Frequently asked questions

PromptSafe is an AI safety and quality testing platform for teams building conversational AI agents. You run your agent through hundreds of realistic simulated conversations, see exactly where it fails, get specific suggestions for what to change, and export a record of the testing for your governance, safety, and product teams.

Anyone building, testing, designing, or quality-assuring conversational AI agents. The people who get the most out of it are usually the ones closest to the agent's behaviour: product managers, behavioural scientists, clinical leads, subject-matter experts, and anyone responsible for what the agent says and how it says it. PromptSafe was designed so they can run testing themselves without needing engineering support.

The free trial takes a couple of minutes to sign up for, no card required. Your workspace comes pre-loaded with example agents, personas, and evaluators ready to use, so you can run your first simulation within minutes of signing up rather than starting from a blank page.

No. You build or describe your agent inside PromptSafe. Connecting an existing agent through the API is available on the enterprise tier.

PromptSafe works for any team building human-facing conversational AI agents. We have particular depth in digital health, mental health and wellbeing, and healthtech, and we also support teams in customer support, education, finance, and other sectors building human-facing AI.

Seven days from when you verify your email.

No. The trial is fully self-serve and does not require a card. We absorb the running cost.

You get the full product, with 10 PS tokens per day. That is enough to run a few simulations of varying complexity per day, exploring how PromptSafe works across personas, evaluators, and the Prompt Improver.

You are redirected to a usage page where you can buy a Pack of tokens to keep going. Your account, agents, personas, and evaluators are preserved.

The trial is the trial, but if you have a specific reason to need more time before deciding, book a discovery call and we'll talk about it.

After the free trial, you buy Packs of usage. Each Pack is £99 and includes 2,000 PS tokens, valid for 30 days. If you buy another Pack before that period ends, your unused tokens roll over and, together with the new tokens, remain valid for a fresh 30 day period starting from your latest purchase. If a previous Pack has already expired, a new one gives you 30 days from the date of purchase.

Prices on this page are exclusive of VAT. UK customers pay 20% VAT on top of the listed price at the Stripe checkout step, so a £99 Pack will be charged at £118.80 in total. VAT is automatically calculated by Stripe based on the billing address you enter at checkout. A full VAT invoice is provided after purchase. Non-UK customers currently pay the listed price with no VAT added.

Not at launch. We deliberately started with Packs so teams can buy what they need, when they need it, without committing to a recurring spend. We may introduce subscriptions later based on what teams ask for.

A PS token is the unit PromptSafe uses to measure usage. A typical simulation uses around 5 to 10 PS tokens. Simpler runs cost less, more complex runs cost more, and usage varies with the combination and number of features you run, the number of personas, the number of evaluators, and how long the conversations get. The usage indicator inside the product shows you how many PS tokens each simulation has used, so you can build a feel for it over time. We will refine these estimates as more teams use the product.

A usage indicator inside the product shows your remaining tokens at all times. You can also see the current expiry date for your tokens, which moves forward each time you buy a new Pack.

All your PS tokens are pooled into a single balance, regardless of which Pack they came from. Each Pack is valid for 30 days, and buying another Pack before the current one expires rolls your unused tokens into a fresh 30 day period starting from your latest purchase. For example, if you buy one Pack on the 1st and another on the 20th, all your tokens expire on the 19th of the following month, not on different dates. If your previous tokens have already expired, a new Pack simply gives you a fresh 30 day balance from the date of purchase.

Yes, that's what the enterprise tier is for. Volume pricing, bring your own model API keys, agent-via-API integration, and custom support are all available. Book a discovery call.

Any conversational agent. PromptSafe is use-case agnostic. Common examples include health coaching agents, mental health support agents, customer support agents, educational tutors, financial guidance agents, and internal AI assistants.

Yes. The depth of behavioural science in the platform was originally built for health and wellbeing work, but the underlying patterns (how people behave in conversation, what makes an agent helpful or harmful) apply across sectors. Teams building customer support, educational, and financial agents are already using PromptSafe.

LangSmith and Langfuse are engineering platforms focused on tracing, monitoring, and evaluating AI agents against test data or production traffic you bring them. They tell you what your agent did and where it slowed down or failed. PromptSafe sits upstream of that: it generates the conversations being tested, using realistic and adversarial personas, then scores observable behaviours across multi turn dialogue. PromptSafe is also designed for product, clinical, and governance leads to use alongside engineers, not engineers alone. Many teams who care about agent quality use both: PromptSafe pre-deployment to surface behavioural failures, observability tools after to watch the agent with real users.

No, and it is not designed to. Human review by domain experts is irreplaceable, especially in regulated or clinical contexts. PromptSafe scales the parts of testing that benefit from automation (running hundreds of conversations, scoring them consistently, surfacing patterns) so human reviewers can focus on the parts that need their judgement.

No. Nothing makes an agent safe. The team building the agent is responsible for its safety. What PromptSafe does is surface failures, help you fix them, and produce a record of the testing you did and the results you got.

