From acf4bd70fb38b16fd2dff7790f2f3c2122e0251a Mon Sep 17 00:00:00 2001
From: Ryan Ghadimi <ghadimir@github.com>
Date: Wed, 14 Jan 2026 17:01:59 +0000
Subject: [PATCH] Add handling for 429s from cache service

---
 .../src/internal/shared/cacheTwirpClient.ts   | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/packages/cache/src/internal/shared/cacheTwirpClient.ts b/packages/cache/src/internal/shared/cacheTwirpClient.ts
index f6c2af61..ade1b8c9 100644
--- a/packages/cache/src/internal/shared/cacheTwirpClient.ts
+++ b/packages/cache/src/internal/shared/cacheTwirpClient.ts
@@ -1,4 +1,4 @@
-import {info, debug} from '@actions/core'
+import {info, debug, warning} from '@actions/core'
 import {getUserAgentString} from './user-agent'
 import {NetworkError, UsageError} from './errors'
 import {getCacheServiceURL} from '../config'
@@ -109,6 +109,20 @@ class CacheServiceClient implements Rpc {
 
           errorMessage = `${errorMessage}: ${body.msg}`
         }
+
+        // Handle rate limiting - don't retry, just warn and exit
+        if (statusCode === HttpCodes.TooManyRequests) {
+          const retryAfterHeader = response.message.headers['retry-after']
+          if (retryAfterHeader) {
+            const parsedSeconds = parseInt(retryAfterHeader, 10)
+            if (!isNaN(parsedSeconds) && parsedSeconds > 0) {
+              warning(
+                `You've hit a rate limit, your rate limit will reset in ${parsedSeconds} seconds`
+              )
+            }
+          }
+          throw new Error(`Rate limited: ${errorMessage}`)
+        }
       } catch (error) {
         if (error instanceof SyntaxError) {
           debug(`Raw Body: ${rawBody}`)
@@ -162,8 +176,7 @@ class CacheServiceClient implements Rpc {
       HttpCodes.BadGateway,
       HttpCodes.GatewayTimeout,
       HttpCodes.InternalServerError,
-      HttpCodes.ServiceUnavailable,
-      HttpCodes.TooManyRequests
+      HttpCodes.ServiceUnavailable
     ]
 
     return retryableStatusCodes.includes(statusCode)