Messages sent with `followup_task` already arrive at their target
recipient promptly (at message boundaries while sampling, or after the
pending tool call completes) -- having `interrupt` is not worth the
added complexity.
## Summary
- Thread `agent_max_threads` into `ToolsConfig` and
`SpawnAgentToolOptions`.
- Render the configured `max_concurrent_threads_per_session` value in
the MultiAgentV2 `spawn_agent` description.
- Cover the description text in `codex-tools` unit tests and
`codex-core` tool spec tests.
## Validation
- `just fmt`
- `cargo test -p codex-tools`
- `cargo test -p codex-core spawn_agent_description`
- `git diff --check`
## Notes
- `cargo test -p codex-core` was also attempted, but unrelated
environment-sensitive tests failed with the active local environment.
Examples: approvals reviewer defaults observed `AutoReview` instead of
`User`, request-permissions event tests did not emit events, and
proxy-env tests saw `http://127.0.0.1:50604` from the active proxy
environment.
Co-authored-by: Codex <noreply@openai.com>
This updates the spawn-agent tool contract so subagents are presented as
inheriting the parent model by default. The visible model list is now
framed as optional overrides, the model parameter tells callers to leave
it unset and the delegation guidance no longer nudges models toward
picking a smaller/mini override.
Fixes reports that 5.4 would occasionally pick 5.2 or lower as
sub-agents.
Allow multi_agent_v2 features to have its own temporary configuration
under `[features.multi_agent_v2]`
```
[features.multi_agent_v2]
enabled = true
usage_hint_enabled = false
usage_hint_text = "Custom delegation guidance."
hide_spawn_agent_metadata = true
```
Absent `usage_hint_text` means use the default hint.
```
[features]
multi_agent_v2 = true
```
still works as the boolean shorthand.
Fast Mode status was still tied to one model name in the TUI and
model-list plumbing. This changes the model metadata shape so a model
can advertise additional speed tiers, carries that field through the
app-server model list, and uses it to decide when to show Fast Mode
status.
For people using Codex, the behavior is intended to stay the same for
existing models. Fast Mode still requires the existing signed-in /
feature-gated path; the difference is that the UI can now recognize any
model the model list marks as Fast-capable, instead of requiring a new
client-side slug check.
## Summary
- switch MultiAgentV2 send_message to accept a single message string
instead of items
- keep the old assign_task item parser in place for the next branch
- update send_message schema/spec and focused handler tests
## Verification
- cargo test -p codex-tools
send_message_tool_requires_message_and_uses_submission_output
- cargo test -p codex-core multi_agent_v2_send_message
- just fix -p codex-tools
- just fix -p codex-core
- just argument-comment-lint
---------
Co-authored-by: Codex <noreply@openai.com>
Adds this:
```
properties.insert(
"fork_turns".to_string(),
JsonSchema::String {
description: Some(
"Optional MultiAgentV2 fork mode. Use `none`, `all`, or a positive integer string such as `3` to fork only the most recent turns."
.to_string(),
),
},
);
```
---------
Co-authored-by: Codex <noreply@openai.com>
## Why
The recent `codex-tools` migration steps have moved shared tool models
and low-coupling spec helpers out of `codex-core`, but
`core/src/tools/spec.rs` still owned a large block of pure
collaboration-tool spec construction. Those builders do not need session
state or runtime behavior; they only need a small amount of core-owned
configuration injected at the seam.
Moving that cohesive slice into `codex-tools` makes the crate boundary
more honest and removes a substantial amount of passive tool-spec logic
from `codex-core` without trying to move the runtime-coupled multi-agent
handlers at the same time.
## What changed
- added `agent_tool.rs`, `request_user_input_tool.rs`, and
`agent_job_tool.rs` to `codex-tools`, with sibling `*_tests.rs` coverage
and an exports-only `lib.rs`
- moved the pure `ToolSpec` builders for:
- collaboration tools such as `spawn_agent`, `send_input`,
`send_message`, `assign_task`, `resume_agent`, `wait_agent`,
`list_agents`, and `close_agent`
- `request_user_input`
- agent-job specs `spawn_agents_on_csv` and `report_agent_job_result`
- rewired `core/src/tools/spec.rs` to call the extracted builders while
still supplying the core-owned inputs, such as spawn-agent role
descriptions and wait timeout bounds
- updated the `core/src/tools/spec.rs` seam tests to build expected
collaboration specs through `codex-tools`
- updated `codex-rs/tools/README.md` so the crate documentation reflects
the broader collaboration-tool boundary
## Test plan
- `CARGO_TARGET_DIR=/tmp/codex-tools-collab-specs cargo test -p
codex-tools`
- `CARGO_TARGET_DIR=/tmp/codex-core-collab-specs cargo test -p
codex-core --lib tools::spec::`
- `just fix -p codex-tools -p codex-core`
- `just argument-comment-lint`
## References
- #15923
- #15928
- #15944
- #15953
- #16031
- #16047
- #16129
- #16132
- #16138
