Inspiration
What it does
How we built it
Inspiration
WebMCP gives agents structured access to websites. Causal Mission Gate explores the next question: what should happen when an agent can act, but the user still owns the authority to commit important effects?
The project is built around one principle:
Capability does not imply authority.
A user should be able to state a simple objective without having to engineer every operational step. The system should manage complexity, autonomy, evidence, and escalation while preserving human sovereignty over critical effects.
What it does
Causal Mission Gate converts simple user intent into a governed mission.
A request such as:
Review this release and leave it ready if it is safe.
becomes a structured mission contract with:
- objective and success conditions
- operating profile
- causal deliberation mode
- policy boundary
- reversibility requirements
- escalation conditions
- exact human authority for critical effects
Routine preparation can run autonomously under management-by-exception.
Critical effects cannot proceed until the human approves the exact current intent.
That approval is:
- bound to the mission
- bound to the current version
- bound to the exact intent digest
- time-limited
- single-use
After execution, the system produces an attributable receipt and verifies the audit chain.
How we built it
The application is built with Node.js, JavaScript, Docker, and a WebMCP tool surface registered through document.modelContext.registerTool().
The WebMCP surface exposes 11 bounded tools for:
- system inspection
- mission shaping
- governance queue inspection
- attention planning
- executive digest
- provisional observation
- governed execution
- evidence verification
- decision support
Human authority actions are deliberately excluded from agent tools.
Approval, rejection, delegation, ratification, and rollback remain human-controlled.
Server-side governance validates:
- mission state
- expected version
- exact intent digest
- approval freshness
- one-time use
- policy constraints
- evidence integrity
Challenges we ran into
One important failure appeared during the final deployment test.
A valid exact approval expired before execution. The server correctly denied the request, but the mission remained in an approved state without a clean path back to human review.
Instead of bypassing the control, we treated the failure as a state-machine defect.
The fix introduced an explicit transition:
APPROVED → expiry → WAITING_APPROVAL
The system now preserves the same exact intent, records the expiration event, and requires a new human authorization.
A regression test was added, bringing the final suite to 90 passing tests.
The lesson was:
Expiry is not merely a denial condition; it is a state transition.
Accomplishments that we're proud of
- 11 WebMCP tools with a deliberately bounded capability surface
- exact-effect human authorization
- one-time and expiring approvals
- management by exception
- causal deliberation
- attributable execution receipts
- hash-chained audit evidence
- 90 passing automated tests
- a public live deployment
- a complete flow from simple intent to governed PASS
What we learned
High autonomy does not require giving up human sovereignty.
The important design boundary is not simply “human in the loop” versus “fully autonomous”.
Authority, autonomy, visibility, and initiative can be separated.
An agent can prepare, inspect, evaluate, and execute within policy while still being unable to manufacture the authority required for a critical effect.
What's next
The next step is extending the same governance model to longer-running autonomous missions where human decisions may be delayed.
Reversible provisional effects, causal attention management, and durable evidence can allow useful work to continue without silently converting autonomy into authority.
The broader goal is simple:
The user states intent. The system manages complexity. Causality governs deliberation. Policy governs action. Evidence proves the result.
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