diff --git a/crates/ide-agent/src/lib.rs b/crates/ide-agent/src/lib.rs
index 66786c1d..a65400a6 100644
--- a/crates/ide-agent/src/lib.rs
+++ b/crates/ide-agent/src/lib.rs
@@ -345,6 +345,14 @@ impl AgentManager {
         provider::set_builtin_command(&dir, id, command.as_deref())
     }
 
+    /// Sets the environment variables built-in `id` starts with; empty clears them.
+    pub fn set_builtin_env(&self, id: &str, env: std::collections::BTreeMap<String, String>) -> IdeResult<()> {
+        let Some(dir) = self.shared.paths.custom_agents_dir.clone() else {
+            return Err(IdeError::unavailable("there is no custom agents directory"));
+        };
+        provider::set_builtin_env(&dir, id, env)
+    }
+
     /// Re-reads configured/installed agents, drops cached probes, and notifies subscribers.
     pub fn reload_providers(&self) {
         let specs = provider::load(self.shared.paths.custom_agents_dir.as_deref());
diff --git a/crates/ide-agent/src/model.rs b/crates/ide-agent/src/model.rs
index a6a96e77..41cf2875 100644
--- a/crates/ide-agent/src/model.rs
+++ b/crates/ide-agent/src/model.rs
@@ -3,6 +3,7 @@
 use ide_core::IpcPath;
 use serde::{Deserialize, Serialize};
 use specta::Type;
+use std::collections::BTreeMap;
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]
@@ -357,6 +358,8 @@ pub struct AgentProvider {
     pub command_read_only_reason: Option<AgentCommandReadOnlyReason>,
     /// Whether the command was found (on `PATH`).
     pub installed: bool,
+    /// Environment variables it starts with (from its agent file).
+    pub env: BTreeMap<String, String>,
     /// Settings (models, modes…) the agent offered last time it ran; empty before its first session.
     pub config: Vec<AgentConfigOption>,
     /// Slash commands it offered last time.
diff --git a/crates/ide-agent/src/provider.rs b/crates/ide-agent/src/provider.rs
index 0b39eade..410bb89e 100644
--- a/crates/ide-agent/src/provider.rs
+++ b/crates/ide-agent/src/provider.rs
@@ -124,6 +124,7 @@ pub(crate) fn describe(spec: &ProviderSpec) -> AgentProvider {
         command_editable: reason.is_none(),
         command_read_only_reason: reason,
         installed: installed(&spec.command),
+        env: spec.env.iter().cloned().collect(),
         config: vec![],
         commands: vec![],
         source: spec.source.clone(),
@@ -133,6 +134,16 @@ pub(crate) fn describe(spec: &ProviderSpec) -> AgentProvider {
 /// Overrides built-in `id`'s command through its agent file, preserving other
 /// customizations. `None` restores the built-in command and removes a redundant file.
 pub(crate) fn set_builtin_command(custom_dir: &Path, id: &str, command: Option<&str>) -> IdeResult<()> {
+    update_builtin(custom_dir, id, |agent, builtin| agent.command = command.unwrap_or(&builtin.command).to_owned())
+}
+
+/// The environment built-in `id` starts with, through its agent file (empty clears it).
+pub(crate) fn set_builtin_env(custom_dir: &Path, id: &str, env: BTreeMap<String, String>) -> IdeResult<()> {
+    update_builtin(custom_dir, id, |agent, _| agent.env = env)
+}
+
+/// Changes built-in `id`'s agent file; a file left with only the built-in's values is removed.
+fn update_builtin(custom_dir: &Path, id: &str, change: impl FnOnce(&mut CustomAgent, &ProviderSpec)) -> IdeResult<()> {
     let Some(builtin) = builtin_spec(id) else {
         return Err(IdeError::invalid(format!("{id} is not a built-in agent")));
     };
@@ -152,7 +163,8 @@ pub(crate) fn set_builtin_command(custom_dir: &Path, id: &str, command: Option<&
     if agent.registry.is_some() {
         return Err(IdeError::invalid(format!("{id} is installed from the ACP Registry")));
     }
-    if command.is_none()
+    change(&mut agent, &builtin);
+    if agent.command == builtin.command
         && agent.name.as_deref() == Some(builtin.name.as_str())
         && agent.driver == builtin.driver
         && agent.args == builtin.args
@@ -164,7 +176,6 @@ pub(crate) fn set_builtin_command(custom_dir: &Path, id: &str, command: Option<&
         }
         return Ok(());
     }
-    agent.command = command.unwrap_or(&builtin.command).to_owned();
     agent.write(&file)?;
     Ok(())
 }
@@ -368,6 +379,23 @@ mod tests {
         assert!(installed("sh"));
     }
 
