## Stack
1. Parent PR: #18868 adds MITM hook config and model only.
2. This PR wires runtime enforcement.
3. User facing config follow up: #18240 moves MITM policy into the
PermissionProfile network tree.
## Why
1. After the hook model exists, the proxy needs a separate behavior
change that can be tested at the request path.
2. This PR makes hooked HTTPS hosts require MITM, evaluates inner
requests after CONNECT, mutates headers for matching hooks, and blocks
hooked hosts when no hook matches.
3. It also fixes the activation path so a permission profile with MITM
hook policy starts the managed proxy.
4. Keeping this separate from #18868 lets reviewers focus on runtime
effects, telemetry, and request mutation.
## Summary
1. Store compiled MITM hooks in network proxy state.
2. Require MITM for hooked hosts even when network mode is full.
3. Evaluate inner HTTPS requests against host specific hooks.
4. Apply hook actions by replacing request headers before forwarding.
5. Block hooked hosts when no hook matches and record block telemetry.
6. Treat profile MITM hook policy as managed proxy policy so the proxy
starts when needed.
7. Keep the duplicate authorization header replacement and query
preserving request rebuild in this runtime PR.
8. Add runtime tests and README guidance for hook enforcement.
## Validation
1. Ran the network proxy MITM policy tests.
2. Ran the hooked host CONNECT test.
3. Ran the authorization header replacement test.
4. Ran the core permission profile proxy activation test for MITM hooks.
5. Ran the scoped Clippy fixer for the network proxy crate.
6. Ran the scoped Clippy fixer for the core crate.
## Stack
1. This PR adds MITM hook config and model only.
2. Runtime follow up: #20659 wires hook enforcement into the proxy
request path.
3. User facing config follow up: #18240 moves MITM policy into the
PermissionProfile network tree.
## Why
1. Viyat asked for the original parent PR to be split so reviewers can
inspect the policy model before request behavior changes.
2. This PR gives the proxy a typed MITM hook model, validation, matcher
compilation, permissions TOML plumbing, schema support, and config
tests.
3. This PR deliberately does not change CONNECT or MITM request
handling.
4. Keeping runtime behavior out of this PR makes the review boundary
simple: does the policy model parse, validate, compile, and lower
correctly.
## Summary
1. Add the MITM hook config model and matcher compilation.
2. Validate hosts, methods, paths, query matchers, header matchers,
secret sources, and reserved body matching.
3. Add wildcard matcher support for path, query value, and header value
matching.
4. Add permissions TOML and schema support for flat runtime hook config.
5. Add config loader tests for MITM hook overlay behavior.
## Validation
1. Regenerated the config schema.
2. Ran the network proxy MITM hook unit tests.
3. Ran the core permission profile MITM hook parsing tests.
4. Ran the core config schema fixture test.
5. Ran the scoped Clippy fixer for the network proxy crate.
6. Ran the scoped Clippy fixer for the core crate.
## Notes
1. Runtime enforcement moved to #20659.
2. User facing PermissionProfile TOML shape remains in #18240.
## Why
The proxy checks the requested host before opening the upstream
connection, but DNS can resolve an allowed hostname to a loopback,
private, or other non-public address after that first decision. Without
a final check on the actual socket target, a request that looks
acceptable at the hostname layer can still connect to a local service
once resolution completes.
## What changed
- add a shared TCP connector check for direct proxy egress
- use that path for HTTP, `CONNECT`, SOCKS5, and MITM upstream
connections
- keep configured upstream proxy hops on the existing proxy path
- add direct-connector coverage for allowed and rejected local targets
## Security impact
Direct proxy egress now rechecks the resolved socket address before
connecting, closing the gap between hostname policy evaluation and the
final network target.
## Verification
- `cargo test -p codex-network-proxy`
---------
Co-authored-by: Codex <noreply@openai.com>
## Summary
This PR replaces the legacy network allow/deny list model with explicit
rule maps for domains and unix sockets across managed requirements,
permissions profiles, the network proxy config, and the app server
protocol.
