| name | asupersync-mega-skill |
| description | Replace Tokio stacks with Asupersync. Use when migrating Tokio/axum/hyper/tonic apps, designing Cx/region services, debugging internals, or classifying proof/ATP evidence. |
Asupersync Mega Skill
Asupersync is a spec-first, cancel-correct, capability-secure async runtime for Rust. Not a Tokio wrapper -- a broad, support-class-scoped replacement for native Asupersync designs, with stronger guarantees around structured concurrency, obligation tracking, deterministic testing, and capability security. Exact adapter, web, browser, protocol, and benchmark parity must still be checked against live docs and proof artifacts.
This skill is primarily for agents integrating Asupersync into other projects or extracting maximum architectural leverage from it in greenfield systems. It also covers repo-internal work when that is the actual task.
For codebase orientation, types, module map, and workspace layout see SOURCE-MAP.md.
Quick Orient
Minimal bootstrap:
use asupersync::{Cx, Error};
use asupersync::runtime::RuntimeBuilder;
async fn main_task(cx: &Cx) -> Result<(), Error> {
cx.trace("running");
cx.checkpoint()?;
Ok(())
}
fn main() -> Result<(), Error> {
let runtime = RuntimeBuilder::current_thread().build()?;
let result = runtime.block_on(runtime.handle().spawn(async {
let cx = Cx::current().expect("runtime task Cx");
main_task(&cx).await
}));
result?;
Ok(())
}
This is the current production teaching seam: RuntimeBuilder creates the
runtime, block_on installs an ambient runtime context, runtime-spawned tasks
run with a runtime-owned Cx, and app code receives &Cx. Do not teach
Cx::for_request() as production bootstrap; it is test/internal-harness
material. For services, prefer request/call regions at boundaries, then
graduate to AppSpec + supervision when the topology is long-lived. For
admission-sensitive bootstrap, use try_spawn / try_spawn_with_cx and handle
SpawnError explicitly.
Where to focus first:
- Lead with core runtime,
Cx/Scope, cancellation, obligations, channels, sync, time, lab/DPOR, and observability
- For ordinary services, build next on native
service, web, grpc, database, and supervision surfaces
- Treat Browser Edition, QUIC/H3, messaging, remote/distributed, and RaptorQ as requirement-driven lanes, not default starting points
Default recommendation order for most real projects:
- core runtime +
Cx + Scope
- native
service / web / grpc boundaries
- native database and actor/supervision surfaces as needed
- deterministic tests and diagnostics from the start
Do not lead with Browser Edition, QUIC/H3, messaging, remote/distributed, or RaptorQ unless the target project explicitly needs those capabilities.
Full surface guidance: STACK-SURFACES.md.
Start Here
Choose one lane before touching code:
- Native greenfield
Build directly on
RuntimeBuilder, Cx, Scope, LabRuntime, and optional AppSpec.
- Brownfield native migration
Rewrite your app's async seams around
&Cx, region-owned tasks, cancel-aware primitives, and deterministic tests.
For serious migrations, run the repo's read-only migration readiness planner
and use its verdict, proof commands, semantic recommendations, and operator
phase plan as inputs rather than treating cargo tree grep output as a plan.
- Boundary interop
Use
asupersync-tokio-compat only for crates you cannot remove yet. Keep Tokio out of core business logic.
Default rule:
- prefer native Asupersync surfaces,
- use compat only as a quarantine boundary,
- plan to remove compat once the stubborn dependency is gone.
Non-Negotiables
- Do not treat Asupersync as an executor swap.
- Put
&Cx first in async APIs you control.
- Use
Scope and child regions for owned work. Avoid detached background tasks.
- Use
Cx::spawn / Cx::spawn_in for ordinary region-owned task creation.
Scope::spawn_registered is a lower-level boot/test path for callers already
holding &mut RuntimeState.
- Add
cx.checkpoint() in loops, retry bodies, long handlers, and shutdown-sensitive code.
- Prefer cancel-aware primitives and two-phase effects.
- Use deterministic tests as part of normal development, not as optional polish.
- Treat
Cx::for_testing() and Cx::for_request() as test/internal harness
paths, not production architecture.
- Keep Tokio and Tokio-only crates behind explicit adapter modules if you must keep them at all.
Leverage, Not Just Migration
If the target system is doing real work, do not stop after "the code compiles on Asupersync."
Canonical Spine
- Bootstrap:
runtime::RuntimeBuilder, Runtime, RuntimeHandle
- App code:
Cx, Cx::spawn, Cx::spawn_in, Scope child regions
- Tests:
test_utils::{run_test, run_test_with_cx}, LabRuntime, LabConfig,
LabRunReport
- Service boundaries:
web::request_region::{RequestRegion, RequestContext}, grpc::CallContext::with_cx(...)
- Higher-level apps:
app::AppSpec, actor, gen_server, supervision, spork
Start with RuntimeBuilder + Cx + Scope. Graduate to AppSpec + supervision when you need restart policy, named workers, or explicit application topology.
Macro guidance: scope! binds the current-region scope; it does not create a
fresh child-region boundary. spawn! needs runtime state. Manual APIs are still
the safest authoritative path when semantics matter.
Current generated API-map anchors to remember:
- outbound HTTP:
http::Client / http::HttpClient fluent request builders,
- deterministic lab:
lab::ScenarioRunner and lab::CancellationInjector,
- web metadata and middleware:
web::Router::routes, web::RouteInfo,
web::middleware::{CatchPanicLayer, CompressionLayer, RequestTraceLayer, TimeoutLayer}, plus web::Router::layer,
- ATP/daemon, RaptorQ, observability, Spork,
runtime::RuntimeBuilder, and
Cx + Scope.