+    #[test]
+    fn set_builtin_env_writes_and_clears_the_environment() {
+        let dir = tempfile::tempdir().unwrap();
+        let env = BTreeMap::from([("CLAUDE_CODE_ENTRYPOINT".to_owned(), "openidea".to_owned())]);
+        set_builtin_env(dir.path(), "claude", env.clone()).unwrap();
+        let claude = load(Some(dir.path())).into_iter().find(|s| s.id == "claude").unwrap();
+        assert_eq!(claude.env, vec![("CLAUDE_CODE_ENTRYPOINT".to_owned(), "openidea".to_owned())]);
+        assert_eq!(describe(&claude).env, env);
+        // The command override and the environment are kept independently.
+        set_builtin_command(dir.path(), "claude", Some("/opt/claude")).unwrap();
+        set_builtin_command(dir.path(), "claude", None).unwrap();
+        assert!(dir.path().join("claude.toml").is_file());
+        set_builtin_env(dir.path(), "claude", BTreeMap::new()).unwrap();
+        assert!(!dir.path().join("claude.toml").exists());
+        set_builtin_env(dir.path(), "not-a-builtin", env).unwrap_err();
+    }
+
     #[test]
     fn set_builtin_command_overrides_and_clears_a_builtin() {
         let dir = tempfile::tempdir().unwrap();
diff --git a/crates/ide-host/src/ops/agent.rs b/crates/ide-host/src/ops/agent.rs
index 758cebb9..9662dc07 100644
--- a/crates/ide-host/src/ops/agent.rs
+++ b/crates/ide-host/src/ops/agent.rs
@@ -30,6 +30,17 @@ pub fn set_command(host: &Host, window: &str, id: String, command: Option<String
     host.project(window)?.agents.set_builtin_command(&id, command)
 }
 
+/// Environment variables built-in agent `id` starts with; empty clears them.
+pub fn set_env(
+    host: &Host,
+    window: &str,
+    id: String,
+    env: std::collections::BTreeMap<String, String>,
+) -> IdeResult<()> {
+    host.require_trust(window)?;
+    host.project(window)?.agents.set_builtin_env(&id, env)
+}
+
 /// Where ACP Registry agents are saved (`<config>/agents`, like the user's own) and installed.
 pub(crate) fn registry_paths(host: &Host) -> RegistryPaths {
     RegistryPaths::new(&host.config_dir, &host.local_data_dir)
@@ -195,6 +206,7 @@ pub(crate) fn register(d: &mut Dispatcher) {
     d.add("agent_subscribe", |c| async move { subscribe(&c.host, &c.window, c.channel("onEvent")?) });
     d.add("agent_providers", |c| async move { providers(&c.host, &c.window) });
     d.add("agent_set_command", |c| async move { set_command(&c.host, &c.window, c.arg("id")?, c.arg("command")?) });
+    d.add("agent_set_env", |c| async move { set_env(&c.host, &c.window, c.arg("id")?, c.arg("env")?) });
     d.add("agent_registry_list", |c| async move { registry_list(&c.host, &c.window, c.arg("request")?).await });
     d.add("agent_registry_install", |c| async move {
         registry_install(&c.host, &c.window, c.arg("id")?, c.arg("request")?, c.sender("onEvent")?).await
diff --git a/src-tauri/src/commands/agent.rs b/src-tauri/src/commands/agent.rs
index cf870663..f26c37bf 100644
--- a/src-tauri/src/commands/agent.rs
+++ b/src-tauri/src/commands/agent.rs
@@ -49,6 +49,19 @@ pub fn agent_set_command(
     agent::set_command(&state.host, window.label(), id, command)
 }
 
