feat(#1969): ship claude settings via /etc/claude-code/managed-settings.json

docs/turn-loop.md

@@ -135,13 +135,22 @@ if a new inbox message arrives before this turn ends"). The
 
 ```
 claude --print --verbose --output-format stream-json --model <name> \
-  --continue --settings /run/hive/claude-settings.json \
+  --effort <level> --continue \
   --system-prompt-file /run/hive/claude-system-prompt.md \
   --mcp-config /run/hive/claude-mcp-config.json --strict-mcp-config \
   --tools <builtins> --allowedTools <builtins+mcp>
 # wake prompt piped over stdin
 ```
 
+Static settings are no longer passed with `--settings`: hive-enforced
+settings ship at `/etc/claude-code/managed-settings.json` (claude-code's
+canonical managed-settings path — precedence #1, read-only,
+un-overridable), wired in `nix/templates/harness-base.nix` from the
+`prompts/claude-settings.json` asset. `effortLevel` is deliberately not
+in that file — effort is controlled live via the `--effort` flag
+(`HIVE_DEFAULT_EFFORT` / the per-agent UI slider), which managed scope
+would otherwise lock.
+
 `<name>` is read from `Bus::model()` on each turn. The initial
 default is set by `hyperhive.model` in the agent's `agent.nix`
 (NixOS option; propagates via `HIVE_DEFAULT_MODEL` env var; falls
@@ -172,9 +181,9 @@ percentage-of-window ctx badge.
 
 `--continue` keeps a persistent session per agent (claude stores
 sessions in `~/.claude/projects/`, which is bind-mounted
-persistently). Auto-compact and auto-memory are disabled via
-`--settings` because hyperhive owns compaction — see
-[Compaction](#compaction) below.
+persistently). Auto-compact and auto-memory are disabled via the
+managed settings at `/etc/claude-code/managed-settings.json` because
+hyperhive owns compaction — see [Compaction](#compaction) below.
 A one-shot `--continue` suppression is available via
 `POST /api/new-session` (or `/new-session` slash command in the
 per-agent terminal) — `Bus::take_skip_continue()` flips an
@@ -183,8 +192,9 @@ per-agent terminal) — `Bus::take_skip_continue()` flips an
 
 ### Compaction
 
-claude's own in-session auto-compact is off (`--settings`); hyperhive
-owns it explicitly in `turn::drive_turn`. There are two triggers:
+claude's own in-session auto-compact is off (via the managed settings
+at `/etc/claude-code/managed-settings.json`); hyperhive owns it
+explicitly in `turn::drive_turn`. There are two triggers:
 
 - **Reactive** — claude-code prints `Prompt is too long` (the
   `PROMPT_TOO_LONG_MARKER`). The session is *already* past the context
@@ -255,14 +265,12 @@ next turn picks it up like any other inbox message.
 
 ### On-boot files
 
-`hive_ag3nt::turn::write_*` writes three files next to the per-agent
+`hive_ag3nt::turn::write_*` writes two files next to the per-agent
 socket at `/run/hive/` once at startup:
 
 - `claude-mcp-config.json` — re-invokes the running binary as `mcp`
   child (so the same binary serves as harness + as claude's MCP
   child process).
-- `claude-settings.json` — the `--settings` blob (auto-compact and
-  auto-memory off, effortLevel medium).
 - `claude-system-prompt.md` — rendered from
   `hive-ag3nt/prompts/system.md` by `hive_ag3nt::prompt::render`:
   HTML-comment markers (`<!-- role:agent -->...<!-- /role:agent -->`,
@@ -620,8 +628,9 @@ status hint moved to the wake prompt + UI header.
 - Allowed built-ins: `Edit`, `Glob`, `Grep`, `Read`, `Write`.
 - Tool-group-gated built-ins: `WebFetch`, `WebSearch` (added when the
   `web_tools` tool group is enabled — see P3RM1SS10NS tab).
-- Denied by omission or `claude-settings.json` deny list: `Bash`,
-  `Task`, `NotebookEdit`, `TodoWrite`.
+- Denied by omission or the managed-settings deny list
+  (`/etc/claude-code/managed-settings.json`): `Bash`, `Task`,
+  `NotebookEdit`, `TodoWrite`.
 - Allowed MCP tools: as listed above (by tool group).
 
