diff --git a/packages/adapter-cursor/src/index.ts b/packages/adapter-cursor/src/index.ts
index 5f85e5c..dd436fe 100644
--- a/packages/adapter-cursor/src/index.ts
+++ b/packages/adapter-cursor/src/index.ts
@@ -1,7 +1,5 @@
 import type { AgentConfig, AgentFn, WorkflowContext } from "@uncaged/nerve-core";
-import { type Result, ok } from "@uncaged/nerve-core";
-
-import { type SpawnEnv, type SpawnError, spawnSafe } from "./spawn-safe.js";
+import { type Result, type SpawnEnv, type SpawnError, ok, spawnSafe } from "@uncaged/nerve-core";
 
 export type CursorAgentMode = "plan" | "ask" | "default";
 
diff --git a/packages/adapter-cursor/src/spawn-safe.ts b/packages/adapter-cursor/src/spawn-safe.ts
deleted file mode 100644
index dd86463..0000000
--- a/packages/adapter-cursor/src/spawn-safe.ts
+++ /dev/null
@@ -1,186 +0,0 @@
-import { spawn } from "node:child_process";
-import { homedir } from "node:os";
-import { join } from "node:path";
-import { type Result, err, ok } from "@uncaged/nerve-core";
-
-/** Compatible with `process.env` for `child_process.spawn`. */
-export type SpawnEnv = Record<string, string | undefined>;
-
-export type SpawnResult = {
-  stdout: string;
-  stderr: string;
-  exitCode: number;
-  /** OS signal name (e.g. `"SIGTERM"`) when terminated by signal; otherwise `null`. */
-  signal: string | null;
-};
-
-export type SpawnError =
-  | {
-      kind: "non_zero_exit";
-      stdout: string;
-      stderr: string;
-      exitCode: number;
-      signal: string | null;
-    }
-  | { kind: "timeout"; stdout: string; stderr: string }
-  | { kind: "spawn_failed"; message: string }
-  | { kind: "aborted" };
-
-export type SpawnSafeOptions = {
-  cwd: string | null;
-  /** When null, merges {@link nerveCommandEnv} over `process.env`. When set, merges over that default. */
-  env: SpawnEnv | null;
-  timeoutMs: number | null;
-  dryRun: boolean;
-  /** When non-null, child is terminated on abort; if `timeoutMs` is also null, no internal wall-clock timer is used. */
-  abortSignal: AbortSignal | null;
-};
-
-type SpawnSafeOptionsInput = SpawnSafeOptions | Omit<SpawnSafeOptions, "dryRun">;
-
-const DEFAULT_TIMEOUT_MS = 300_000;
-
-export function nerveCommandEnv(): SpawnEnv {
-  const home = homedir();
-  const pnpmHome = join(home, ".local/share/pnpm");
-  return {
-    ...process.env,
-    PNPM_HOME: pnpmHome,
-    PATH: `${pnpmHome}:${process.env.PATH ?? ""}`,
-  };
-}
-
-function mergeEnv(user: SpawnEnv | null): SpawnEnv {
-  const base = nerveCommandEnv();
-  if (user === null) {
-    return base;
-  }
-  return { ...base, ...user };
-}
-
-function resolveWallClockMs(
-  timeoutMs: number | null,
-  abortSignal: AbortSignal | null,
-): number | null {
-  if (timeoutMs === null) {
-    if (abortSignal !== null) {
-      return null;
-    }
-    return DEFAULT_TIMEOUT_MS;
-  }
-  return timeoutMs;
-}
-
-function resolveDryRun(options: SpawnSafeOptionsInput): boolean {
-  return "dryRun" in options ? options.dryRun : false;
-}
-
-function normalizeAbortSignal(options: SpawnSafeOptionsInput): AbortSignal | null {
-  return "abortSignal" in options ? options.abortSignal : null;
-}
-
-export function spawnSafe(
-  command: string,
-  args: ReadonlyArray<string>,
-  options: SpawnSafeOptionsInput,
