ${execution.githubMutationRecord.summary}`,
         `GitHub delivery: ${execution.githubDeliveryRecord.overall.status}`,
diff --git a/src/config.ts b/src/config.ts
index 3a23288..61186a9 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -7,7 +7,7 @@ import type { ConfigProvenance, ConfigValueSource, CstackConfig } from "./types.
 const DEFAULT_CONFIG: CstackConfig = {
   codex: {
     command: process.env.CSTACK_CODEX_BIN || "codex",
-    sandbox: "danger-full-access",
+    sandbox: "workspace-write",
     extraArgs: []
   },
   workflows: {
@@ -40,7 +40,7 @@ const DEFAULT_CONFIG: CstackConfig = {
     build: {
       mode: "interactive",
       verificationCommands: [],
-      allowDirty: true,
+      allowDirty: false,
       maxCodexAttempts: 3,
       timeoutSeconds: 900,
       capabilities: {
@@ -69,7 +69,7 @@ const DEFAULT_CONFIG: CstackConfig = {
     ship: {
       mode: "exec",
       verificationCommands: [],
-      allowDirty: true,
+      allowDirty: false,
       timeoutSeconds: 600,
       capabilities: {
         allowed: ["shell", "github"],
@@ -83,7 +83,7 @@ const DEFAULT_CONFIG: CstackConfig = {
     deliver: {
       mode: "interactive",
       verificationCommands: [],
-      allowDirty: true,
+      allowDirty: false,
       timeoutSeconds: 900,
       capabilities: {
         allowed: ["shell", "github", "browser"],
diff --git a/src/inspector.ts b/src/inspector.ts
index 2f860cd..d6353d5 100644
--- a/src/inspector.ts
+++ b/src/inspector.ts
@@ -1221,7 +1221,7 @@ export function renderInspectionSummary(cwd: string, inspection: RunInspection):
         ? `- source snapshot: ${inspection.executionContext.source.branch} ${inspection.executionContext.source.commit}`
         : undefined,
       inspection.executionContext
-        ? `- execution policy: ${run.inputs.safe ? "dangerous default disabled via --safe" : "default dangerous execution"}`
+        ? `- execution policy: ${run.inputs.safe ? "safe overrides applied via --safe" : "default execution policy"}`
         : undefined,
       inspection.executionContext?.source.localChangesIgnored
         ? "- local dirty changes: ignored by default; execution used committed HEAD"
diff --git a/src/runtime-config.ts b/src/runtime-config.ts
index bc7af03..96c9b33 100644
--- a/src/runtime-config.ts
+++ b/src/runtime-config.ts
@@ -58,11 +58,11 @@ export function resolveSourceExecutionReason(options: {
   if (options.configuredAllowDirtySource && options.configuredAllowDirtySource !== "default") {
     return `Direct source execution was enabled by configured allowDirty for ${options.workflow}.`;
   }
-  return `Direct source execution used the default dangerous execution policy for ${options.workflow}.`;
+  return `Direct source execution used the default execution policy for ${options.workflow}.`;
 }
 
 export function emitDeprecatedAllowAllWarning(command: string): void {
   process.stderr.write(
-    `[cstack] Warning: \`--allow-all\` is deprecated for \`${command}\` and has no effect because dangerous execution is now the default.\n`
+    `[cstack] Warning: \`--allow-all\` is deprecated for \`${command}\` and has no effect.\n`
   );
 }
diff --git a/test/build.test.ts b/test/build.test.ts
index cb11b36..52e5969 100644
--- a/test/build.test.ts
+++ b/test/build.test.ts
@@ -292,7 +292,7 @@ describe("runBuild", () => {
     expect(await fs.readFile(path.join(executionContext.execution.cwd, "codex-generated-change.txt"), "utf8")).toContain("generated");
   }, 60_000);
 
-  it("uses the source checkout and danger-full-access by default when sandbox and allowDirty are not configured", async () => {
+  it("uses an isolated checkout and workspace-write by default when sandbox and allowDirty are not configured", async () => {
     await fs.writeFile(path.join(repoDir, "local-only.txt"), "uncommitted\n", "utf8");
     const configPath = path.join(repoDir, ".cstack", "config.toml");
     await fs.writeFile(
@@ -322,15 +322,14 @@ describe("runBuild", () => {
       codexCommand: string[];
     };
 
