Apache SkyWalking vs AppSignal

Apache SkyWalking is a free, self-hosted observability platform for cloud-native systems and AI workloads. It brings traces, metrics, logs, and profiling together to help users explore services, Kubernetes, and infrastructure through topology, telemetry, profiles, and alerts. For AI workloads, users can inspect model and MCP call latency and token rates, and review agent conversations, tool calls, and recorded file changes. The project lists agents for Java, Python, NodeJS, Go, Rust, PHP, Ruby, Nginx LUA, Kong, and client-side JavaScript. Its integrations and ecosystem include OpenTelemetry OTLP, Istio, Envoy, Kubernetes, Grafana, and MCP. BanyanDB is described as a database for ingesting, analyzing, and storing observability data. Docker installation instructions cover Linux, macOS, WSL, and Windows PowerShell. Horizon UI supports SkyWalking natively since v11 and partially for v10. Its security documentation covers Content-Security-Policy, strict session cookies, no-store API responses, and optional login auditing. Apache source releases are official artifacts, with PGP or SHA512 verification recommended; the GraalVM distribution is marked experimental.

AppSignal is a cloud application-monitoring service for developers, with error tracking, performance monitoring, logs, and tracing. Error tracking groups exceptions with backtraces and the deployment linked to each issue. Performance monitoring covers response times, throughput, slow endpoints, and slow queries. Log management provides full-text search, attribute filters, saved queries, live tail, and pattern-based alerts. Distributed tracing, transaction tracing, and log correlation are available. AppSignal lists support for Ruby, Elixir, Node.js, JavaScript, Python, Go, Java, PHP, and Rust, with integrations including Slack, GitHub, Jira, Linear, GitLab, and PagerDuty. Its MCP server lets AI assistants such as Claude, Cursor, and Zed query production errors, traces, and deploys. The free plan costs nothing and includes 30K requests, 1GB logging, five-day retention, and unlimited users, teams, applications, and dashboards. Paid access is $279 a year, billed yearly at $23.25/month, with 250K requests per month. A 30-day full-featured trial requires no credit card. AppSignal says it does not charge overages or stop monitoring when limits are crossed.