diff --git a/vendor/go.opentelemetry.io/auto/sdk/limit.go b/vendor/go.opentelemetry.io/auto/sdk/limit.go
new file mode 100644
index 0000000..86babf1
--- /dev/null
+++ b/vendor/go.opentelemetry.io/auto/sdk/limit.go
@@ -0,0 +1,94 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package sdk
+
+import (
+	"log/slog"
+	"os"
+	"strconv"
+)
+
+// maxSpan are the span limits resolved during startup.
+var maxSpan = newSpanLimits()
+
+type spanLimits struct {
+	// Attrs is the number of allowed attributes for a span.
+	//
+	// This is resolved from the environment variable value for the
+	// OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT key if it exists. Otherwise, the
+	// environment variable value for OTEL_ATTRIBUTE_COUNT_LIMIT, or 128 if
+	// that is not set, is used.
+	Attrs int
+	// AttrValueLen is the maximum attribute value length allowed for a span.
+	//
+	// This is resolved from the environment variable value for the
+	// OTEL_SPAN_ATTRIBUTE_VALUE_LENGTH_LIMIT key if it exists. Otherwise, the
+	// environment variable value for OTEL_ATTRIBUTE_VALUE_LENGTH_LIMIT, or -1
+	// if that is not set, is used.
+	AttrValueLen int
+	// Events is the number of allowed events for a span.
+	//
+	// This is resolved from the environment variable value for the
+	// OTEL_SPAN_EVENT_COUNT_LIMIT key, or 128 is used if that is not set.
+	Events int
+	// EventAttrs is the number of allowed attributes for a span event.
+	//
+	// The is resolved from the environment variable value for the
+	// OTEL_EVENT_ATTRIBUTE_COUNT_LIMIT key, or 128 is used if that is not set.
+	EventAttrs int
+	// Links is the number of allowed Links for a span.
+	//
+	// This is resolved from the environment variable value for the
+	// OTEL_SPAN_LINK_COUNT_LIMIT, or 128 is used if that is not set.
+	Links int
+	// LinkAttrs is the number of allowed attributes for a span link.
+	//
+	// This is resolved from the environment variable value for the
+	// OTEL_LINK_ATTRIBUTE_COUNT_LIMIT, or 128 is used if that is not set.
+	LinkAttrs int
+}
+
+func newSpanLimits() spanLimits {
+	return spanLimits{
+		Attrs: firstEnv(
+			128,
+			"OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT",
+			"OTEL_ATTRIBUTE_COUNT_LIMIT",
+		),
+		AttrValueLen: firstEnv(
+			-1, // Unlimited.
+			"OTEL_SPAN_ATTRIBUTE_VALUE_LENGTH_LIMIT",
+			"OTEL_ATTRIBUTE_VALUE_LENGTH_LIMIT",
+		),
+		Events:     firstEnv(128, "OTEL_SPAN_EVENT_COUNT_LIMIT"),
+		EventAttrs: firstEnv(128, "OTEL_EVENT_ATTRIBUTE_COUNT_LIMIT"),
+		Links:      firstEnv(128, "OTEL_SPAN_LINK_COUNT_LIMIT"),
+		LinkAttrs:  firstEnv(128, "OTEL_LINK_ATTRIBUTE_COUNT_LIMIT"),
+	}
+}
+
+// firstEnv returns the parsed integer value of the first matching environment
+// variable from keys. The defaultVal is returned if the value is not an
+// integer or no match is found.
+func firstEnv(defaultVal int, keys ...string) int {
+	for _, key := range keys {
+		strV := os.Getenv(key)
+		if strV == "" {
+			continue
+		}
+
+		v, err := strconv.Atoi(strV)
+		if err == nil {
+			return v
+		}
+		slog.Warn(
+			"invalid limit environment variable",
+			"error", err,
+			"key", key,
+			"value", strV,
+		)
+	}
+
+	return defaultVal
+}