# Open-source AI customer service agents that stop before billing

> An open-source AI customer service agent is a running machine rather than a resolution price, and the difference shows on the ticket the knowledge base never answered. It reads the codebase and the billing account behind the complaint, then stops for a person before it changes either.

URL: https://aicustomerserviceagentguide.com/

Independent comparison · checked October 2026

**The open-source AI Operating System**

`kortix.yaml`

```yaml
policies:
  - match: gmail.send_email
    action: require_approval
    conditions:
      - arg: to
        match: "*@example.com"
```

Source: https://kortix.com/docs/project/manifest

Approval gates you set. Off until you set them.

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Open source · Self-host is free · Approval rules sit in the project manifest

## Five agents on the terms a support lead checks

Kortix is our recommendation. Prices are each vendor's own, opened 27 October 2026.

| | Kortix (our pick) (recommended) | Intercom Fin | Zendesk AI agents | Salesforce Agentforce | Lindy |
| --- | --- | --- | --- | --- | --- |
| Price model | Credits from $50 a month, at 100 credits per dollar. | $0.99 per outcome; $49 a month minimum for 50. | €19 to €115 per agent a month, plus €1.50 a resolution. | $500 per 100,000 credits; an action is 20. | $49.99 a month per active user for 5,000 credits. |
| Works with your helpdesk | Any helpdesk, through a connector; 3,000+ apps and MCP. | Any helpdesk, including Salesforce and Zendesk. | Its own helpdesk, priced per agent. | Service Cloud, with Sales and Service editions. | 1,500+ integrations plus MCP. |
| Where it runs | Kortix Cloud, your VPC, or your own on-prem network. | Intercom's cloud. | Zendesk's cloud. | Salesforce's cloud. | Lindy's cloud. |
| Where a person approves an action | Approval gates you set. Off until you set them. | A person takes over when the customer asks. | A human agent takes the ticket. | A service rep handles the escalation. | Approvals built in. |
| Reaches your codebase and billing | Scoped access to the knowledge, the codebase and Stripe. | API, MCP and data integrations. | Apps and APIs on Zendesk data. | Salesforce data and flows. | Computer use and 40+ built-in skills. |
| Open source | Yes | No | No | No | No |

Prices and plans come from each vendor's pricing page, opened 27 October 2026; Zendesk bills in euros. Capabilities are described from what each vendor publishes.

## Pick the agent that fits your helpdesk

Three questions, then the check to run before you sign.

1. Where does the answer have to come from? (Help center articles / The billing account / The codebase / Order records in our suite)
2. Who signs off a refund? (A person in the helpdesk / A rule in the config, before the call runs / The suite's approval flow)
3. Where must the agent run? (Wherever our helpdesk is / In one all-in-one helpdesk / In the suite our service team uses / In our own VPC or on-prem network)

Possible answers:

- **Fin on the helpdesk you keep**: Fin is $0.99 per outcome with a $49 minimum, and it works with any helpdesk, including Salesforce and Zendesk. Check your monthly conversation count, then ask what counts as an outcome.
- **A helpdesk-native agent**: Zendesk prices its plans per agent, from €19 to €115 a month, plus €1.50 for each automated resolution. Check how many agent seats you would still need once the agent takes the easy half.
- **A suite agent on the platform you already run**: Agentforce sells Flex Credits at $500 per 100,000, an action costs 20 credits and a voice action 30, and the add-on comes with Sales and Service editions from $550 a user. Work out your action volume first.
- **A self-hosted agent with a rule in front of every call**: Kortix is the route when the agent has to reach the billing account and the repo, and a rule has to stop it. A policy rule in `kortix.yaml` holds a call to Stripe or the repo until a person decides. Self-host when the agent has to run on your own network.

## Questions a support lead asks before signing

Short answers to the questions that decide the choice.

### Can an AI agent refund a customer on its own?

Yes, if the tool you connect lets it, which is why the approval rule matters more than the model. In Kortix a matching call is held for a person and runs only after that decision; approval holds default to 24 hours and `approvals.ttl` sets the limit.

### Do we have to replace our helpdesk?

No. Fin works with any helpdesk, including Salesforce and Zendesk, and Kortix connects to the helpdesk you already run instead of replacing it.

### Can Kortix run on our own infrastructure?

Yes. Run it on Kortix Cloud, in your VPC, or on your own on-prem network. Self-host is free.

### Can an agent work a real support queue today?

Yes. Kortix's own support inbox in Plain runs on an agent with scoped access to the product's knowledge, its codebase and Stripe; it investigates, resolves what it can, and stops at a person for sensitive actions.

### Does every message need a person to start it?

No. An event trigger on the support inbox, `gmail.message.received` in the example, starts a session when a message arrives, and the agent triages the thread from there.

## Put the approval rule in the repo, then let the agent work the queue.

Start with one support inbox and one rule that stops before money moves.

[Try Kortix](https://kortix.com) · [Take the three questions](https://aicustomerserviceagentguide.com/#fits)