Concretely, it:
- introduces typed domain (`allow` / `deny`) and unix socket permission
(`allow` / `none`) entries instead of separate `allowed_domains`,
`denied_domains`, and `allow_unix_sockets` lists
- updates config loading, managed requirements merging, and exec-policy
overlays to read and upsert rule entries consistently
- exposes the new shape through protocol/schema outputs, debug surfaces,
and app-server config APIs
- rejects the legacy list-based keys and updates docs/tests to reflect
the new config format
## Why
The previous representation split related network policy across multiple
parallel lists, which made merging and overriding rules harder to reason
about. Moving to explicit keyed permission maps gives us a single source
of truth per host/socket entry, makes allow/deny precedence clearer, and
gives protocol consumers access to the full rule state instead of
derived projections only.
## Backward Compatibility
### Backward compatible
- Managed requirements still accept the legacy
`experimental_network.allowed_domains`,
`experimental_network.denied_domains`, and
`experimental_network.allow_unix_sockets` fields. They are normalized
into the new canonical `domains` and `unix_sockets` maps internally.
- App-server v2 still deserializes legacy `allowedDomains`,
`deniedDomains`, and `allowUnixSockets` payloads, so older clients can
continue reading managed network requirements.
- App-server v2 responses still populate `allowedDomains`,
`deniedDomains`, and `allowUnixSockets` as legacy compatibility views
derived from the canonical maps.
- `managed_allowed_domains_only` keeps the same behavior after
normalization. Legacy managed allowlists still participate in the same
enforcement path as canonical `domains` entries.
### Not backward compatible
- Permissions profiles under `[permissions.<profile>.network]` no longer
accept the legacy list-based keys. Those configs must use the canonical
`[domains]` and `[unix_sockets]` tables instead of `allowed_domains`,
`denied_domains`, or `allow_unix_sockets`.
- Managed `experimental_network` config cannot mix canonical and legacy
forms in the same block. For example, `domains` cannot be combined with
`allowed_domains` or `denied_domains`, and `unix_sockets` cannot be
combined with `allow_unix_sockets`.
- The canonical format can express explicit `"none"` entries for unix
sockets, but those entries do not round-trip through the legacy
compatibility fields because the legacy fields only represent allow/deny
lists.
## Testing
`/target/debug/codex sandbox macos --log-denials /bin/zsh -c 'curl
https://www.example.com' ` gives 200 with config
```
[permissions.workspace.network.domains]
"www.example.com" = "allow"
```
and fails when set to deny: `curl: (56) CONNECT tunnel failed, response
403`.
Also tested backward compatibility path by verifying that adding the
following to `/etc/codex/requirements.toml` works:
```
[experimental_network]
allowed_domains = ["www.example.com"]
```
## Problem
Today `codex-network-proxy` rejects a global `*` in
`network.allowed_domains`, so there is no static way to configure a
denylist-only posture for public hosts. Users have to enumerate broad
allowlist patterns instead.
## Approach
- Make global wildcard acceptance field-specific: `allowed_domains` can
use `*`, while `denied_domains` still rejects a global wildcard.
- Keep the existing evaluation order, so explicit denies still win first
and local/private protections still apply unless separately enabled.
- Add coverage for the denylist-only behavior and update the README to
document it.
