# BodulskiHal: Hallucination Guard for AI Agents (MCP) (`bodul/bodulskihal-claim-verifier`) Actor

Verify AI-agent claims against supplied structured evidence over MCP. Get FACT, INFERENCE, ESTIMATE, UNKNOWN, REFUTED or CONFLICT, an APPROVE/BLOCK/ESCALATE verdict and a SHA-256 receipt. Your application enforces the decision.

- **URL**: https://apify.com/bodul/bodulskihal-claim-verifier.md
- **Developed by:** [Damir](https://apify.com/bodul) (community)
- **Categories:** AI, Developer tools, MCP servers
- **Stats:** 1 total users, 0 monthly users, 0.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $10.00 / 1,000 verified claims

This Actor is paid per event and usage. You are charged both the fixed price for specific events and for Apify platform usage.

Learn more: https://docs.apify.com/actors/running/actors-in-store.md#pay-per-event

## What's an Apify Actor?

An Actor is a serverless cloud program that runs on the Apify platform. It has two run modes.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.

Apify vocabulary and the platform model are defined once, in the agent quickstart at https://apify.com/agents.md.

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.

Do not guess an integration path. Every one of them is in the agent quickstart at https://apify.com/agents.md: the Apify MCP server, Agent Skills with the Apify CLI, the JavaScript and Python clients, the REST API, and the account-free path for an agent with no human to sign in. It also carries the rule on stating cost before the first paid run.

For examples already wired to this Actor's own input schema, see the [API](#api) section below.

Each client library has reference documentation the quickstart does not restate: [JavaScript/TypeScript](https://docs.apify.com/api/client/js/docs.md) (`npm install apify-client`) and [Python](https://docs.apify.com/api/client/python/docs.md) (`pip install apify-client`).

# README

## BodulskiHal: Evidence-Based Claim Verification for AI Agents

**Check the evidence before your agent says “done”.**

BodulskiHal is a deterministic MCP server that evaluates structured claims against the evidence you provide. It returns a classification, a decision, a reason and a SHA-256 receipt so your agent can decide whether to proceed, gather more evidence or ask for human review.

Use it to check observations, completion claims and evidence-sensitive agent responses. The verifier contains no LLM. Your application must call the tool and enforce its decision.

### Connect your MCP client

This Actor serves **Streamable HTTP** through Apify Standby mode:

```text
https://bodul--bodulskihal-claim-verifier.apify.actor/mcp
```

Supply your Apify API token in the HTTP header:

```text
Authorization: Bearer <YOUR_APIFY_TOKEN>
```

For clients that support this configuration format:

```json
{
  "mcpServers": {
    "bodulskihal": {
      "url": "https://bodul--bodulskihal-claim-verifier.apify.actor/mcp",
      "headers": {
        "Authorization": "Bearer <YOUR_APIFY_TOKEN>"
      }
    }
  }
}
```

Client configuration varies. Choose a remote MCP connection with Streamable HTTP and custom header support. Keep your real token in your client's secret settings.

#### Standby mode and the Start button

Connect through the MCP URL above. A normal **Start** run launches a long-running HTTP server; it does not perform a verification or produce dataset rows on its own. Such a run can end with **Timed out** when its configured run limit is reached. Use the **Server** tab for the Standby endpoint and connection details.

### Available tools

| Tool | Input | Result |
| --- | --- | --- |
| `verify_claim` | One `payload` with `claim`, `evidence`, `policy` and `evaluation_time`; optional `human_approved` | One classification, verdict, reason and receipt for valid input |
| `verify_claims` | One `payload` with `claims`, `evidence_by_claim`, `policy` and `evaluation_time`; optional `human_approvals` | Per-claim results and an overall verdict |

Send structured evidence, not just a question or a URL. See **JSON_CONTRACT.md** in the Source tab for the full schema, allowed values and batch format.

### Try a single claim

Call `verify_claim` with these MCP tool arguments:

```json
{
  "payload": {
    "claim": {
      "id": "count-1",
      "text": "Conversation has 30 questions",
      "type": "observation",
      "risk": "low"
    },
    "evidence": [],
    "policy": {
      "version": "3.0",
      "max_age_seconds": 300
    },
    "evaluation_time": "2026-11-03T12:00:00+00:00"
  }
}
```

With no evidence, the expected result includes:

```json
{
  "classification": "UNKNOWN",
  "verdict": "BLOCK",
  "reason": "insufficient_eligible_evidence"
}
```

This is an excerpt; valid requests also return a receipt. For a live workflow, set `evaluation_time` to the current evaluation time and provide actual evidence with its original observation timestamp. A recent supporting observation still needs to pass the applicable policy gates before approval.

### Read the result

Classification describes the evidence assessment. **Verdict is the decision your application should enforce.**

| Classification | Meaning |
| --- | --- |
| `FACT` | Direct eligible support; approval still depends on the remaining gates |
| `INFERENCE` | Derived or indirect support; blocked from being presented as a verified fact |
| `ESTIMATE` | Approximate claim; blocked from being presented as a verified fact |
| `UNKNOWN` | Insufficient eligible or authorized evidence |
| `REFUTED` | Eligible evidence contradicts the claim |
| `CONFLICT` | Contradictory input or conflicting eligible evidence; blocked |

| Verdict | What your agent should do |
| --- | --- |
| `APPROVE` | Proceed within the evaluated claim and policy scope |
| `BLOCK` | Stop the claim or dependent action and address the returned reason |
| `ESCALATE` | Obtain the required clarification, independent evidence or human approval |

Evidence freshness follows `max_age_seconds`. Future evidence is rejected by default. Action-completion claims require direct post-action evidence under the default policy. Medium-risk claims require two independent sources by default; high-risk claims require human approval.

### Billing

The wrapper charges one `claim-verified` event per evaluated claim. Batch calls charge per claim, not per request. A valid evaluation is billable even when its verdict is `BLOCK` or `ESCALATE`. Invalid input rejected by the verifier wrapper is not charged a claim-verification event.

See the **Pricing** tab for current rates and applicable platform costs.

### Limits and receipts

BodulskiHal evaluates the evidence you submit. It does not browse sources, authenticate external evidence or establish real-world truth independently. A SHA-256 receipt supports integrity checking; it is not proof that the submitted evidence is true.

The MCP transport is stateless. The tool wrapper does not explicitly persist claim payloads; this is not a guarantee about platform logging or retention. Review your hosting and client settings before sending sensitive data.

For schema details, open **JSON_CONTRACT.md** in Source. For questions or custom policies, open an issue on this Actor.

# Actor input Schema

## Actor input object example

```json
{}
```

# Actor output Schema

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {};

// Run the Actor and wait for it to finish
const run = await client.actor("bodul/bodulskihal-claim-verifier").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = {}

# Run the Actor and wait for it to finish
run = client.actor("bodul/bodulskihal-claim-verifier").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print(f"💾 Check your data here: https://console.apify.com/storage/datasets/{run.default_dataset_id}")
for item in client.dataset(run.default_dataset_id).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{}' |
apify call bodul/bodulskihal-claim-verifier --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,bodul/bodulskihal-claim-verifier"
        }
    }
}
```

The hosted server signs you in with OAuth on first connect, so no API token belongs in this config. Clients without OAuth support can send an `Authorization: Bearer <APIFY_API_TOKEN>` header instead, using a token from API & Integrations in Apify Console (https://console.apify.com/settings/integrations).

## OpenAPI specification

Download the OpenAPI definition: https://api.apify.com/v2/actors/mfPRULEiOAklvgOe9/builds/BOg2LRa552CNh36b6/openapi.json