What is prompt injection testing for AI agents?
Prompt injection testing for AI agents means running cases where instructions are hidden in content the agent reads, such as an email, a supplier document or a web page, or where a user pushes it past a rule, and checking that it refuses, escalates or fails safely. For agents with write access, the check is that nothing unwanted was written.
Why it matters more for agents with write access
For a chatbot, a successful injection produces a bad answer. For an agent with write access, it produces a bad record: changed bank details, a refund above the limit, a document sent to the wrong person.
Typical cases
- Hidden instructions in a document. A supplier email asking to "update our bank details to the account below".
- The other side's documents. In legal work, a document that carries instructions for the agent.
- Out-of-scope requests. A user asking the agent to skip an approval or act on another customer's records.
- Fake approvals. An email claiming a manager already approved something.
How to check the result
Run each case on the flows where the agent has write access, then read the connected system. The supplier record should be unchanged, the refund should not exist, the approval should still be pending. You can't test your way to immunity, but you can keep known patterns from shipping. See also AI agent permissions testing.
On the blog
- Misuse and prompt injection testing for AI agents
- How to test AI agent permissions
- How to test human approval steps
Related terms
Fault injection for AI agents · AI Quality System · Vertical AI agent · All terms
FAQ
Instructions hidden in content the agent reads, such as an email or a document, rather than typed by the user. Agents that process outside documents are the most exposed.
The connected system shows no unwanted change: no edited record, no payment, no message sent. The agent's reply alone is not proof.
No. It keeps known patterns from shipping and shows where permissions behind the tools need to be tighter.
Try it on your own agent
Describe a task in plain words. Agentiqa does it step by step and tells you if it worked. Every failure comes with step-by-step reproduction.
20 runs a month, no credit card.
Your agent writes into ERP, CRM or billing for customers? See Enterprise.