## Validation
- `just fmt`
- `cargo test -p codex-network-proxy` (full run had one unrelated flaky
telemetry test:
`network_policy::tests::emit_block_decision_audit_event_emits_non_domain_event`;
reran in isolation and it passed)
- `cargo test -p codex-network-proxy
network_policy::tests::emit_block_decision_audit_event_emits_non_domain_event
-- --exact --nocapture`
- `just fix -p codex-network-proxy`
- `just argument-comment-lint`
## Summary
- treat `requirements.toml` `allowed_domains` and `denied_domains` as
managed network baselines for the proxy
- in restricted modes by default, build the effective runtime policy
from the managed baseline plus user-configured allowlist and denylist
entries, so common hosts can be pre-approved without blocking later user
expansion
- add `experimental_network.managed_allowed_domains_only = true` to pin
the effective allowlist to managed entries, ignore user allowlist
additions, and hard-deny non-managed domains without prompting
- apply `managed_allowed_domains_only` anywhere managed network
enforcement is active, including full access, while continuing to
respect denied domains from all sources
- add regression coverage for merged-baseline behavior, managed-only
behavior, and full-access managed-only enforcement
## Behavior
Assuming `requirements.toml` defines both
`experimental_network.allowed_domains` and
`experimental_network.denied_domains`.
### Default mode
- By default, the effective allowlist is
`experimental_network.allowed_domains` plus user or persisted allowlist
additions.
- By default, the effective denylist is
`experimental_network.denied_domains` plus user or persisted denylist
additions.
- Allowlist misses can go through the network approval flow.
- Explicit denylist hits and local or private-network blocks are still
hard-denied.
- When `experimental_network.managed_allowed_domains_only = true`, only
managed `allowed_domains` are respected, user allowlist additions are
ignored, and non-managed domains are hard-denied without prompting.
- Denied domains continue to be respected from all sources.
### Full access
- With managed requirements present, the effective allowlist is pinned
to `experimental_network.allowed_domains`.
- With managed requirements present, the effective denylist is pinned to
`experimental_network.denied_domains`.
- There is no allowlist-miss approval path in full access.
- Explicit denylist hits are hard-denied.
- `experimental_network.managed_allowed_domains_only = true` now also
applies in full access, so managed-only behavior remains in effect
anywhere managed network enforcement is active.
## Summary
- reject the global `*` domain pattern in proxy allow/deny lists and
managed constraints introduced for testing earlier
- keep exact hosts plus scoped wildcards like `*.example.com` and
`**.example.com`
- update docs and regression tests for the new invalid-config behavior
## Summary
- delete the network proxy admin server and its runtime listener/task
plumbing
- remove the admin endpoint config, runtime, requirement, protocol,
schema, and debug-surface fields
- update proxy docs to reflect the remaining HTTP and SOCKS listeners
only
**PR Summary**
This PR adds embedded-only OTEL policy audit logging for
`codex-network-proxy` and threads audit metadata from `codex-core` into
managed proxy startup.
### What changed
- Added structured audit event emission in `network_policy.rs` with
target `codex_otel.network_proxy`.
- Emitted:
- `codex.network_proxy.domain_policy_decision` once per domain-policy
evaluation.
- `codex.network_proxy.block_decision` for non-domain denies.
- Added required policy/network fields, RFC3339 UTC millisecond
`event.timestamp`, and fallback defaults (`http.request.method="none"`,
`client.address="unknown"`).
- Added non-domain deny audit emission in HTTP/SOCKS handlers for
mode-guard and proxy-state denies, including unix-socket deny paths.
- Added `REASON_UNIX_SOCKET_UNSUPPORTED` and used it for unsupported
unix-socket auditing.
- Added `NetworkProxyAuditMetadata` to runtime/state, re-exported from
`lib.rs` and `state.rs`.
- Added `start_proxy_with_audit_metadata(...)` in core config, with
`start_proxy()` delegating to default metadata.
- Wired metadata construction in `codex.rs` from session/auth context,
including originator sanitization for OTEL-safe tagging.
- Updated `network-proxy/README.md` with embedded-mode audit schema and
behavior notes.
- Refactored HTTP block-audit emission to a small local helper to reduce
duplication.
- Preserved existing unix-socket proxy-disabled host/path behavior for
responses and blocked history while using an audit-only endpoint
override (`server.address="unix-socket"`, `server.port=0`).
### Explicit exclusions
- No standalone proxy OTEL startup work.
- No `main.rs` binary wiring.
