jif ee9e0f6387 Pin MCP runtimes to model steps (#30101) ...

## Why

An MCP refresh can replace the session's current manager while a model
step is still running. The step must execute calls through the same
manager whose tools it advertised.

## Boundary

```text
current session MCP runtime
          |
          | capture once for this model step
          v
StepContext.mcp
  - exact MCP config
  - exact connection manager
  - exact runtime environment context
```

```rust
pub struct McpRuntimeSnapshot {
    config: Arc<McpConfig>,
    manager: Arc<McpConnectionManager>,
    runtime_context: McpRuntimeContext,
}
```

## Example

```text
step A captures runtime A and advertises A's tools
refresh publishes runtime B
step A tool call -> runtime A
next step        -> runtime B
```

Capturing the snapshot is only an `Arc` clone. It does not restart MCPs
or make an RPC.

## What changes

- Captures one MCP runtime in `StepContext`.
- Uses it for tool planning, tool calls, resources, approvals, connector
attribution, and elicitation.
- Publishes replacement runtimes atomically.
- Lets an old runtime live only while an in-flight step or request still
holds its `Arc`.

Most of this diff is mechanical routing from the session-global manager
to `step_context.mcp`; it does not introduce selected-plugin discovery
yet.

## What does not change

- No plugin or extension migration.
- No new MCP cache policy.
- No environment file watching.
- No client sharing between separate managers.

## Stack

1. Extension-owned World State sections.
2. Project executor skills through World State.
3. **This PR:** pin one MCP runtime to each model step.
4. Project selected MCP/app/connector metadata by environment
availability.
5. One end-to-end integration scenario.

ee9e0f6387 · 2026-06-26 00:53:07 +01:00

History

..

common

core: expose permission profile to shell tools (#29941)

2026-06-25 19:00:23 +00:00

remote_env_windows

core: load AGENTS.md from foreign environments (#28958)

2026-06-18 15:06:23 -07:00

suite

Pin MCP runtimes to model steps (#30101)

2026-06-26 00:53:07 +01:00

all.rs

[codex] Use expect in integration tests (#28441)

2026-06-15 21:53:47 -07:00

responses_headers.rs

feat: use run agent task auth for inference (#19051)

2026-06-24 22:31:41 -07:00