+/// Environment variables built-in agent `id` starts with (saved in its agent file);
+/// an empty map clears them.
+#[tauri::command]
+#[specta::specta]
+pub fn agent_set_env(
+    window: Window,
+    state: State<'_, AppState>,
+    id: String,
+    env: std::collections::BTreeMap<String, String>,
+) -> IdeResult<()> {
+    agent::set_env(&state.host, window.label(), id, env)
+}
+
 /// Agents of the ACP Registry this machine can run, with what is installed; the list
 /// saved earlier when the registry is unreachable. Cancel with `cancel_request(request)`.
 #[tauri::command]
diff --git a/src-tauri/src/commands/mod.rs b/src-tauri/src/commands/mod.rs
index c3b6a0f0..af70e0da 100644
--- a/src-tauri/src/commands/mod.rs
+++ b/src-tauri/src/commands/mod.rs
@@ -98,6 +98,7 @@ pub fn builder() -> tauri_specta::Builder<tauri::Wry> {
         agent::agent_subscribe,
         agent::agent_providers,
         agent::agent_set_command,
+        agent::agent_set_env,
         agent::agent_registry_list,
         agent::agent_registry_install,
         agent::agent_registry_remove,
diff --git a/src/bindings.ts b/src/bindings.ts
index 156b1269..3367ae16 100644
--- a/src/bindings.ts
+++ b/src/bindings.ts
@@ -91,6 +91,11 @@ export const commands = {
 	 *  built-in's driver and arguments), or returns it to auto-detection with `None`.
 	 */
 	agentSetCommand: (id: string, command: string | null) => typedError<null, IdeError>(__TAURI_INVOKE("agent_set_command", { id, command })),
+	/**
+	 *  Environment variables built-in agent `id` starts with (saved in its agent file);
+	 *  an empty map clears them.
+	 */
+	agentSetEnv: (id: string, env: { [key in string]: string }) => typedError<null, IdeError>(__TAURI_INVOKE("agent_set_env", { id, env })),
 	/**
 	 *  Agents of the ACP Registry this machine can run, with what is installed; the list
 	 *  saved earlier when the registry is unreachable. Cancel with `cancel_request(request)`.
@@ -1393,6 +1398,8 @@ export type AgentProvider = {
 	commandReadOnlyReason: AgentCommandReadOnlyReason | null,
 	/**  Whether the command was found (on `PATH`). */
 	installed: boolean,
+	/**  Environment variables it starts with (from its agent file). */
+	env: { [key in string]: string },
 	/**  Settings (models, modes…) the agent offered last time it ran; empty before its first session. */
 	config: AgentConfigOption[],
 	/**  Slash commands it offered last time. */
diff --git a/src/features/agents/BuiltinAgents.tsx b/src/features/agents/BuiltinAgents.tsx
index 760a5eb2..13a4c879 100644
--- a/src/features/agents/BuiltinAgents.tsx
+++ b/src/features/agents/BuiltinAgents.tsx
@@ -93,6 +93,14 @@ function Details({
     onChanged?.();
     return command === agent.defaultProgram ? "" : (command ?? "");
   });
+  const envBase = formatEnv(agent.env);
+  const env = form.useExternal(`agents.${agent.id}.env`, envBase, async (draft) => {
+    const parsed = parseEnv(draft);
+    await backend.setEnv(agent.id, parsed);
+    await refresh();
+    onChanged?.();
+    return formatEnv(parsed);
+  });
   const [error, setError] = useState<string | null>(null);
   // An edit can have been staged by a previous page instance. Its Apply callback
   // refreshes that instance; the mounted one follows the newly applied value too.
@@ -174,6 +182,26 @@ function Details({
           )}
         </p>
       )}
+      {agent.commandReadOnlyReason !== "registry" && agent.commandReadOnlyReason !== "customAgent" && (
+        <>
+          <label className={styles.label} htmlFor={`agent-env-${agent.id}`}>
+            <T>Environment variables</T>
+          </label>
+          <div className={styles.controls}>
+            <Input
+              id={`agent-env-${agent.id}`}
+              mono
+              value={env.value}
+              disabled={env.saving}
+              placeholder="NAME=value; OTHER=value"
+              onChange={(e) => env.set(e.target.value)}
+            />
+          </div>
+          <p className={styles.hint}>
+            <T>Passed to the agent process, replacing variables of the same name. Changes apply to new sessions.</T>
+          </p>
+        </>
+      )}
       {agent.loginHint && (
         <>
           <h4 className={styles.section}>
@@ -193,6 +221,25 @@ function Details({
   );
 }
 
+/** `NAME=value` pairs separated by `;` or new lines. */
+function parseEnv(text: string): Record<string, string> {
+  const env: Record<string, string> = {};
+  for (const raw of text.split(/[;\n]/)) {
+    const pair = raw.trim();
+    if (!pair) continue;
+    const eq = pair.indexOf("=");
+    const key = eq < 0 ? "" : pair.slice(0, eq).trim();
+    if (!/^[A-Za-z_][A-Za-z0-9_]*$/.test(key)) throw new Error(tx`Expected NAME=value: ${pair}`);
+    env[key] = pair.slice(eq + 1).trim();
+  }
+  return env;
+}
+
+const formatEnv = (env: Record<string, string>) =>
+  Object.entries(env)
+    .map(([k, v]) => `${k}=${v}`)
+    .join("; ");
+
 /** Login hints are plain text with optional backtick-delimited command spans. */
 function LoginHint({ text }: { text: string }) {
   const translate = useTx();
diff --git a/src/features/agents/agentRegistry.test.tsx b/src/features/agents/agentRegistry.test.tsx
index 98624633..76aadae1 100644
--- a/src/features/agents/agentRegistry.test.tsx
+++ b/src/features/agents/agentRegistry.test.tsx
@@ -145,6 +145,7 @@ describe("agent picker", () => {
     commandEditable: true,
     commandReadOnlyReason: null,
     installed: true,
+    env: {},
     config: [],
     commands: [],
     ...p,
@@ -312,6 +313,11 @@ class FakeCommands implements CommandsBackend {
   saved: [string, string | null][] = [];
   providers = vi.fn(async () => this.list);
   chooseExecutable = vi.fn(async () => "/chosen/agent");
+  savedEnv: [string, Record<string, string>][] = [];
+  async setEnv(id: string, env: Record<string, string>) {
+    this.savedEnv.push([id, env]);
+    this.list = this.list.map((p) => (p.id === id ? { ...p, env } : p));
+  }
   async set(id: string, command: string | null) {
     this.saved.push([id, command]);
     // What the agent list shows after the override takes effect.
@@ -341,6 +347,7 @@ const claudeProvider = (command: string): AgentProvider => ({
   commandEditable: true,
   commandReadOnlyReason: null,
   installed: true,
+  env: {},
   config: [],
   commands: [],
   source: { kind: "builtin" },
@@ -436,6 +443,23 @@ describe("Built-in executable overrides", () => {
     } else expect(screen.queryByRole("dialog")).toBeNull();
   });
 
