---
name: gear-gstd-api-map-f9e19809286a
description: Use when a builder needs to choose the right gstd API for messaging, execution, reservations, async reply flows, or program creation, and trace that API to gcore or gsys when behavior must be confirmed. Do not use for Vara.eth or ethexe-first work, non-Gear repositories, or broad runtime-maintenance tasks.
---

# Gear gstd API Map

## Goal

Keep design work API-first: start from `gstd`, then drop to `gcore` or `gsys` only when you need to confirm limits, gas shape, or low-level behavior.

## Inputs

- `../../references/gear-execution-model.md` — execution model and block lifecycle
- `../../references/gear-messaging-and-replies.md` — message flow and reply semantics
- `../../references/gear-gas-reservations-and-waitlist.md` — gas reservations and waitlist
- `../../references/gear-gstd-api-and-syscalls.md` — full API surface and syscall mapping

## Route Here When

- a spec or architecture note needs to know whether a Gear program can send, await replies, self-schedule, reserve gas, or create child programs
- a builder is choosing between typed payloads, raw bytes, staged push-plus-commit, or input-forwarding APIs
- a design depends on `#[gstd::async_main]`, `_for_reply` flows, delayed work, `ReservationId`, or `prog::*`
- a debugging pass needs to confirm which `gr_*` syscall family a high-level API actually reaches
- a `send_for_reply` targets a hardcoded non-program `ActorId` (staking, proxy, BLS12-381, ETH bridge); route to `gear-builtin-actors` for the per-actor request shape and reply decoding

## Working Model

1. Start from builder intent, not from raw syscalls.
2. Choose the `gstd` family: `msg`, `exec`, `prog`, reservations, or async helpers.
3. Prefer the highest-level API that preserves the contract: typed send and reply first, bytes only for intentional raw payload paths or codec debugging.
4. Check design constraints: block-delayed execution, reply deposit, reservation lifetime, waitlist exposure, gas budget, and Sails Header routing stability for Sails clients.
5. Drop to `gcore` to confirm wrapper behavior and to `gsys` only when you need exact syscall names, fallibility, or control-vs-get distinctions.

## API Quick Reference

| Module | Key APIs | When to Use |
|--------|----------|-------------|
| `msg` | `send`, `reply`, `send_delayed`, `send_for_reply`, `send_bytes`, push-plus-commit | Sending messages, replying, delayed dispatch, awaiting replies |
| `exec` | `gas_available`, `block_height`, `wait`, `wait_for`, `wake`, `reply_deposit`, `exit` | Reading execution context, parking in waitlist, waking actors |
| `prog` | `create_program`, `create_program_bytes`, create-for-reply | Creating child programs with optional delay and gas limits |
| reservations | `ReservationId::reserve`, `.unreserve`, reservation pools | Future-block work that must keep a gas budget alive |

## Guardrails

- Prefer `gstd` as the default public API for standard Gear/Vara builders.
- Treat raw `gsys::gr_*` names as confirmation tools, not the first design vocabulary.
- Keep design notes phrased in message flow, replies, blocks, and contracts, not in syscall sequences.
- If a Sails route depends on generated clients, preserve that route contract even for delayed or self-messaging paths.
- Stop if the task is really about runtime benchmarking, syscall-maintenance coverage, or ethexe-only behavior.


---
Source attribution: gear-foundation
Original project: https://github.com/gear-foundation/vara-skills/blob/44c1454141ececc8ef3a88903b625260f370c4de/skills/gear-gstd-api-map/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Mega AI Hub.

## Upstream license notice

MIT License

Copyright (c) 2026 Gear Foundation

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Mega AI Hub resource metadata

Creator / publisher: gear-foundation
Original project: https://github.com/gear-foundation/vara-skills/blob/44c1454141ececc8ef3a88903b625260f370c4de/skills/gear-gstd-api-map/SKILL.md
Attribution basis: Source repository record

Fields of work: Development & Engineering, Product Management
Roles: Backend Developer, Full-Stack Developer, Product Manager
Specialties: API, Backend
Tools: Gstd
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: 601a6c89f2ddabaa303612c8673dfc68b842420a030daa53d4790f73a427dcdc