diff --git a/apps/harness/Dockerfile b/apps/harness/Dockerfile
index 6ce8355..3898784 100644
--- a/apps/harness/Dockerfile
+++ b/apps/harness/Dockerfile
@@ -17,10 +17,11 @@ WORKDIR /app
 ENV NODE_ENV=production
 
 # System tools needed by agent executors
-RUN apk add --no-cache git github-cli
+RUN apk add --no-cache git github-cli curl
 
 # Agent CLIs (installed globally before dropping to non-root)
-RUN npm install -g @anthropic-ai/claude-code @openai/codex
+RUN npm install -g @anthropic-ai/claude-code @openai/codex \
+  && curl -fsSL https://opencode.ai/install | sh
 
 RUN addgroup --system --gid 1001 nodejs
 RUN adduser --system --uid 1001 nextjs