Refresh these from /data/projects/asupersync/artifacts/api_surface_map_v1.json
before making precise public-surface claims.
Standard Workflow
- Inventory all
tokio::*, tokio-util, hyper, axum, tonic, reqwest, sqlx, quinn, h3, rdkafka, and related dependencies.
- Classify each dependency as: native replacement, compat holdout, or deliberate workaround.
- Replace runtime bootstrap first.
- Thread
&Cx through your own async APIs.
- Replace detached spawning with region-owned work.
- Replace sync/time/net/io/channel/web/db/messaging surfaces domain by domain.
- Add deterministic tests while migrating, not after.
- Remove compat boundaries as soon as the underlying dependency no longer needs them.
Reference Index
Quick Router: Start Here For Your Task
Other focused references live under references/ for adoption lanes, compat
bridges, anti-patterns, budgets/outcomes/capabilities, lock ordering,
performance, supervision, networking, browser frameworks, distributed rigor,
observability, and troubleshooting. Use SOURCE-MAP.md
when you need the full codebase navigation map.
Specialized refs: ADOPTION-LANES,
COMPAT-BOUNDARY,
COMPAT-BRIDGE,
ANTI-PATTERNS,
CHANNELS-SYNC-INTERNALS,
LOCK-ORDERING,
NETWORKING-PROTOCOL-STACK,
DB-MESSAGING-FS-PROCESS,
DISTRIBUTED-AND-RIGOR,
RAPTORQ-DISTRIBUTED,
MATHEMATICAL-FOUNDATIONS,
BROWSER-WASM, and
BROWSER-FRAMEWORKS.
Validation
When changing code:
- run the host project's normal formatter, compiler, lint, and test suite,
- add deterministic integration tests for the migrated path,
- verify cancellation, shutdown, and resource-release behavior,
- verify that no core domain code still depends on Tokio if the goal is full native adoption.
If working inside the Asupersync repo itself, read live TESTING_FOR_AGENTS.md
before choosing proof. Use rch exec -- env CARGO_TARGET_DIR=... for
remote-required lanes, preserve the RCH build id / target dir / artifact root /
dirty-tree state in handoff, and do not turn a local fallback into green proof
for a lane whose manifest says remote proof is required. See
REPO-CONTRIBUTOR-GUIDE.md for mandatory
compiler checks and testing discipline.
Operating Rules
- When forced to choose between "minimal code churn" and "native Asupersync semantics", choose the latter unless the task explicitly calls for a temporary boundary bridge.
- Forbidden crates in runtime/core
src/: tokio, hyper, reqwest,
axum, tower except scoped adapter feature paths, async-std, and smol.
Satellite, test, fuzz, benchmark, and compat carve-outs must stay documented
and proof-checked.
- Inside the Asupersync repo: follow live
AGENTS.md. Never delete files
without permission. Work only on main; do not introduce legacy-branch
references except the exact required mirror command, if still present there.
- Inside the Asupersync repo, trust
AGENTS.md, README.md,
CHANGELOG.md, artifacts/api_surface_map_v1.json, proof-lane manifests,
proof-status snapshots, and benchmark matrix artifacts over remembered API
shapes.
- Classify every repo-internal proof through
artifacts/proof_lane_manifest_v1.json and
artifacts/proof_status_snapshot_v1.json before making any "green" claim.
A broad check/clippy result is not enough when a Phase 6, benchmark,
golden, flamegraph, or proof-note artifact gate applies.
- ATP benchmark claims require tuned-rsync, release-
atp, crypto-symmetric,
rate-capped, SHA/tamper-checked evidence. A single current cell can support a
scoped regression claim; headline "beats rsync" claims need whole-matrix
evidence. Compile success or sha_ok alone is not a win.
Evidence-First Operator Cards
Use these compact operators for volatile repo-internal claims:
- Live-doc refresh: before any Asupersync-internal API, proof, or ATP claim,
read live
AGENTS.md, README.md, TESTING_FOR_AGENTS.md, CHANGELOG.md,
the relevant source, and the relevant artifact/ledger rows. Do not rely on
this skill's dated examples as authority.
- Claim gate: classify the evidence as
banked, scoped-cell-only,
parity, correct-but-slower, candidate, stale, blocked, or
failed. Say the no-claim boundary in the same breath as the positive claim.
- ATP gate: require tuned rsync, release
atp, crypto-symmetric setup,
rate caps, SHA/tamper fail-closed checks, and current matrix/ledger evidence.
sha_ok, cargo check, or one favorable stale cell is not a benchmark win.
- Proof-lane classifier: map each repo-internal proof to
artifacts/proof_lane_manifest_v1.json and
artifacts/proof_status_snapshot_v1.json; preserve RCH build id, target dir,
artifact path, and dirty-tree state for cited proof.
- Migration planner router: for downstream migrations, run the read-only
migration readiness planner when deciding whether/how to migrate; treat
scripts/audit-target.sh as quick inventory only.
Current ATP evidence snapshot (refresh before citing): encrypted QUIC
MATRIX-205/206/210 has a measured 50M/good/encrypted win and
5G/perfect/encrypted correctness unblock, but no banked encrypted-large or
full-matrix win; 500M/perfect/encrypted, 50M/bad/encrypted, and 5G
receiver RSS remain open. RQ/nocrypto MATRIX-207/208/209 banked exactly one
new positive cell: 500M/broken/nocrypto atp median 564.77s, sha-ok 3/3 plus
a confirming fourth rep, versus tuned rsync median 574.46s. MATRIX-210
QUIC drain-cap tuning and MATRIX-211 packed-member commit batching are
implementation landings, not banked benchmark wins without fresh matrix proof.