-): Promise<Result<SpawnResult, SpawnError>> {
-  const dryRun = resolveDryRun(options);
-  if (dryRun) {
-    return Promise.resolve(
-      ok({
-        stdout: "[dryRun] skipped",
-        stderr: "",
-        exitCode: 0,
-        signal: null,
-      }),
-    );
-  }
-
-  const abortSignal = normalizeAbortSignal(options);
-  if (abortSignal?.aborted) {
-    return Promise.resolve(err({ kind: "aborted" }));
-  }
-
-  return new Promise((resolve) => {
-    const cwd = options.cwd === null ? process.cwd() : options.cwd;
-    const env = mergeEnv(options.env);
-    const wallClockMs = resolveWallClockMs(options.timeoutMs, abortSignal);
-
-    const child = spawn(command, args, {
-      cwd,
-      env,
-      shell: false,
-      stdio: ["ignore", "pipe", "pipe"],
-    });
-
-    let stdout = "";
-    let stderr = "";
-    let settled = false;
-
-    let timer: ReturnType<typeof setTimeout> | undefined;
-    const finish = (outcome: Result<SpawnResult, SpawnError>) => {
-      if (settled) {
-        return;
-      }
-      settled = true;
-      if (timer !== undefined) {
-        clearTimeout(timer);
-      }
-      if (abortSignal !== null) {
-        abortSignal.removeEventListener("abort", onAbort);
-      }
-      resolve(outcome);
-    };
-
-    function onAbort() {
-      child.kill("SIGTERM");
-      finish(err({ kind: "aborted" }));
-    }
-
-    if (abortSignal !== null) {
-      abortSignal.addEventListener("abort", onAbort);
-    }
-
-    if (wallClockMs !== null) {
-      timer = setTimeout(() => {
-        child.kill("SIGTERM");
-        finish(err({ kind: "timeout", stdout, stderr }));
-      }, wallClockMs);
-    }
-
-    child.stdout?.on("data", (chunk: Buffer | string) => {
-      stdout += typeof chunk === "string" ? chunk : chunk.toString("utf-8");
-    });
-    child.stderr?.on("data", (chunk: Buffer | string) => {
-      stderr += typeof chunk === "string" ? chunk : chunk.toString("utf-8");
-    });
-
-    child.on("error", (cause: Error) => {
-      finish(err({ kind: "spawn_failed", message: cause.message }));
-    });
-
-    child.on("close", (code, signal) => {
-      const exitCode = code ?? 1;
-      const sig = signal === undefined || signal === null ? null : String(signal);
-      const result: SpawnResult = {
-        stdout: stdout.trimEnd(),
-        stderr: stderr.trimEnd(),
-        exitCode,
-        signal: sig,
-      };
-      if (exitCode !== 0) {
-        finish(
-          err({
-            kind: "non_zero_exit",
-            stdout: result.stdout,
-            stderr: result.stderr,
-            exitCode,
-            signal: sig,
-          }),
-        );
-        return;
-      }
-      finish(ok(result));
-    });
-  });
-}
diff --git a/packages/adapter-hermes/src/index.ts b/packages/adapter-hermes/src/index.ts
index 66c8cd8..03fa9ad 100644
--- a/packages/adapter-hermes/src/index.ts
+++ b/packages/adapter-hermes/src/index.ts
@@ -1,7 +1,5 @@
 import type { AgentConfig, AgentFn, WorkflowContext } from "@uncaged/nerve-core";
-import { type Result, ok } from "@uncaged/nerve-core";
-
-import { type SpawnEnv, type SpawnError, spawnSafe } from "./spawn-safe.js";
+import { type Result, type SpawnEnv, type SpawnError, ok, spawnSafe } from "@uncaged/nerve-core";
 
