Updated
September 10, 2026
Spacelift excels at GitOps-based Terraform automation but lacks native CI/CD integration, runtime inputs, and cross-lifecycle policy enforcement. Harness IaCM unifies infrastructure provisioning, pipeline orchestration, governance, and cost controls on a single platform.
Feature Comparison
| Feature | Harness | Spacelift |
|---|---|---|
| Platform & Deployment | ||
| SaaS offering | ||
| Self-hosted agents | ||
| On-premises / air-gapped | Self-Managed Enterprise Edition with full SaaS parity | Self-hosted available; some enterprise features require additional configuration |
| Native CI/CD integration | Same unified pipeline engine as Harness CI/CD | Requires external CI/CD tooling or custom YAML scripts |
| Native GitOps | ||
| Public APIs | ||
| Predictable pricing | Workspace-based pricing | User seat and concurrency-based tiers; costs can scale unpredictably at enterprise scale |
| IaC Tool Support | ||
| Terraform | ||
| OpenTofu | ||
| Terragrunt | GA with drift detection, OPA, STO integration, and PR comments | |
| Pulumi | ||
| CloudFormation | ||
| AWS CDK | Beta | |
| Ansible | Native Ansible plugin with WinRM, dynamic inventory, and preflight validation | |
| Kubernetes (native) | Via CD GitOps integration | |
| Workspace & State Management | ||
| Git-based workspace | ||
| CLI-based workspace (remote backend) | harness iacm plan CLI available; full remote backend support evolving | |
| State management | ||
| Remote execution (speculative plan) | ||
| Terraform HTTP backend | ||
| Show state / Show diff | ||
| Download state | ||
| Lock state (complete execution) | ||
| Drift detection | ||
| Resource Graph | Resource-level dashboard analytics | Stack dependency graph available; resource-level graph limited |
| Workspace Explorer | ||
| Ephemeral Infra (TTL) | ||
| Variables & Configuration | ||
| Variable management | ||
| Runtime inputs | Native, first-class pipeline feature | Not natively supported; requires external automation |
| Load variables from Git | ||
| Project/account-level variable sets | Account, org, and project-level variable sets | Contexts for shared variable injection |
| Custom images | ||
| Secret management | ||
| External secret management (Vault, etc.) | Native Vault connector for workspaces | Via OIDC Vault integration |
| As Code (for all configuration) | ||
| Governance & Policy | ||
| OPA policies | Full cross-lifecycle enforcement | Infrastructure-scoped OPA policies |
| Policy-as-code generation | Harness AI generates, explains, and updates OPA Rego from natural language across the full platform | |
| Native policy enforcement | ||
| Policy registry | ||
| Flexible approvals | ||
| RBAC | ||
| Custom roles | ||
| SAML / SSO | ||
| Audit trail | ||
| Templates & Modules | ||
| Template library | Workspace templates with override support | Blueprints and stack templates |
| Module registry | ||
| Module registry testing | Enforced as part of the module publishing workflow; test pipelines auto-trigger on new commits | No native test enforcement in the registry |
| Composite execution (chained pipeline) | Stack dependencies support triggering; full pipeline chaining requires custom logic | |
| Pipeline & Workflow | ||
| PR workflow | ||
| Run arbitrary tasks | ||
| Run steps/stages in parallel | ||
| Concurrency | ||
| Notifications | ||
| Plugin ecosystem | ||
| Cost & Reporting | ||
| Cost estimation | Inline in PR and approval gates | Via Infracost integration (manual setup) |
| Reports | ||
| AI Features | ||
| Natural language infra provisioning | Spacelift Intent; direct NL → cloud API provisioning for non-critical workloads | |
| AI DevOps Agent (pipeline generation) | Creates and edits pipelines, stages, and IaC workflows across all Harness modules | No equivalent cross-platform AI pipeline agent |
| AI Remediation Agent | Automated remediation and drift response | |
| AI Blast Radius Agent | Roadmap — analyzes changes to identify downstream impact across systems | |
| Software Delivery Knowledge Graph | Unified graph across code, infra, builds, deploys, security, cost, incidents | |
| MCP server integration | Harness MCP Server and Harness Unified Agent for IDE-to-platform automation | Unified MCP endpoint exposing GraphQL and Intent tools |
Key Differentiators
Why teams choose Harness IaCM over Spacelift
Native CI/CD Integration
Built on the same pipeline engine as Harness CI and CD. Provisioning, security scans, cost gates, and approvals are all first-class pipeline stages. One pipeline provisions infrastructure, runs STO security checks, deploys, and rolls back on failure.
