03Comparison
Agent execution boundary vs observability, guardrails and IAM
They answer different questions. Observability asks what the agent did. Guardrails ask what the model may say or take in. IAM asks who or what may access a system. An agent execution boundary asks whether this exact action was cleared before it ran, and keeps a record the agent did not write.
Most teams need more than 1 of them. None replaces the others.
The 4 questions side by side
| Observability | Guardrails | Identity and access (IAM) | Agent execution boundary | |
|---|---|---|---|---|
| Question it answers | What happened inside and around the agent? | What may the model take in or say? | Who or what may access this system? | Was this exact action cleared before it ran, and did the result land? |
| Who typically writes the record | The agent or its tools: traces and logs | The filter that sits on model input and output | The identity and permission system | The boundary, in a record the agent does not write |
| When it acts | Mostly after the fact | While the model generates | At access time | Before the action, with a check afterwards |
| What it cannot tell you | That the action was cleared, or that the receiving system agrees | That a specific action was cleared against a specific target | Whether the content of each action was right, or whether the result landed | Signatures prove and detect. They do not prevent. It covers only paths routed through it |
How they work together
Observability tells you the story. Guardrails shape what goes in and out of the model. IAM decides who gets through the door. A boundary sits at the point where a decision becomes an action, and leaves a record the agent did not write.
TrustGate does not replace your logs, your guardrails or your identity system. It adds the thing they do not give you: evidence that this action was cleared, written by something other than the agent.
A 3-question test for your own setup
- If an agent moved money tomorrow, which record would you show your auditor?
- Who wrote that record?
- If the receiving system disagreed, which record would you believe?
If the answer to the second question is the agent or its own tools, you have a story, not evidence.
What this page is not
It is not a ranking of products or a claim that any category is wrong. Each of the 4 is useful. It is a map of which question each answers.
Quick answers
What is the difference between observability and an agent execution boundary?
Observability records what happened, mostly after the fact, usually from the agent's own telemetry. An agent execution boundary returns a signed answer before the action runs and keeps a record the agent did not write.
Are AI guardrails the same as an agent execution boundary?
No. Guardrails shape what a model takes in or says. A boundary decides whether a specific action was cleared before it ran.
Does IAM cover AI agents?
IAM decides who or what may access a system. It does not judge the content of each action an agent takes or check that the result landed.