## Summary
This makes the advertised mid-run steering path real: users can send
append or interrupt steering messages through the API, CLI, and web UI,
and the worker delivers them to live API-mode agent sessions or buffers
them for the next session. The change adds the control protocol, session
interrupt machinery, workflow hub, server route/OpenAPI/client updates,
and UI feedback needed for the whole path.
### Plan Summary
- Add `SteerKind`/`run.steer` wire protocol and `POST /runs/{id}/steer`
- Deliver steers through subprocess JSONL or the in-process
`SteeringHub`
- Support append and interrupt behavior in agent sessions, with bounded
buffering and events
- Expose steering in the CLI/web UI and surface SSE toasts
## Flow
```mermaid
flowchart TB
UI["CLI / Web UI"] --> API["POST /runs/{id}/steer"]
API -->|"subprocess transport"| Control["Worker control JSONL"]
API -->|"in-process transport"| Hub["SteeringHub"]
Control --> Hub
Hub -->|"active API sessions"| Session["SessionControlHandle"]
Hub -->|"no active session"| Pending["Pending buffer"]
Pending -->|"first future API session"| Session
Session --> Agent["Session round loop"]
Agent --> Events["RunEvent stream"]
Events --> UI
```
## What changed and why
- Agent sessions now expose a lightweight `SessionControlHandle`, drain
steering at the top of each round, and use a replaceable round
cancellation token for interrupts. LLM waits are cancelled promptly,
while tool execution observes cancellation cooperatively so every
committed `tool_use` still gets a matching `tool_result`.
- `SteeringHub` owns active API session registration, broadcast
delivery, pending buffering, FIFO queue caps, and steering
lifecycle/drop events. A completion coordinator closes the
final-response race without introducing a workflow dependency into the
agent crate.
- The server route replaces the 501 stub, validates run state and
best-effort CLI-only steerability, and forwards through either
subprocess control JSONL or the in-process hub. OpenAPI and generated
clients now include the request type.
- The CLI and web UI can send append or interrupt steers. Run detail and
board views open the new composer, and shared SSE subscriptions now
support per-subscriber event callbacks so invalidation and steering
toasts can coexist on one EventSource.
## Review notes
- Steering actors stay on top-level `RunEvent.actor`; event props only
carry steering kind/drop metadata.
- Buffered steers replay as append messages to the first API session
that registers after an empty-active period. Per-stage targeting remains
out of scope.
- CLI-mode agent stages are still not steerable; the server returns a
best-effort 409 when all active agent stages are CLI-mode, while the
worker hub remains the authoritative safety net.
- No persistence or schema migration is required; active and pending
steering state is in memory.
- New tests focus on protocol round-trips, hub buffering/bounds, session
steering-loop behavior, SSE fanout, and basic server rejection paths.
⚒️ Generated with [Fabro](https://fabro.sh)
---------
Co-authored-by: Fabro <noreply@fabro.sh>
Co-authored-by: Bryan Helmkamp <bryan@brynary.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This change makes bulk `fabro model test` run configured model checks
concurrently instead of serially. A new `--jobs/-j` flag (defaulting to
4, minimum 1) controls the concurrency bound; the single-model path
(`--model <MODEL>`) is unaffected. Under the hood, the serial `for` loop
over configured models is replaced with a
`futures::stream::buffer_unordered(jobs)` pipeline that clones the
shared-state `Client` per request. Completed results carry their
original list index and are sorted before rendering, so final stdout
table rows and JSON output remain in listing order regardless of which
requests finish first.
Three new integration tests verify the concurrency behavior using an
inline Axum harness with a `ConcurrencyGate` barrier. The gate holds all
in-flight requests until the expected number arrive simultaneously, then
releases them, letting tests assert `max_in_flight` exactly rather than
relying on timing. The ordering test goes further by assigning
reverse-listing response delays so the last-listed model always finishes
first; if the index sort were dropped, the JSON result order would
invert and the assertion would fail. A 15-second gate timeout ensures a
regression to serial execution surfaces as a clear `max_in_flight == 1`
failure rather than a hung test.
Existing behavior is fully preserved: unconfigured models are still
skipped without a POST, a configured model returning `skip` after
listing is still a failure, `--deep` uses the same `--jobs` value, and
`--jobs 1` reproduces the previous serial behavior for users hitting
provider rate limits.