 /**
  * Spawns a non-interactive `hermes chat` invocation with YOLO enabled, argv-only
diff --git a/packages/adapter-hermes/src/spawn-safe.ts b/packages/adapter-hermes/src/spawn-safe.ts
deleted file mode 100644
index dd86463..0000000
--- a/packages/adapter-hermes/src/spawn-safe.ts
+++ /dev/null
@@ -1,186 +0,0 @@
-import { spawn } from "node:child_process";
-import { homedir } from "node:os";
-import { join } from "node:path";
-import { type Result, err, ok } from "@uncaged/nerve-core";
-
-/** Compatible with `process.env` for `child_process.spawn`. */
-export type SpawnEnv = Record<string, string | undefined>;
-
-export type SpawnResult = {
-  stdout: string;
-  stderr: string;
-  exitCode: number;
-  /** OS signal name (e.g. `"SIGTERM"`) when terminated by signal; otherwise `null`. */
-  signal: string | null;
-};
-
-export type SpawnError =
-  | {
-      kind: "non_zero_exit";
-      stdout: string;
-      stderr: string;
-      exitCode: number;
-      signal: string | null;
-    }
-  | { kind: "timeout"; stdout: string; stderr: string }
-  | { kind: "spawn_failed"; message: string }
-  | { kind: "aborted" };
-
-export type SpawnSafeOptions = {
-  cwd: string | null;
-  /** When null, merges {@link nerveCommandEnv} over `process.env`. When set, merges over that default. */
-  env: SpawnEnv | null;
-  timeoutMs: number | null;
-  dryRun: boolean;
-  /** When non-null, child is terminated on abort; if `timeoutMs` is also null, no internal wall-clock timer is used. */
-  abortSignal: AbortSignal | null;
-};
-
-type SpawnSafeOptionsInput = SpawnSafeOptions | Omit<SpawnSafeOptions, "dryRun">;
-
-const DEFAULT_TIMEOUT_MS = 300_000;
-
-export function nerveCommandEnv(): SpawnEnv {
-  const home = homedir();
-  const pnpmHome = join(home, ".local/share/pnpm");
-  return {
-    ...process.env,
-    PNPM_HOME: pnpmHome,
-    PATH: `${pnpmHome}:${process.env.PATH ?? ""}`,
-  };
-}
-
-function mergeEnv(user: SpawnEnv | null): SpawnEnv {
-  const base = nerveCommandEnv();
-  if (user === null) {
-    return base;
-  }
-  return { ...base, ...user };
-}
-
-function resolveWallClockMs(
-  timeoutMs: number | null,
-  abortSignal: AbortSignal | null,
-): number | null {
-  if (timeoutMs === null) {
-    if (abortSignal !== null) {
-      return null;
-    }
-    return DEFAULT_TIMEOUT_MS;
-  }
-  return timeoutMs;
-}
-
-function resolveDryRun(options: SpawnSafeOptionsInput): boolean {
-  return "dryRun" in options ? options.dryRun : false;
-}
-
-function normalizeAbortSignal(options: SpawnSafeOptionsInput): AbortSignal | null {
-  return "abortSignal" in options ? options.abortSignal : null;
-}
-
-export function spawnSafe(
-  command: string,
-  args: ReadonlyArray<string>,
-  options: SpawnSafeOptionsInput,
-): Promise<Result<SpawnResult, SpawnError>> {
-  const dryRun = resolveDryRun(options);
-  if (dryRun) {
-    return Promise.resolve(
-      ok({
-        stdout: "[dryRun] skipped",
-        stderr: "",
-        exitCode: 0,
-        signal: null,
-      }),
-    );
-  }
-
-  const abortSignal = normalizeAbortSignal(options);
-  if (abortSignal?.aborted) {
-    return Promise.resolve(err({ kind: "aborted" }));
-  }
-
-  return new Promise((resolve) => {
-    const cwd = options.cwd === null ? process.cwd() : options.cwd;
-    const env = mergeEnv(options.env);
-    const wallClockMs = resolveWallClockMs(options.timeoutMs, abortSignal);
-
-    const child = spawn(command, args, {
-      cwd,
-      env,
-      shell: false,
-      stdio: ["ignore", "pipe", "pipe"],
-    });
-
-    let stdout = "";
-    let stderr = "";
-    let settled = false;
-
-    let timer: ReturnType<typeof setTimeout> | undefined;
-    const finish = (outcome: Result<SpawnResult, SpawnError>) => {
-      if (settled) {
-        return;
-      }
-      settled = true;
-      if (timer !== undefined) {
-        clearTimeout(timer);
-      }
-      if (abortSignal !== null) {
-        abortSignal.removeEventListener("abort", onAbort);
-      }
-      resolve(outcome);
-    };
-
-    function onAbort() {
-      child.kill("SIGTERM");
-      finish(err({ kind: "aborted" }));
-    }
-
-    if (abortSignal !== null) {
-      abortSignal.addEventListener("abort", onAbort);
-    }
-
-    if (wallClockMs !== null) {
-      timer = setTimeout(() => {
-        child.kill("SIGTERM");
-        finish(err({ kind: "timeout", stdout, stderr }));
-      }, wallClockMs);
-    }
-
-    child.stdout?.on("data", (chunk: Buffer | string) => {
-      stdout += typeof chunk === "string" ? chunk : chunk.toString("utf-8");
-    });
-    child.stderr?.on("data", (chunk: Buffer | string) => {
-      stderr += typeof chunk === "string" ? chunk : chunk.toString("utf-8");
-    });
-
-    child.on("error", (cause: Error) => {
-      finish(err({ kind: "spawn_failed", message: cause.message }));
-    });
-
-    child.on("close", (code, signal) => {
-      const exitCode = code ?? 1;
-      const sig = signal === undefined || signal === null ? null : String(signal);
-      const result: SpawnResult = {
-        stdout: stdout.trimEnd(),
-        stderr: stderr.trimEnd(),
-        exitCode,
-        signal: sig,
-      };
-      if (exitCode !== 0) {
-        finish(
-          err({
-            kind: "non_zero_exit",
-            stdout: result.stdout,
-            stderr: result.stderr,
-            exitCode,
-            signal: sig,
-          }),
-        );
-        return;
-      }
-      finish(ok(result));
-    });
-  });
-}
diff --git a/packages/workflow-utils/src/__tests__/spawn-safe.test.ts b/packages/core/src/__tests__/spawn-safe.test.ts
similarity index 96%
rename from packages/workflow-utils/src/__tests__/spawn-safe.test.ts
rename to packages/core/src/__tests__/spawn-safe.test.ts
index 9a6313d..bca7ae3 100644
--- a/packages/workflow-utils/src/__tests__/spawn-safe.test.ts
+++ b/packages/core/src/__tests__/spawn-safe.test.ts
@@ -1,6 +1,6 @@
 import { describe, expect, it } from "vitest";
 