- No `standalone_otel.rs`.
- No standalone docs/tests.
### Tests
- Extended `network_policy.rs` tests for event mapping, metadata
propagation, fallbacks, timestamp format, and target prefix.
- Extended HTTP tests to assert unix-socket deny block audit events.
- Extended SOCKS tests to cover deny emission from handler deny
branches.
- Added/updated core tests to verify audit metadata threading into
managed proxy state.
### Validation run
- `just fmt`
- `cargo test -p codex-network-proxy` ✅
- `cargo test -p codex-core` ran with one unrelated flaky timeout
(`shell_snapshot::tests::snapshot_shell_does_not_inherit_stdin`), and
the test passed when rerun directly ✅
---------
Co-authored-by: viyatb-oai <viyatb@openai.com>
## Summary
Adds support for a Unix socket escape hatch so we can bypass socket
allowlisting when explicitly enabled.
## Description
* added a new flag, `network.dangerously_allow_all_unix_sockets` as an
explicit escape hatch
* In codex-network-proxy, enabling that flag now allows any absolute
Unix socket path from x-unix-socket instead of requiring each path to be
explicitly allowlisted. Relative paths are still rejected.
* updated the macOS seatbelt path in core so it enforces the same Unix
socket behavior:
* allowlisted sockets generate explicit network* subpath rules
* allow-all generates a broad network* (subpath "/") rule
---------
Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
## Summary
When network requests were blocked, downstream code often had to infer
ask vs deny from free-form response text. That was brittle and led to
incorrect approval behavior.
This PR fixes the proxy side so blocked decisions are structured and
request metadata survives reliably.
## Description
- Blocked proxy responses now carry consistent structured policy
decision data.
- Request attempt metadata is preserved across proxy env paths
(including ALL_PROXY flows).
- Header stripping was tightened so we still remove unsafe forwarding
headers, but keep metadata needed for policy handling.
- Block messages were clarified (for example, allowlist miss vs explicit
deny).
- Added unified violation log entries so policy failures can be
inspected in one place.
- Added/updated tests for these behaviors.
---------
Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Currently, `codex-network-proxy` depends on `codex-core`, but this
should be the other way around. As a first step, refactor out
`ConfigReloader`, which should make it easier to move
`codex-rs/network-proxy/src/state.rs` to `codex-core` in a subsequent
commit.
Summary:
- Rename config table from network_proxy to network.
- Flatten allowed_domains, denied_domains, allow_unix_sockets, and
allow_local_binding onto NetworkProxySettings.
- Update runtime, state constraints, tests, and README to the new config
shape.
Load requirements from Codex Backend. It only does this for enterprise
customers signed in with ChatGPT.
Todo in follow-up PRs:
* Add to app-server and exec too
* Switch from fail-open to fail-closed on failure
Constructors with long param lists can be hard to reason about when a
number of the args are `None`, in practice. Introducing a struct to use
as the args type helps make things more self-documenting.
This add a new crate, `codex-network-proxy`, a local network proxy
service used by Codex to enforce fine-grained network policy (domain
allow/deny) and to surface blocked network events for interactive
approvals.
- New crate: `codex-rs/network-proxy/` (`codex-network-proxy` binary +
library)
- Core capabilities:
- HTTP proxy support (including CONNECT tunneling)
- SOCKS5 proxy support (in the later PR)
- policy evaluation (allowed/denied domain lists; denylist wins;
wildcard support)
- small admin API for polling/reload/mode changes
- optional MITM support for HTTPS CONNECT to enforce “limited mode”
method restrictions (later PR)
Will follow up integration with codex in subsequent PRs.
## Testing
- `cd codex-rs && cargo build -p codex-network-proxy`
- `cd codex-rs && cargo run -p codex-network-proxy -- proxy`
evawong-oai ·
viyatb-oai ·
Celia Chen ·
rreichel3-oai ·
mcgrew-oai ·
Michael Bolin ·
gt-oai ·