sails-rust-implementer

name	sails-rust-implementer
description	Use when approved Gear or Vara tasks require Rust or Sails code changes in a real workspace. Do not use when the spec or architecture is still unsettled, or when the task is only review or deployment.

Sails Rust Implementer

Overview

Implement approved tasks in Sails-first Rust workspaces without freelancing new scope. If the task touches a released contract, preserve public routes, reply shapes, emitted events, and generated-client expectations unless the approved architecture explicitly changes them.

Inputs

• ../../references/sails-cheatsheet.md — core Sails patterns and APIs
• ../../references/sails-rs-imports.md — import paths for sails-rs types
• ../../references/delayed-message-pattern.md — delayed self-message recipe
• ../../references/vara-domain-overview.md — Vara domain context
• ../../references/gear-sails-production-patterns.md — production patterns
• ../../references/gear-messaging-and-replies.md — messaging and reply flows
• ../../references/gear-gas-reservations-and-waitlist.md — gas and waitlist
• ../../references/sails-syscall-mapping.md — Syscall::* API mapping (use instead of raw gcore::*/msg::*/exec::*)

Additional references by task type:

• Token work: ../../references/awesome-sails-token-patterns.md
• Released contract changes: ../../references/contract-interface-evolution.md

Consume the approved spec, architecture, and tasks artifacts before changing code.

If the target crate explicitly builds an ethexe path, stop and hand back to a dedicated ethexe workflow instead of extending this standard Sails pack.

Workflow

1. Confirm the task is already specified and architecture-approved.
2. Identify the smallest code change that satisfies the current task.
3. Match the current Sails release conventions before improvising: public service routes use #[export], events use emit_event, and shared types use #[sails_type] (expands to Encode + Decode + TypeInfo + ReflectHash with correct crate paths). Prefer #[sails_type] over manual derives for all service types, command/query params, and event payloads. Use #[sails_type(crate = my_crate)] when re-exporting from a different crate.
4. Preserve released routes, reply shapes, emitted events, IDL expectations, and client-facing contract stability unless the task explicitly changes them.
5. Keep failure handling aligned with Gear/Vara async semantics.
6. Hand local verification to the gtest loop before claiming the task is done.

Guardrails

• Do not redesign the feature while coding.
• Prefer Sails-level interfaces over raw payload work unless the task says otherwise.
• Keep constructor shape and state ownership consistent with the approved architecture instead of inventing a new storage pattern mid-implementation.
• Use generated clients or equivalent Sails Header-aware encoding for normal Sails calls; do not substitute bare raw structs for constructor or service payloads.
• If the feature needs a delayed self-message, use the shared payload recipe and the Syscall::message_source() == Syscall::program_id() guard pattern instead of ad hoc routing bytes.
• Preserve fail-fast command behavior; panic on fatal stateful command-path failures instead of introducing partial-commit recovery.
• Use Syscall::gas_available() for remaining-gas checks in execution paths.
• Use Syscall::* for all runtime accessors instead of raw gcore::*, msg::*, or exec::* calls. Full mapping: ../../references/sails-syscall-mapping.md (listed in Inputs).
• Treat value flow, replies, and async ordering as first-class behavior.
• Stop and hand back to planning if implementation uncovers a real architecture gap.
• Do not change a released public route shape in place unless the approved architecture explicitly allows it.
• Do not change a released event payload in place without explicit versioning or cutover guidance.
• Do not assume IDL regeneration alone makes a breaking interface change safe.
• Do not leave old-version write behavior undefined if the architecture requires ReadOnly or write-disable handling.

#[export] Usage

All public service methods must be annotated with #[export]. For standard (non-ethexe) Sails apps, no transport flags are needed — #[export] enables SCALE transport by default. Transport flags (scale, ethabi, payable) are ethexe-specific; see the sails-ethexe-implementer skill for details.