 `Bash` is disallowed — shell execution goes through

hive-ag3nt/prompts/claude-settings.json

@@ -1,7 +1,6 @@
 {
   "autoCompactEnabled": false,
   "autoMemoryEnabled": false,
-  "effortLevel": "medium",
   "permissions": {
     "deny": ["Bash", "Task", "TodoWrite"]
   }

hive-ag3nt/src/turn.rs

@@ -9,7 +9,7 @@ use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Mutex};
 use std::time::Duration;
 
-use anyhow::{Context, Result, bail};
+use anyhow::{Result, bail};
 use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader};
 use tokio::process::Command;
 
@@ -17,12 +17,13 @@ use crate::events::{Bus, LiveEvent};
 use crate::login::LoginState;
 use crate::mcp;
 
-// `--settings` JSON is read at runtime from
-// `$HIVE_ASSETS_DIR/prompts/claude-settings.json` via
-// `hive_sh4re::assets::claude_settings()`. We turn off claude's
-// in-session auto-compaction and its cross-session auto-memory because
-// hyperhive owns those concerns (`/compact` on overflow, notes
-// persistence under `/state`). Unknown keys are silently ignored by
+// Hive-enforced claude settings ship at `/etc/claude-code/managed-settings.json`
+// (wired in `nix/templates/harness-base.nix` from the `prompts/claude-settings.json`
+// asset). claude-code auto-discovers that managed path — precedence #1,
+// read-only, un-overridable — so the harness no longer passes `--settings`.
+// We turn off claude's in-session auto-compaction and its cross-session
+// auto-memory because hyperhive owns those concerns (`/compact` on overflow,
+// notes persistence under `/state`). Unknown keys are silently ignored by
 // claude-code; if a key gets renamed we'll spot it because the
 // corresponding behavior will start firing mid-turn again.
 
@@ -95,8 +96,10 @@ conversation to go on. Do not start new work or reply to anyone — just write y
 and end the turn.";
 
 /// The set of files claude reads on every invocation: the MCP server
-/// config (`--mcp-config`), static settings (`--settings`), and the
-/// pre-rendered role/tools system prompt (`--system-prompt-file`).
+/// config (`--mcp-config`) and the pre-rendered role/tools system
+/// prompt (`--system-prompt-file`). Static settings are no longer
+/// passed here — they live at `/etc/claude-code/managed-settings.json`
+/// and claude auto-discovers them.
 /// Materialised once at harness startup; shared between the turn loop
 /// and the operator-driven `/compact` path so both invocations look
 /// identical to claude (same MCP surface, same allowed tools, same
@@ -104,7 +107,6 @@ and end the turn.";
 #[derive(Clone)]
 pub struct TurnFiles {
     pub mcp_config: PathBuf,
-    pub settings: PathBuf,
     pub system_prompt: PathBuf,
 }
 
@@ -118,7 +120,6 @@ impl TurnFiles {
     pub async fn prepare(socket: &Path, label: &str) -> Result<Self> {
         Ok(Self {
             mcp_config: write_mcp_config(socket).await?,
-            settings: write_settings(socket).await?,
             system_prompt: write_system_prompt(socket, label).await?,
         })
     }
@@ -145,33 +146,6 @@ pub async fn write_mcp_config(socket: &Path) -> Result<PathBuf> {
     Ok(path)
 }
 