-    expect(run.inputs.allowDirty).toBe(true);
+    expect(run.inputs.allowDirty).toBe(false);
     expect(executionContext.source.dirtyFiles).toContain("local-only.txt");
-    expect(executionContext.source.localChangesIgnored).toBe(false);
-    expect(executionContext.execution.kind).toBe("source");
-    expect(executionContext.execution.cwd).toBe(repoDir);
-    expect(executionContext.execution.notes.join(" ")).toContain("default dangerous execution policy");
+    expect(executionContext.source.localChangesIgnored).toBe(true);
+    expect(executionContext.execution.kind).toBe("git-worktree");
+    expect(executionContext.execution.cwd).not.toBe(repoDir);
     expect(session.codexCommand).toContain("--sandbox");
-    expect(session.codexCommand).toContain("danger-full-access");
-    expect(await fs.readFile(path.join(repoDir, "codex-generated-change.txt"), "utf8")).toContain("generated");
+    expect(session.codexCommand).toContain("workspace-write");
+    await expect(fs.access(path.join(repoDir, "codex-generated-change.txt"))).rejects.toThrow();
   }, 60_000);
 
   it("treats --allow-all as a deprecated no-op", async () => {
diff --git a/test/config.test.ts b/test/config.test.ts
index a51406e..a0c27b1 100644
--- a/test/config.test.ts
+++ b/test/config.test.ts
@@ -166,18 +166,18 @@ blockSeverities = ["medium", "high", "critical"]
     const { config, sources, provenance } = await loadConfig(repoDir);
 
     expect(sources).toHaveLength(0);
-    expect(config.codex.sandbox).toBe("danger-full-access");
+    expect(config.codex.sandbox).toBe("workspace-write");
     expect(config.workflows.spec.timeoutSeconds).toBe(600);
     expect(config.workflows.discover.timeoutSeconds).toBe(600);
-    expect(config.workflows.build.allowDirty).toBe(true);
+    expect(config.workflows.build.allowDirty).toBe(false);
     expect(config.workflows.build.timeoutSeconds).toBe(900);
     expect(config.workflows.review.mode).toBe("exec");
     expect(config.workflows.review.allowDirty).toBe(true);
     expect(config.workflows.review.timeoutSeconds).toBe(600);
     expect(config.workflows.ship.mode).toBe("exec");
-    expect(config.workflows.ship.allowDirty).toBe(true);
+    expect(config.workflows.ship.allowDirty).toBe(false);
     expect(config.workflows.ship.timeoutSeconds).toBe(600);
-    expect(config.workflows.deliver.allowDirty).toBe(true);
+    expect(config.workflows.deliver.allowDirty).toBe(false);
     expect(config.workflows.deliver.timeoutSeconds).toBe(900);
     expect(config.workflows.deliver.stageTimeoutSeconds?.build).toBe(900);
     expect(config.workflows.deliver.stageTimeoutSeconds?.validation).toBe(600);
diff --git a/test/deliver.test.ts b/test/deliver.test.ts
index 22b4c23..053d7ea 100644
--- a/test/deliver.test.ts
+++ b/test/deliver.test.ts
@@ -406,7 +406,7 @@ describe("runDeliver", () => {
     expect(lineage.stages.find((stage) => stage.name === "validation")?.status).toBe("deferred");
   }, 60_000);
 
-  it("uses the source checkout and danger-full-access by default when sandbox and allowDirty are not configured", async () => {
+  it("uses an isolated checkout and workspace-write by default when sandbox and allowDirty are not configured", async () => {
     const configPath = path.join(repoDir, ".cstack", "config.toml");
     const configBody = await fs.readFile(configPath, "utf8");
     await fs.writeFile(
@@ -451,15 +451,14 @@ describe("runDeliver", () => {
       codexCommand: string[];
     };
 
-    expect(run.inputs.allowDirty).toBe(true);
+    expect(run.inputs.allowDirty).toBe(false);
     expect(executionContext.source.dirtyFiles).toContain("src-change.txt");
-    expect(executionContext.source.localChangesIgnored).toBe(false);
-    expect(executionContext.execution.kind).toBe("source");
-    expect(executionContext.execution.cwd).toBe(repoDir);
-    expect(executionContext.execution.notes.join(" ")).toContain("default dangerous execution policy");
+    expect(executionContext.source.localChangesIgnored).toBe(true);
+    expect(executionContext.execution.kind).toBe("git-worktree");
+    expect(executionContext.execution.cwd).not.toBe(repoDir);
     expect(buildSession.codexCommand).toContain("--sandbox");
-    expect(buildSession.codexCommand).toContain("danger-full-access");
-    expect(await fs.readFile(path.join(repoDir, "codex-generated-change.txt"), "utf8")).toContain("generated");
+    expect(buildSession.codexCommand).toContain("workspace-write");
+    await expect(fs.access(path.join(repoDir, "codex-generated-change.txt"))).rejects.toThrow();
   }, 60_000);
 
   it("treats --allow-all as a deprecated no-op when source execution is otherwise disabled", async () => {