Freedom251 › Contract Testing Tools
SpecShield
What SpecShield is
SpecShield helps API teams identify contract changes that could disrupt services already using an API. It compares OpenAPI descriptions and flags removed endpoints, tightened types, and newly required fields on pull requests. Its GitHub App posts a diff and compatibility verdict as a pull request check, and can block a merge when a registered consumer would break. A consumer registry records which services depend on an API so the deploy gate can assess compatibility. SpecShield also scores OpenAPI descriptions against OWASP and design rulesets on a 0–100 scale with a letter grade. Teams can connect it through a GitHub App or Action, a CLI for CI systems, an IntelliJ plugin, SARIF output, or an MCP server for AI agents. The Free plan costs nothing forever and includes one user, unlimited spec comparisons, one GitHub App pull request check, and seven-day compare history. Team costs $89 a month, or $900/year ($75/mo billed annually), for up to 10 users; it adds a consumer registry, can-i-deploy gate, audit trail, bidirectional contract testing, Slack alerts, shared workspace, and RBAC. The free browser diff accepts OpenAPI 3.0 and 3.1 in JSON or YAML and says submitted specs are compared in the request without being persisted.
Who it suits
SpecShield is for backend, mobile, platform, microservices, and release engineering teams shipping OpenAPI APIs. It suits teams that want pull request compatibility checks and a record of which services depend on an API.
What it does well
- Flags removed endpoints, tightened types, and newly required fields.
- GitHub checks show a diff and compatibility verdict.
- Can block merges when a consumer would break.
- Grades OpenAPI descriptions against OWASP and design rulesets.
- Free plan allows unlimited spec comparisons.
What to know first
- Free plan is limited to one user.
- Free plan includes one GitHub App pull request check.
- Free compare history lasts seven days.
- Team plan is limited to 10 users.
Limits
Free is limited to one user, seven-day compare history, and one GitHub App pull request check. Team supports up to 10 users; Enterprise offers unlimited users.
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| SpecShield Free | Free forever · 1 user · unlimited spec comparisons · 1 GitHub App PR check · 7-day compare history · community support | Free |
| SpecShield Team | $89/month, or $900/year ($75/mo billed annually) · Up to 10 users · consumer registry · can-i-deploy gate · audit trail · BDCT · Slack alerts · shared workspace · RBAC | $89 a month |
| SpecShield Enterprise | Custom pricing · Unlimited users · SSO · on-prem/private-cloud on request · advanced RBAC · audit-log export · dedicated onboarding · SLA | On request |
As specshield.io lists them, read 29 Sept 2026. The maker's own page has the final word.
Getting started
- Visit the SpecShield website.
- Start with the Free plan or choose Team.
- Submit OpenAPI 3.0 or 3.1 JSON or YAML specs to the free browser diff.
- Connect the GitHub App for pull request checks.
- Use the CLI, GitHub Action, IntelliJ plugin, SARIF output, or MCP server if those routes fit your workflow.
Verdict
Choose SpecShield if your team ships OpenAPI APIs and needs pull request checks tied to known consumers. The Free plan covers individual comparisons, while Team adds shared governance and deployment controls. Look elsewhere if your team needs more than 10 users on Team or requires Enterprise pricing to be stated upfront.
Questions
Does SpecShield have a free plan?
Yes. The Free plan is free forever and includes one user, unlimited spec comparisons, one GitHub App pull request check, seven-day compare history, and community support.
How much does the Team plan cost?
Team costs $89 a month, or $900/year ($75/mo billed annually). It supports up to 10 users.
What API specifications does the browser diff accept?
It accepts OpenAPI specifications in JSON or YAML, including OpenAPI 3.0 and 3.1.
What integrations are available?
SpecShield offers a GitHub App and Action, a CLI for CI systems, an IntelliJ plugin, SARIF output, and an MCP server for AI agents.
Does SpecShield support GraphQL?
GraphQL support is listed. The described browser diff accepts OpenAPI JSON or YAML.
What does Enterprise include?
Enterprise includes unlimited users, SSO, on-premises or private-cloud deployment on request, advanced RBAC, audit-log export, dedicated onboarding, and a dedicated SLA. Its price is custom.
Facts from SpecShield's own pages
- Breaking change detection
- It flags removed endpoints, tightened types, and newly required fields on pull requests. · specshield.io, 29 Sept 2026
- Consumer registry
- The consumer registry records which services depend on an API so the deploy gate can assess compatibility. · specshield.io, 29 Sept 2026
- Free diff privacy
- The free browser diff compares submitted specs in the request and says it does not persist them. · specshield.io, 29 Sept 2026
- Free plan limit
- The Free plan is limited to one user and includes seven-day compare history and one GitHub App pull request check. · specshield.io, 29 Sept 2026
- GitHub checks
- The GitHub App posts pull request checks with a diff and compatibility verdict, and can block merges when a consumer would break. · specshield.io, 29 Sept 2026
- Governance
- It scores OpenAPI descriptions against OWASP and design rulesets on a 0–100 scale with a letter grade. · specshield.io, 29 Sept 2026
- Integrations
- The product offers a GitHub App and Action, CLI for CI systems, IntelliJ plugin, SARIF output, and an MCP server for AI agents. · specshield.io, 29 Sept 2026
- Purpose
- SpecShield compares OpenAPI descriptions to flag changes that could break existing API consumers and reports results as GitHub checks. · specshield.io, 29 Sept 2026
- Security evidence
- The maker says its audit log records logins, invites, role changes, contract publishes, deploy verdicts, and breaking-change detections in an append-only table, with CSV export. · specshield.io, 29 Sept 2026
- Support
- Free includes community support, Team includes priority email support, and Enterprise includes a dedicated SLA. · specshield.io, 29 Sept 2026
- Supported specs
- The browser diff accepts OpenAPI specifications in JSON or YAML, including OpenAPI 3.0 and 3.1. · specshield.io, 29 Sept 2026
- Team features
- The Team plan includes an enforced can-i-deploy gate, audit trail, bidirectional contract testing, Slack alerts, shared workspace, and RBAC. · specshield.io, 29 Sept 2026
- Who it is for
- The maker describes the product for backend, mobile, platform, microservices, and release engineering teams shipping OpenAPI APIs. · specshield.io, 29 Sept 2026
Where SpecShield stands on Freedom251
- Contract Testing Tools#16 of 22