-/// Drop the static `--settings` JSON next to the MCP config so we can
-/// pass a path (`--settings <file>`) instead of an ever-growing inline
-/// blob — the CLI argv has a finite length budget.
-///
-/// # Errors
-///
-/// Returns an error if the settings file cannot be written.
-pub async fn write_settings(_socket: &Path) -> Result<PathBuf> {
-    let parent = crate::paths::config_dir();
-    tokio::fs::create_dir_all(&parent).await.ok();
-    let path = parent.join("claude-settings.json");
-    // Source-of-truth is `$HIVE_ASSETS_DIR/prompts/claude-settings.json`;
-    // copy through the per-agent runtime dir so claude reads it from the
-    // same socket-adjacent location every time and so a future override
-    // (per-agent settings JSON layer) drops in cleanly.
-    let src = hive_sh4re::assets::claude_settings();
-    tokio::fs::copy(&src, &path).await.with_context(|| {
-        format!(
-            "copy claude settings from {} to {}",
-            src.display(),
-            path.display()
-        )
-    })?;
-    tracing::info!(path = %path.display(), "wrote claude settings");
-    Ok(path)
-}
-
 /// Thin re-export of [`crate::prompt::write_system_prompt`] for
 /// callers that already import this module. The actual rendering +
 /// marker-block logic lives in `prompt.rs`; this is just the public
@@ -579,8 +553,9 @@ fn session_refreshed(prev: DirSnapshot, now: DirSnapshot) -> bool {
 /// live event bus. Prompt goes over stdin (variadic
 /// `--allowedTools`/`--tools` would otherwise eat a trailing positional
 /// prompt). The session is persistent across turns via `--continue` and
-/// claude's in-session auto-compact is disabled via `--settings` so it
-/// doesn't stall mid-turn — hyperhive owns compaction.
+/// claude's in-session auto-compact is disabled via the managed
+/// settings at `/etc/claude-code/managed-settings.json` so it doesn't
+/// stall mid-turn — hyperhive owns compaction.
 pub async fn run_turn(prompt: &str, files: &TurnFiles, bus: &Bus) -> TurnOutcome {
     match run_claude(prompt, files, bus).await {
         Ok((true, _, _)) => TurnOutcome::PromptTooLong,
@@ -675,9 +650,7 @@ async fn run_claude(prompt: &str, files: &TurnFiles, bus: &Bus) -> Result<(bool,
         .arg("--model")
         .arg(&model)
         .arg("--effort")
-        .arg(&effort)
-        .arg("--settings")
-        .arg(&files.settings);
+        .arg(&effort);
     if resume {
         cmd.arg("--continue");
     }

hive-ag3nt/src/web_ui.rs

@@ -51,9 +51,9 @@ struct AppState {
     bus: Bus,
     socket: PathBuf,
     /// Same `TurnFiles` the harness's turn loop uses. Shared so
-    /// `/api/compact` re-uses the exact MCP config / system prompt /
-    /// settings claude saw on the last regular turn — keeps the
-    /// session shape identical across compact + normal turns.
+    /// `/api/compact` re-uses the exact MCP config / system prompt
+    /// claude saw on the last regular turn — keeps the session shape
+    /// identical across compact + normal turns.
     files: TurnFiles,
     /// Prevents `/api/compact` from racing with an in-flight normal turn.
     turn_lock: TurnLock,

hive-sh4re/src/assets.rs

@@ -90,10 +90,3 @@ pub fn config_org_avatar_png() -> PathBuf {
 pub fn prompt_template() -> PathBuf {
     dir().join("prompts/system.md")
 }
-
-/// `$HIVE_ASSETS_DIR/prompts/claude-settings.json` — the static
-/// `--settings` JSON every claude invocation reads.
-#[must_use]
-pub fn claude_settings() -> PathBuf {
-    dir().join("prompts/claude-settings.json")
-}

nix/templates/harness-base.nix

@@ -1066,6 +1066,16 @@ in
     environment.etc."hyperhive/claude-plugins-auto-update.json".text =
       builtins.toJSON config.hyperhive.claudePluginsAutoUpdate;
 
+    # Hive-enforced claude settings. claude-code auto-discovers managed
+    # settings at this canonical Linux path (precedence #1, read-only,
+    # un-overridable by user/project/CLI) — so the harness no longer
+    # passes `--settings` or copies the blob per turn. effortLevel is
+    # deliberately NOT shipped here: effort is controlled live via the
+    # `--effort` CLI flag (HIVE_DEFAULT_EFFORT / the per-agent UI slider),
+    # which managed scope would otherwise override and lock.
+    environment.etc."claude-code/managed-settings.json".source =
+      "${pkgs.hyperhive-assets}/share/hyperhive/prompts/claude-settings.json";
+
     # Merged frontend static tree. Base = `${frontend.dist}/agent/`,
     # then each `extraFiles` entry is laid on top at its `target`
     # path. The runCommand derivation aborts on overwrite so a