+  it("writes the agent's environment variables on Apply and shows them again", async () => {
+    const commands = new FakeCommands();
+    commands.list = [claudeProvider("claude")];
+    await openCommands(commands);
+    const env = () => screen.getByRole("textbox", { name: "Environment variables" });
+    fireEvent.change(env(), { target: { value: "CLAUDE_CODE_ENTRYPOINT=openidea; HTTPS_PROXY=http://proxy:8080" } });
+    expect(commands.savedEnv).toEqual([]);
+    await act(async () => fireEvent.click(apply()));
+    expect(commands.savedEnv).toEqual([
+      ["claude", { CLAUDE_CODE_ENTRYPOINT: "openidea", HTTPS_PROXY: "http://proxy:8080" }],
+    ]);
+    expect(env()).toHaveValue("CLAUDE_CODE_ENTRYPOINT=openidea; HTTPS_PROXY=http://proxy:8080");
+    fireEvent.change(env(), { target: { value: "" } });
+    await act(async () => fireEvent.click(apply()));
+    expect(commands.savedEnv.at(-1)).toEqual(["claude", {}]);
+  });
+
   it("Cancel discards command edits without writing", async () => {
     const commands = new FakeCommands();
     commands.list = [
diff --git a/src/features/agents/composerCommands.test.tsx b/src/features/agents/composerCommands.test.tsx
index d4d38312..a0675ba2 100644
--- a/src/features/agents/composerCommands.test.tsx
+++ b/src/features/agents/composerCommands.test.tsx
@@ -50,6 +50,7 @@ const claude: AgentProvider = {
   commandOverridden: false,
   commandEditable: true,
   commandReadOnlyReason: null,
+  env: {},
   // Offered by the agent's last session in this project.
   commands: [command("compact", "Free up context")],
 };
diff --git a/src/features/agents/registry.ts b/src/features/agents/registry.ts
index 60cb80b8..04780dd4 100644
--- a/src/features/agents/registry.ts
+++ b/src/features/agents/registry.ts
@@ -22,6 +22,7 @@ export interface RegistryBackend {
 export interface CommandsBackend {
   providers(): Promise<AgentProvider[]>;
   set(id: string, command: string | null): Promise<void>;
+  setEnv(id: string, env: Record<string, string>): Promise<void>;
   chooseExecutable(title: string, current?: string): Promise<string | null>;
 }
 
@@ -47,6 +48,9 @@ export const tauriCommands: CommandsBackend = {
   set: async (id, command) => {
     await call(commands.agentSetCommand(id, command));
   },
+  setEnv: async (id, env) => {
+    await call(commands.agentSetEnv(id, env));
+  },
 };
 
 export const DISTRIBUTION_LABEL: Record<RegistryDistribution, string> = {
diff --git a/src/platform/locales/text/zh.json b/src/platform/locales/text/zh.json
index 9bd26e1d..08db9818 100644
--- a/src/platform/locales/text/zh.json
+++ b/src/platform/locales/text/zh.json
@@ -5910,5 +5910,7 @@
   "Shelve changes “{trim}”": "搁置更改“{trim}”",
   "Unshelve “{name}”": "取消搁置“{name}”",
   "Delete shelved changes “{name}”": "删除搁置的更改“{name}”",
-  "Rename shelved changes": "重命名搁置的更改"
+  "Rename shelved changes": "重命名搁置的更改",
+  "Passed to the agent process, replacing variables of the same name. Changes apply to new sessions.": "传给智能体进程，覆盖同名变量。对新会话生效。",
+  "Expected NAME=value: {pair}": "应为 NAME=value：{pair}"
 }