Files
codex/codex-rs/core/src/state/session.rs
T
pakrym-oaiandGitHub 87ab01834a [codex] Add new context window tool (#27488)
## Why

The token budget feature tells the model how much room remains in the
current context window. When the model decides the current window is no
longer useful, it needs a way to ask Codex to start over with a fresh
context window without spending tokens on a compaction summary.

This PR adds that model-requestable escape hatch on top of #27438.

## What changed

- Added a direct-model-only `new_context` tool behind
`Feature::TokenBudget`.
- Stores the tool request on `AutoCompactWindow` and consumes it after
sampling so the next follow-up request in the same turn starts in the
new window.
- Starts the new window as a no-summary compaction checkpoint that
contains only fresh initial context, not preserved conversation history.
- Keeps the new window aligned with token-budget startup context,
including the `Current context window Z` message.
- Added integration coverage and a snapshot showing the same-turn
`new_context` flow into a fresh full-context follow-up request.

## Validation

- `just test -p codex-core token_budget`
2026-06-11 03:39:07 +00:00

312 lines
11 KiB
Rust

//! Session-wide mutable state.
use codex_protocol::models::AdditionalPermissionProfile;
use codex_protocol::models::ResponseItem;
use codex_sandboxing::policy_transforms::merge_permission_profiles;
use std::collections::HashMap;
use std::collections::HashSet;
use std::collections::VecDeque;
use super::AdditionalContextStore;
use super::auto_compact_window::AutoCompactWindow;
use super::auto_compact_window::AutoCompactWindowSnapshot;
use crate::context_manager::ContextManager;
use crate::session::PreviousTurnSettings;
use crate::session::session::SessionConfiguration;
use crate::session_startup_prewarm::SessionStartupPrewarmHandle;
use codex_protocol::protocol::RateLimitSnapshot;
use codex_protocol::protocol::TokenUsage;
use codex_protocol::protocol::TokenUsageInfo;
use codex_protocol::protocol::TurnContextItem;
use codex_utils_output_truncation::TruncationPolicy;
/// Persistent, session-scoped state previously stored directly on `Session`.
pub(crate) struct SessionState {
pub(crate) session_configuration: SessionConfiguration,
pub(crate) history: ContextManager,
pub(crate) latest_rate_limits: Option<RateLimitSnapshot>,
pub(crate) server_reasoning_included: bool,
pub(crate) mcp_dependency_prompted: HashSet<String>,
pub(crate) additional_context: AdditionalContextStore,
/// Settings used by the latest regular user turn, used for turn-to-turn
/// model/realtime handling on subsequent regular turns (including full-context
/// reinjection after resume or `/compact`).
previous_turn_settings: Option<PreviousTurnSettings>,
/// Runtime accounting state for the active auto-compaction window.
auto_compact_window: AutoCompactWindow,
/// Startup prewarmed session prepared during session initialization.
pub(crate) startup_prewarm: Option<SessionStartupPrewarmHandle>,
pub(crate) active_connector_selection: HashSet<String>,
pub(crate) pending_session_start_sources: VecDeque<codex_hooks::SessionStartSource>,
granted_permissions_by_environment_id: HashMap<String, AdditionalPermissionProfile>,
next_turn_is_first: bool,
}
impl SessionState {
/// Create a new session state mirroring previous `State::default()` semantics.
pub(crate) fn new(session_configuration: SessionConfiguration) -> Self {
let history = ContextManager::new();
Self {
session_configuration,
history,
latest_rate_limits: None,
server_reasoning_included: false,
mcp_dependency_prompted: HashSet::new(),
additional_context: AdditionalContextStore::default(),
previous_turn_settings: None,
auto_compact_window: AutoCompactWindow::new(),
startup_prewarm: None,
active_connector_selection: HashSet::new(),
pending_session_start_sources: VecDeque::new(),
granted_permissions_by_environment_id: HashMap::new(),
next_turn_is_first: true,
}
}
// History helpers
pub(crate) fn record_items<I>(&mut self, items: I, policy: TruncationPolicy)
where
I: IntoIterator,
I::Item: std::ops::Deref<Target = ResponseItem>,
{
self.history.record_items(items, policy);
}
pub(crate) fn previous_turn_settings(&self) -> Option<PreviousTurnSettings> {
self.previous_turn_settings.clone()
}
pub(crate) fn set_previous_turn_settings(
&mut self,
previous_turn_settings: Option<PreviousTurnSettings>,
) {
self.previous_turn_settings = previous_turn_settings;
}
pub(crate) fn set_next_turn_is_first(&mut self, value: bool) {
self.next_turn_is_first = value;
}
pub(crate) fn take_next_turn_is_first(&mut self) -> bool {
let is_first_turn = self.next_turn_is_first;
self.next_turn_is_first = false;
is_first_turn
}
pub(crate) fn clone_history(&self) -> ContextManager {
self.history.clone()
}
pub(crate) fn replace_history(
&mut self,
items: Vec<ResponseItem>,
reference_context_item: Option<TurnContextItem>,
) {
self.history.replace(items);
self.history
.set_reference_context_item(reference_context_item);
self.auto_compact_window.clear_prefill();
}
pub(crate) fn set_token_info(&mut self, info: Option<TokenUsageInfo>) {
self.history.set_token_info(info);
}
pub(crate) fn set_reference_context_item(&mut self, item: Option<TurnContextItem>) {
self.history.set_reference_context_item(item);
}