Stack-centric GitOps model. Security scanning, testing, and deployment steps require custom YAML scripts or external CI/CD tools. Teams must stitch integrations together as environments scale.
AI-Native Platform
Harness AI runs on a Software Delivery Knowledge Graph ingesting signals across code, infra, builds, deploys, security, incidents, and cloud spend. The DevOps Agent generates OPA policies and full IaCM pipelines from natural language. The Remediation Agent automates drift remediation. The AI Blast Radius Agent (roadmap) identifies downstream impact before changes are applied. All agents operate through the Harness Unified Agent and Harness MCP Server.
Spacelift Intelligence adds natural language provisioning (Intent) for non-critical workloads. AI is scoped to provisioning and plan policies, not the broader delivery lifecycle.
Tested Module Registry
Testing is enforced as part of the module publishing workflow. Modules must pass a test pipeline before they can be reused. Webhook triggers fire test pipelines automatically on new commits.
Private module registry available, but testing is not enforced natively. Teams rely on external CI pipelines to validate modules before promotion.
Unified Pipeline Orchestration
Infrastructure provisioning, application deployment, security testing, cost gates, and approval workflows all run on the same pipeline engine. One pipeline can provision infrastructure, run STO security checks, deploy the application, and roll back on failure — no handoff to an external tool required.
Stack dependencies and trigger policies handle infra-level sequencing well. But Spacelift is designed to work alongside external CI/CD tools — app builds, security scans, and deployment stages live in GitHub Actions, GitLab CI, or Jenkins. Teams must maintain two systems and stitch them together.
Runtime Inputs
Runtime inputs are a first-class pipeline feature. Any variable or configuration value can be flagged for user input at trigger time. Combined with account, org, and project-level variable sets, teams get dynamic control without modifying pipeline YAML.
No native runtime input support. Variable overrides require contexts, .tfvars files in Git, or external automation.
Decision Guide
Spacelift is good for
- Your team is Terraform/OpenTofu-centric and GitOps-native, and infrastructure automation is its own separate concern with no need for deep CI/CD or application deployment integration
- You need native multi-tool IaC support today — Pulumi, CloudFormation, and Kubernetes — alongside Terraform and Terragrunt in a single platform
- You want Spacelift Intent's agentic natural language provisioning for rapid prototyping of non-critical infrastructure, with a path to promote resources into full IaC code
- Your team heavily uses Terragrunt run-all workflows and values Spacelift's mature multi-stack dependency graph and concurrent execution model
Harness is best for
- Your team needs to connect infrastructure provisioning directly with CI/CD pipelines, security scans, and deployment workflows — without bolting on external tooling or maintaining custom YAML glue
- You require Harness AI capabilities — OPA policy generation, intelligent pipeline authoring, automated drift remediation, and FinOps cost enforcement — working uniformly across infrastructure, pipelines, and security stages
- Your platform team needs to define, test, and reuse infrastructure modules at scale with enforced testing pipelines and workspace templates with override support
- You're an enterprise with complex multi-team governance requirements: account/org/project variable sets, flexible runtime inputs, and cross-lifecycle audit trails on a single platform
Summary
Spacelift is a solid GitOps-native IaC platform for teams running infrastructure automation in isolation, but requires external CI/CD tools to connect provisioning with deployment, security, and approvals. Harness IaCM natively integrates across the full software delivery lifecycle with provisioning, CD, security, and governance on one pipeline engine, a tested module registry, unified policy enforcement, and AI agents for policy as code authoring, drift remediation, and security remediation.
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