> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kosli.com/llms.txt
> Use this file to discover all available pages before exploring further.

<AgentInstructions>

## Submitting Feedback

If you encounter incorrect, outdated, or confusing documentation on this page, submit feedback:

POST https://docs.kosli.com/feedback

```json
{
  "path": "/client_reference/kosli_evaluate_trail",
  "feedback": "Description of the issue"
}
```

Only submit feedback when you have something specific and actionable to report.

</AgentInstructions>

# kosli evaluate trail

> [BETA] Evaluate a trail against a policy.

## Synopsis

```shell theme={"theme":"dracula","languages":{"custom":["/languages/rego.json"]}}
kosli evaluate trail TRAIL-NAME [flags]
```

\[BETA] Evaluate a trail against a policy.
Fetch a single trail from Kosli and evaluate it against a Rego policy.
The trail data is passed to the policy as `input.trail`.

Use `--attestations` to enrich the input with detailed attestation data
(e.g. pull request approvers, scan results). Use `--show-input` to inspect the
full data structure available to the policy. Use `--output json` for structured output.

## Flags

| Flag                   | Description                                                                                                                                       |
| :--------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------ |
| --assert               | \[optional] Exit with a non-zero status when the policy denies. This is the current default; pass --assert to lock it in across future releases.  |
| --attestations strings | \[optional] Limit which attestations are included. Plain name for trail-level, dot-qualified (artifact.name) for artifact-level.                  |
| -f, --flow string      | The Kosli flow name.                                                                                                                              |
| -h, --help             | help for trail                                                                                                                                    |
| --no-assert            | \[optional] Print the result and always exit 0, even when the policy denies. Use when this command feeds another tool as a policy decision point. |
| -o, --output string    | \[defaulted] The format of the output. Valid formats are: \[table, json]. (default "table")                                                       |
| --params string        | \[optional] Policy parameters as inline JSON or @file.json. Available in policies as data.params.                                                 |
| -p, --policy string    | Path to a Rego policy file to evaluate against the trail.                                                                                         |
| --show-input           | \[optional] Include the policy input data in the output.                                                                                          |

## Flags inherited from parent commands

| Flag                      | Description                                                                                                 |
| :------------------------ | :---------------------------------------------------------------------------------------------------------- |
| -a, --api-token string    | The Kosli API token.                                                                                        |
| -c, --config-file string  | \[optional] The Kosli config file path. (default "kosli")                                                   |
| --debug                   | \[optional] Print debug logs to stdout. A boolean flag [docs](/faq/#boolean-flags) (default false)          |
| -H, --host string         | \[defaulted] The Kosli endpoint. (default "[https://app.kosli.com](https://app.kosli.com)")                 |
| --http-proxy string       | \[optional] The HTTP proxy URL including protocol and port number. e.g. `http://proxy-server-ip:proxy-port` |
| -r, --max-api-retries int | \[defaulted] How many times should API calls be retried when the API host is not reachable. (default 3)     |
| --org string              | The Kosli organization.                                                                                     |

## Live Examples in different CI systems

<Tabs>
  <Tab title="GitHub">
    View an example of the `kosli evaluate trail` command in GitHub.

    In [this YAML file](https://github.com/cyber-dojo/snyk-scanning/blob/9508524934b5a7a42caedb42f6675d177f841568/.github/workflows/artifact_snyk_test.yml#L350)
  </Tab>
</Tabs>

## Examples Use Cases

These examples all assume that the flags  `--api-token`, `--org`, `--host`, (and `--flow`, `--trail` when required), are [set/provided](/getting_started/install/#assigning-flags-via-environment-variables).

<AccordionGroup>
  <Accordion title="evaluate a trail against a policy">
    ```shell theme={"theme":"dracula","languages":{"custom":["/languages/rego.json"]}}
    kosli evaluate trail yourTrailName
    	--policy yourPolicyFile.rego

    ```
  </Accordion>

  <Accordion title="evaluate a trail with attestation enrichment">
    ```shell theme={"theme":"dracula","languages":{"custom":["/languages/rego.json"]}}
    kosli evaluate trail yourTrailName
    	--policy yourPolicyFile.rego
    	--attestations pull-request

    ```
  </Accordion>

  <Accordion title="evaluate a trail and show the policy input data">
    ```shell theme={"theme":"dracula","languages":{"custom":["/languages/rego.json"]}}
    kosli evaluate trail yourTrailName
    	--policy yourPolicyFile.rego
    	--show-input
    	--output json

    ```
  </Accordion>

  <Accordion title="evaluate a trail with policy parameters (inline JSON)">
    ```shell theme={"theme":"dracula","languages":{"custom":["/languages/rego.json"]}}
    kosli evaluate trail yourTrailName
    	--policy yourPolicyFile.rego
    	--params '{"min_approvers": 2}'

    ```
  </Accordion>

  <Accordion title="evaluate a trail with policy parameters from a file">
    ```shell theme={"theme":"dracula","languages":{"custom":["/languages/rego.json"]}}
    kosli evaluate trail yourTrailName
    	--policy yourPolicyFile.rego
    	--params @params.json

    ```
  </Accordion>

  <Accordion title="evaluate a trail as a decision point (print verdict, never fail the step)">
    ```shell theme={"theme":"dracula","languages":{"custom":["/languages/rego.json"]}}
    kosli evaluate trail yourTrailName
    	--policy yourPolicyFile.rego
    	--no-assert
    ```
  </Accordion>
</AccordionGroup>