pub(crate) fn reference_context_item(&self) -> Option<TurnContextItem> {
self.history.reference_context_item()
}
// Token/rate limit helpers
pub(crate) fn update_token_info_from_usage(
&mut self,
usage: &TokenUsage,
model_context_window: Option<i64>,
) {
self.history.update_token_info(usage, model_context_window);
}
pub(crate) fn ensure_auto_compact_window_server_prefill_from_usage(
&mut self,
usage: &TokenUsage,
) {
self.auto_compact_window
.ensure_server_observed_prefill_from_usage(usage);
}
pub(crate) fn set_auto_compact_window_estimated_prefill(&mut self, tokens: i64) {
self.auto_compact_window.set_estimated_prefill(tokens);
}
pub(crate) fn auto_compact_window_snapshot(&self) -> AutoCompactWindowSnapshot {
self.auto_compact_window.snapshot()
}
pub(crate) fn auto_compact_window_id(&self) -> u64 {
self.auto_compact_window.window_id()
}
pub(crate) fn set_auto_compact_window_id(&mut self, window_id: u64) {
self.auto_compact_window.set_window_id(window_id);
}
pub(crate) fn advance_auto_compact_window_id(&mut self) -> u64 {
self.auto_compact_window.advance_window_id()
}
pub(crate) fn request_new_context_window(&mut self) {
self.auto_compact_window.request_new_context_window();
}
pub(crate) fn start_new_context_window_if_requested(&mut self) -> Option<u64> {
if !self.auto_compact_window.take_new_context_window_request() {
return None;
}
let window_id = self.auto_compact_window.advance_window_id();
self.auto_compact_window.clear_prefill();
Some(window_id)
}
pub(crate) fn token_info(&self) -> Option<TokenUsageInfo> {
self.history.token_info()
}
pub(crate) fn set_rate_limits(&mut self, snapshot: RateLimitSnapshot) {
self.latest_rate_limits = Some(merge_rate_limit_fields(
self.latest_rate_limits.as_ref(),
snapshot,
));
}
pub(crate) fn token_info_and_rate_limits(
&self,
) -> (Option<TokenUsageInfo>, Option<RateLimitSnapshot>) {
(self.token_info(), self.latest_rate_limits.clone())
}
pub(crate) fn set_token_usage_full(&mut self, context_window: i64) {
self.history.set_token_usage_full(context_window);
}
pub(crate) fn get_total_token_usage(&self, server_reasoning_included: bool) -> i64 {
self.history
.get_total_token_usage(server_reasoning_included)
}
pub(crate) fn set_server_reasoning_included(&mut self, included: bool) {
self.server_reasoning_included = included;
}
pub(crate) fn server_reasoning_included(&self) -> bool {
self.server_reasoning_included
}
pub(crate) fn record_mcp_dependency_prompted<I>(&mut self, names: I)
where
I: IntoIterator<Item = String>,
{
self.mcp_dependency_prompted.extend(names);
}
pub(crate) fn mcp_dependency_prompted(&self) -> HashSet<String> {
self.mcp_dependency_prompted.clone()
}
pub(crate) fn set_session_startup_prewarm(
&mut self,
startup_prewarm: SessionStartupPrewarmHandle,
) {
self.startup_prewarm = Some(startup_prewarm);
}
pub(crate) fn take_session_startup_prewarm(&mut self) -> Option<SessionStartupPrewarmHandle> {
self.startup_prewarm.take()
}
// Adds connector IDs to the active set and returns the merged selection.
pub(crate) fn merge_connector_selection<I>(&mut self, connector_ids: I) -> HashSet<String>
where
I: IntoIterator<Item = String>,
{
self.active_connector_selection.extend(connector_ids);
self.active_connector_selection.clone()
}
// Returns the current connector selection tracked on session state.
pub(crate) fn get_connector_selection(&self) -> HashSet<String> {
self.active_connector_selection.clone()
}
// Removes all currently tracked connector selections.
pub(crate) fn clear_connector_selection(&mut self) {
self.active_connector_selection.clear();
}
pub(crate) fn queue_pending_session_start_source(
&mut self,
value: codex_hooks::SessionStartSource,
) {
self.pending_session_start_sources.push_back(value);
}
pub(crate) fn take_pending_session_start_source(
&mut self,
) -> Option<codex_hooks::SessionStartSource> {
self.pending_session_start_sources.pop_front()
}
pub(crate) fn record_granted_permissions(
&mut self,
environment_id: &str,
permissions: AdditionalPermissionProfile,
) {
let granted_permissions = merge_permission_profiles(
self.granted_permissions_by_environment_id
.get(environment_id),
Some(&permissions),
);
if let Some(granted_permissions) = granted_permissions {
self.granted_permissions_by_environment_id
.insert(environment_id.to_string(), granted_permissions);
}
}
pub(crate) fn granted_permissions(
&self,
environment_id: &str,
) -> Option<AdditionalPermissionProfile> {
self.granted_permissions_by_environment_id
.get(environment_id)
.cloned()
}
}
// Sometimes new snapshots don't include credits or plan information.
// Preserve those from the previous snapshot when missing. For `limit_id`, treat
// missing values as the default `"codex"` bucket.
fn merge_rate_limit_fields(
previous: Option<&RateLimitSnapshot>,
mut snapshot: RateLimitSnapshot,
) -> RateLimitSnapshot {
if snapshot.limit_id.is_none() {
snapshot.limit_id = Some("codex".to_string());
}
if snapshot.credits.is_none() {
snapshot.credits = previous.and_then(|prior| prior.credits.clone());
}
if snapshot.individual_limit.is_none() {
snapshot.individual_limit = previous.and_then(|prior| prior.individual_limit.clone());
}
if snapshot.plan_type.is_none() {
snapshot.plan_type = previous.and_then(|prior| prior.plan_type);
}
snapshot
}
#[cfg(test)]
#[path = "session_tests.rs"]
mod tests;