Browser agents lack completion contracts — formalize authority & side-effects

Many developer and automation teams building browser-based agents lack a formal way to define and verify what an agent is authorized to do and what side-effects it may incur. That ambiguity creates security, compliance, and reliability gaps for roughly 1.2M teams that spend an average of $8K on security/policy tooling and runtime controls, contributing to a $9.6B addressable market. You could build a lightweight "completion contract" system that pairs a machine-readable contract with runtime enforcement in the browser—specifying authority scopes, allowed DOM mutations and API calls, and expected structured outputs (function calls)—plus SDKs to bind contracts to LLM prompts and CI checks to validate simulated runs. Complement that with a developer console and a policy manager that produce cryptographically verifiable audit trails, plus adapters for common RPA and automation frameworks to reduce adoption friction. This is an attractive moment because agentification of workflows, richer function-calling outputs, and RPA convergence make it practical to verify behavior against formal contracts, and enterprises are increasingly demanding auditable runtime controls. The market score (90/100) and revenue potential (88/100) reflect that buyers are ready to allocate budget toward tools that demonstrably reduce incidents and simplify compliance. To differentiate in a medium-competition landscape, pursue a standards-first spec, extremely low-friction browser integrations (extension/sidecar/proxy), and developer-friendly validation during development and at runtime, while offering enterprise features like policy templates, SSO, and e-discovery hooks. The honest challenges are getting broad spec adoption and handling heterogeneous web apps and privacy constraints, but a pragmatic GTM focused on security and automation teams with clear ROI metrics (reduced incidents, fewer rollbacks) can make this a viable product.