From bc7c11c0eb609b083ebe8d8129d6d341fffc787c Mon Sep 17 00:00:00 2001
From: scttfrdmn <3011922+scttfrdmn@users.noreply.github.com>
Date: Mon, 10 Aug 2026 13:51:57 -0700
Subject: [PATCH] feat(aws): add Capabilities.VCPUs (default vCPU count per
 instance type)

Populated from DescribeInstanceTypes' VCpuInfo.DefaultVCpus. Lets a
caller (spawn's sweep orchestrator, spawn#492) convert a per-family
vCPU quota into an instance-count ceiling without re-implementing
pkg/quotas.getVCPUCount's name-based size-suffix parsing, which its
own fallback comment already documents as unreliable for non-linear
sizes (p6-b200.48xlarge, metal sizes).
---
 CHANGELOG.md      |  9 +++++++++
 pkg/aws/client.go | 10 ++++++++++
 2 files changed, 19 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 54c41ef..e34d23b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+- **`Capabilities.VCPUs`** — the instance type's default vCPU count
+  (`DescribeInstanceTypes`' `VCpuInfo.DefaultVCpus`), so a caller can convert a
+  per-family vCPU quota (`pkg/quotas.QuotaInfo`) into an instance-count ceiling
+  without re-parsing the type's size suffix — the same name-based guessing
+  `pkg/quotas.getVCPUCount` already falls back to, which `obtainability.go`'s
+  own comment flags as unreliable for non-linear sizes (spawn#492).
+
 ### Fixed
 - **`quotas.CanLaunch`'s Spot path now tracks current Spot usage** instead of
   only confirming a request fits the *full* Spot quota (#132). `QuotaInfo`
@@ -19,6 +27,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   instances got a false "fits" for 2 more, since 16 ≤ 64 (the full quota) in
   isolation — the actual launch then failed with
   `MaxSpotInstanceCountExceeded` with zero prior warning.
+>>>>>>> 3117a40 (feat(aws): add Capabilities.VCPUs (default vCPU count per instance type))
 
 ## [0.48.1] - 2026-08-07
 
diff --git a/pkg/aws/client.go b/pkg/aws/client.go
index 7c600b5..a3f7ce3 100644
--- a/pkg/aws/client.go
+++ b/pkg/aws/client.go
@@ -594,6 +594,13 @@ type Capabilities struct {
 	NestedVirtualization bool     `json:"nested_virtualization"`   // can run KVM/Hyper-V in-instance
 	GPUs                 int32    `json:"gpus,omitempty"`
 	BareMetal            bool     `json:"bare_metal"`
+	// VCPUs is the instance type's default vCPU count (EC2's VCpuInfo.DefaultVCpus).
+	// Lets a caller convert a per-family vCPU quota (pkg/quotas.QuotaInfo) into an
+	// instance count without re-parsing the type's size suffix — the same
+	// name-based guessing pkg/quotas.getVCPUCount uses as a last-resort fallback,
+	// which obtainability.go's own comment already flags as unreliable for
+	// non-linear sizes (p6-b200.48xlarge, metal sizes). spawn#492.
+	VCPUs int32 `json:"vcpus,omitempty"`
 }
 
 // GetCapabilities returns feature support for a single instance type in the
@@ -643,6 +650,9 @@ func (c *Client) GetCapabilities(ctx context.Context, instanceType, region strin
 			caps.Architectures = append(caps.Architectures, string(a))
 		}
 	}
+	if it.VCpuInfo != nil && it.VCpuInfo.DefaultVCpus != nil {
+		caps.VCPUs = *it.VCpuInfo.DefaultVCpus
+	}
 	return caps, nil
 }