-import { spawnSafe } from "../shared/spawn-safe.js";
+import { spawnSafe } from "../spawn-safe.js";
 
 describe("spawnSafe", () => {
   it("passes argv literally without shell interpretation (injection-safe)", async () => {
diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index 1fbad12..7145aa9 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -33,6 +33,14 @@ export type { Schema, ExtractFn } from "./extract-layer.js";
 export { ExtractError } from "./extract-layer.js";
 export type { Result } from "./result.js";
 export { ok, err } from "./result.js";
+export {
+  nerveCommandEnv,
+  spawnSafe,
+  type SpawnEnv,
+  type SpawnError,
+  type SpawnResult,
+  type SpawnSafeOptions,
+} from "./spawn-safe.js";
 export { parseNerveConfig } from "./parse-nerve-config.js";
 export type { KnowledgeConfig } from "./knowledge-config.js";
 export { parseKnowledgeYaml } from "./knowledge-config.js";
diff --git a/packages/workflow-utils/src/shared/spawn-safe.ts b/packages/core/src/spawn-safe.ts
similarity index 98%
rename from packages/workflow-utils/src/shared/spawn-safe.ts
rename to packages/core/src/spawn-safe.ts
index 3451ad1..d2c17ce 100644
--- a/packages/workflow-utils/src/shared/spawn-safe.ts
+++ b/packages/core/src/spawn-safe.ts
@@ -1,7 +1,7 @@
 import { spawn } from "node:child_process";
 import { homedir } from "node:os";
 import { join } from "node:path";
-import { type Result, err, ok } from "@uncaged/nerve-core";
+import { type Result, err, ok } from "./result.js";
 
 /** Compatible with `process.env` for `child_process.spawn`. */
 export type SpawnEnv = Record<string, string | undefined>;
diff --git a/packages/workflow-utils/src/index.ts b/packages/workflow-utils/src/index.ts
index 478da45..6df3169 100644
--- a/packages/workflow-utils/src/index.ts
+++ b/packages/workflow-utils/src/index.ts
@@ -25,7 +25,7 @@ export {
   type SpawnError,
   type SpawnResult,
   type SpawnSafeOptions,
-} from "./shared/spawn-safe.js";
+} from "@uncaged/nerve-core";
 export type { LlmError, LlmProvider } from "./shared/llm-extract.js";
 export type {
   CliPromptFn,
diff --git a/packages/workflow-utils/src/role-cursor.ts b/packages/workflow-utils/src/role-cursor.ts
index 9bee572..a827260 100644
--- a/packages/workflow-utils/src/role-cursor.ts
+++ b/packages/workflow-utils/src/role-cursor.ts
@@ -1,11 +1,10 @@
 import { type CursorAgentMode, cursorAgent } from "@uncaged/nerve-adapter-cursor";
-import type { Role } from "@uncaged/nerve-core";
+import type { Role, SpawnEnv } from "@uncaged/nerve-core";
 
 import type { CursorRoleDefaults, CursorRoleRequired } from "./role-types.js";
 import { isDryRun } from "./role-types.js";
 import { formatLlmError } from "./shared/format-error.js";
 import { llmExtract } from "./shared/llm-extract.js";
-import type { SpawnEnv } from "./shared/spawn-safe.js";
 
 const CURSOR_DEFAULTS: CursorRoleDefaults = {
   mode: "default",
diff --git a/packages/workflow-utils/src/role-types.ts b/packages/workflow-utils/src/role-types.ts
index 6e97f0b..63503f9 100644
--- a/packages/workflow-utils/src/role-types.ts
+++ b/packages/workflow-utils/src/role-types.ts
@@ -1,8 +1,7 @@
-import type { StartStep } from "@uncaged/nerve-core";
+import type { SpawnEnv, StartStep } from "@uncaged/nerve-core";
 import type { z } from "zod";
 
 import type { LlmProvider } from "./shared/llm-extract.js";
-import type { SpawnEnv } from "./shared/spawn-safe.js";
 
 /** Returns the thread-level dry-run flag from the workflow start frame. */
 export function isDryRun(start: StartStep): boolean {