Cisco pyATS vs Invariant

Cisco pyATS is a Python framework for network testing, automation, and validation, available free under the Apache 2.0 license. It supports sanity, feature, solution, system, and scale test and verification workflows, with reusable data-driven tests ranging from simple checks to complex asynchronous suites. Genie libraries provide device connectivity, parsers, APIs, platform-agnostic feature models, reusable test cases, and a YAML-driven test runner. Built-in device libraries cover Cisco IOS, IOS XE, IOS XR, NX-OS, and ASA; plugins and extensions can add other platforms. Connections can use CLI, NETCONF, or RESTCONF. XPRESSO manages test suites, environments, testbeds, resources, live test views, and archived results with comparisons and analytics. It supports on-demand, bundled, and scheduled runs through Jenkins and Docker backends. Cisco also documents Ansible community integrations and out-of-the-box RobotFramework support. pyATS runs on Linux and macOS and supports self-hosted deployment. Cisco says more than 75% of its codebase is open source on GitHub. Email support is best-effort and usually receives a reply within a day.

Invariant validates network configurations against connectivity and security rules in a cross-vendor digital twin. It builds the model from configuration files, so direct access to routers or switches is not required. Users define policies in YAML and evaluate them against network snapshots, including proposed changes before deployment. Results can report policy violations and failures affecting critical flows. Scheduled network scans can trigger incident alerts with virtual traceroutes and virtual route-table differences. The service lists Cisco, Juniper, Palo Alto, and AWS among supported vendors, and integrations including Jenkins, GitHub Actions, LibreNMS, Netmiko, Aerleon, Capirca, IPAM, and SIEM workflows. A CLI, SDK, and API support automation. Listed protocols include BGP, OSPF, IPSec, NAT, policy-based routing, VPN, ACL, and VLAN. Invariant offers hybrid deployment and web/API access. The Basic account is free, billed as a free Basic account with effectively no usage limits. Higher tiers add SSO, larger device counts, and preview features.