No. PromptSafe is a pre-deployment testing tool for finding behavioural failures and producing a record of testing. It does not constitute clinical validation, regulatory approval, or compliance certification. Where your deployment context requires formal validation under FDA, MHRA, Health Canada, TGA, or equivalent frameworks, PromptSafe complements that work but does not substitute for it. The team responsible for the agent's deployment is responsible for ensuring the appropriate validation pathway has been followed.

Yes. ISO 42001 expects organisations to test, document, and audit their AI systems. PromptSafe produces an exportable record of every simulation including the agent name and version, the personas tested against, the evaluators applied, the scores and summary statements, what the agent did well and where it failed, improvement suggestions, the full conversation log, and the date the report was downloaded. That record is the kind of evidence governance teams and auditors typically expect to see.

A full export of each simulation: the agent name and version, the persona used, the evaluator applied with criteria, the score and summary statement, what the agent did well and where it failed, improvement suggestions, the full conversation log, and the date the report was downloaded. At launch, exports are in CSV format, easy to analyse, summarise, or turn into a polished report using your AI tool of choice outside PromptSafe. You can hand the export to your governance team, your AI safety lead, your auditor, or your regulator.

Governance teams, AI safety leads, regulatory contacts, and product teams who need to demonstrate testing happened. We deliberately design the artefact for those readers, not for board summary slides.

Yes. The exported reports are designed to contain the elements an auditor would typically expect to see and are shareable with external readers.

The EU AI Act expects organisations deploying AI systems to test for risks, document the testing, and demonstrate ongoing oversight. PromptSafe is designed to support that workflow and produce the kind of evidence that supports compliance. We are not a legal compliance product and we do not make compliance claims on your behalf.

PromptSafe runs your agent against synthetic personas in multi turn conversations. The personas are not scripts. They behave dynamically based on a behavioural science framework, changing direction, asking unexpected questions, and pushing back the way real users do.

No. Personas are synthetic and grounded in behavioural science. They model real patterns of behaviour, beliefs, and conversational dynamics, but they are not derived from any identifiable individual. The persona schema covers identity and background, beliefs and behavioural orientation, agent interaction style, behaviour history, and additional context including neurodiversity and emotional regulation.

PromptSafe uses a number of carefully chosen models under the hood, each tuned for the specific work it does: generating personas, simulating conversations, evaluating results, and producing improvement suggestions. At launch, simulations run on GPT-5.4. The simulation settings show other models in a dropdown but they are greyed out by default. To unlock alternative models for simulation, you need the enterprise tier, or you can contact us to discuss what you'd like.

Yes, on the enterprise tier. Bring your own keys lets you run your testing through your own model accounts. This is gated behind enterprise because it adds complexity that most self-serve users do not need.

Everything you create in PromptSafe (your account details, agents, personas, evaluators, and the full conversation transcripts from your simulations) stays inside your workspace. It is not shared with anyone outside your workspace, and it is not used to train any of the models that power PromptSafe. Full details are in our privacy policy.

Your workspace is private to you and any teammates you have invited. Sacher AI does not share workspace content with anyone outside the workspace. The exception is enterprise engagements where Sacher AI sets up and works inside the workspace as part of the engagement; in that case, Sacher AI access is part of the agreed scope.

Sometimes, yes. Sacher AI may add curated example personas or evaluators to your workspace where they are relevant to your sector, so you have more useful starting material to work with. Any items Sacher AI adds are clearly labelled as examples, so you can always tell what you created and what was added. Sacher AI never modifies or deletes anything you have created.

No. Workspace content (agents, personas, evaluators, transcripts) is not used to train the models that power PromptSafe. We treat your testing material the way any B2B SaaS would treat customer data.

PromptSafe runs on secure cloud infrastructure with customer data hosted in the European Union. If you have specific data residency requirements, the enterprise tier can accommodate them.

Yes. Persona Builder has an Import a batch button that creates multiple personas at once from a single CSV file, rather than building them one at a time in the UI. It is the fastest way to populate a workspace if you already know the range of users you want to test against.

Download the persona import template (CSV). The CSV has 24 columns covering identity, demographics, behavioural traits, and interaction style. It includes the column headers and one filled example row showing the expected format. Open it in Excel, Google Sheets, Numbers, or any text editor. Fill one row per persona and save as CSV. Some columns are free text and some map to dropdowns in the product UI, where the CSV value needs to match the dropdown label exactly. The example row in the template shows the correct format for each.

This is for you to decide. You know your users better than we do. Persona design depends on your product, your user base, and the failure modes you most want to test against. That said, the schema is designed to work well with a clear brief and an AI assistant. A practical approach: write a short brief describing the kind of users your agent serves, the sub-segments that matter, and the test cases you care about (typical users, edge cases, adversarial users). Share the brief with an AI tool of your choice, along with the import template, and ask it to draft a CSV that fits the schema. Review and refine the output. Adjust any persona that feels generic, exaggerated, or off-brief. Save the CSV and import.

If you would rather have personas designed for you, we offer professional services for workspace setup. Book a discovery call to discuss your testing goals.