Code runtime

Stacksona for LangGraph

Put Gate in the governed tool-execution node while LangGraph keeps planning, routing, checkpoints, and state.

Where Gate goes

In the node that actually executes the side-effecting tool.

Keep the platform's normal reasoning and orchestration. Gate only the exact action at the last safe point before execution.

Planner routes tool→Governed tool node checks Gate→Execute, interrupt, revise, or route back

Start here

1
Build the final action.
Let LangGraph choose the action and produce the arguments it intends to execute.
2
Check the exact action with Gate.
Send tool_name and the final payload immediately before the side effect.
3
Follow one of four outcomes.
Continue, wait, revise, or stop. You do not need the advanced features to get this basic path working.

Minimal setup

Graph state	Store
Proposed action	`tool_name` and final arguments
Review pause	`thread_id`
Requested change	Reviewer feedback and revised proposal

Handle the decision

Outcome	Gate status	What LangGraph should do
Continue	`allow` or `approved`	Execute the exact proposed action. If signed proof is required, validate it first.
Wait	`pending_review`	Store `thread_id` and resume that exact review later.
Revise	`changes_requested`	Return reviewer feedback to the part of the runtime that can revise the proposal.
Stop	`reject` or `rejected`	Do not execute. Replan, fall back, or end the action.

Unknown or failed decision = stop.

Fail closed if Gate cannot be reached, returns an unknown state, or required approval proof is missing or invalid.

Platform notes

Use LangGraph checkpoint/interrupt behavior for human-review pauses.
Route changes_requested back to planning or revision, not to execution.
Make the side-effect node reachable only after an executable Gate outcome.

Advanced: review threads, revisions, proof, and audit

task_id is your grouping ID. thread_id identifies the exact Gate review and should be persisted whenever work can pause.

For changes_requested, revise on the same review thread using the revision event contract. For high-impact actions that require signed proof, validate the returned approval token before execution. Log execution success or failure when you need complete audit evidence.

For long reviews, use the platform's durable continuation mechanism instead of keeping a process, workflow, or runner open.

Advanced runtime patterns Full Gate API Exact decision states