### Fabro Details
<details>
<summary>Ran 9 stages in 30m 52s for $19.61</summary>
| Stage | Duration | Cost | Retries |
|---|---|---|---|
| start | 0s | – | 0 |
| toolchain | 1s | – | 0 |
| preflight_compile | 2m 8s | – | 0 |
| preflight_lint | 2m 21s | – | 0 |
| implement | 8m 56s | $3.87 | 0 |
| simplify_opus | 7m 55s | $1.43 | 0 |
| simplify_gpt | 6m 58s | $14.32 | 0 |
| verify | 1m 49s | – | 0 |
| fmt | 2s | – | 0 |
| **Total** | **30m 52s** | **$19.61** | **0** |
</details>
<details>
<summary>Ran <code>ImplementPlan.fabro</code> (12 nodes and 15
edges)</summary>
```dot
digraph ImplementPlan {
graph [
goal="Implement and simplify",
model_stylesheet="
* { model: claude-opus-4-7; }
"
]
rankdir=LR
start [shape=Mdiamond, label="Start"]
exit [shape=Msquare, label="Exit"]
toolchain [label="Toolchain", shape=parallelogram, script="command -v cargo >/dev/null || { curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y && sudo ln -sf $HOME/.cargo/bin/* /usr/local/bin/; }; cargo --version 2>&1", max_retries=0]
preflight_compile [label="Preflight Compile", shape=parallelogram, script="cargo check -q --workspace 2>&1", max_retries=0]
preflight_lint [label="Preflight Lint", shape=parallelogram, script="cargo +nightly-2026-04-14 clippy -q --workspace --all-targets -- -D warnings 2>&1", max_retries=0]
fix_lints [label="Fix Lints", prompt="The preflight lint step failed. Read the build output from context and fix all clippy lint warnings.", max_visits=3]
implement [label="Implement", prompt="Read the plan file referenced in the goal and implement every step. Make all the code changes described in the plan. Use red/green TDD."]
simplify_opus [label="Simplify (Opus)", prompt="@prompts/simplify.md"]
simplify_gpt [label="Simplify (GPT-55)", prompt="@prompts/simplify.md", model="gpt-55"]
verify [label="Verify", shape=parallelogram, script="cargo +nightly-2026-04-14 clippy -q --workspace --all-targets -- -D warnings 2>&1 && cargo nextest run --cargo-quiet --workspace --status-level fail 2>&1 && cargo dev docs refresh 2>&1 && cargo dev docs check 2>&1", goal_gate=true, retry_target="fixup"]
fixup [label="Fixup", prompt="The verify step failed. Read the build output from context and fix all clippy lint warnings, test failures, and generated docs errors.", max_visits=3]
fmt [label="Format", shape=parallelogram, script="cargo +nightly-2026-04-14 fmt --all 2>&1", max_retries=0]
start -> toolchain
toolchain -> preflight_compile [condition="outcome=succeeded"]
toolchain -> exit
preflight_compile -> preflight_lint [condition="outcome=succeeded"]
preflight_compile -> exit
preflight_lint -> implement [condition="outcome=succeeded"]
preflight_lint -> fix_lints
fix_lints -> preflight_lint
implement -> simplify_opus -> simplify_gpt -> verify
verify -> fmt [condition="outcome=succeeded"]
verify -> fixup
fixup -> verify
fmt -> exit
}
```
</details>
⚒️ Generated with [Fabro](https://fabro.sh)
---------
Co-authored-by: Fabro <noreply@fabro.sh>
Mintlify parses pages as MDX and rejects HTML-style `<!-- ... -->`
comments, which broke the docs deployment on cli.mdx with a parse
error. Switch the generator fences (and the matching markers in the
two reference pages and the dev test fixtures) to `{/* ... */}` so
Mintlify can parse them.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Drop async from validate::run after the preflight refactor removed all
awaits, replace absolute paths and a one-liner helper in
manifest_validation, swap a redundant to_path_buf for clone in a test,
and regenerate cli.mdx so docs check stays green.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Ensure local runs use the worktree checkpoint path by default, expose source and sandbox paths in API/web surfaces, and remove dead fork/rewind push controls. Update docs for clone-based sandboxes and durable checkpoint timelines.
Invert the docs convention so the Mintlify-published site lives under
docs/public/ and internal artifacts (strategy docs, brainstorms, plans,
etc.) sit at docs/ root or docs/internal/. Tools that default to writing
into docs/ now land in the catch-all instead of leaking into the
published tree.
- Move Mintlify content (administration/, agents/, api-reference/,
changelog/, core-concepts/, examples/, execution/, getting-started/,
human-tools/, integrations/, languages/, reference/, tutorials/,
workflows/, images/, logo/, docs.json, favicon.svg, dot-highlight.js)
into docs/public/.
- Collapse docs-internal/ into docs/internal/.
- Update Rust path references (fabro-api/build.rs, fabro-server,
fabro-dev), TypeScript generator arg, CI path filters, clippy.toml
reasons, AGENTS.md/CLAUDE.md, and README.md image refs.
Mintlify dashboard project root must be updated to docs/public/ in a
follow-up. .mintignore move/trim and .claude/skills/ updates land in a
separate commit.
