# POLICY_VIOLATION

URL: https://tailrace.dev/docs/reference/errors/POLICY_VIOLATION

> A block policy matched - the sensitive value must not cross the boundary.



## What it means [#what-it-means]

`PolicyViolationError` (`code: POLICY_VIOLATION`). Policy resolved to `block` for one or more spans. Integrations translate this into their host failure mode (throw, JSON-RPC error, HTTP 422, Claude Code deny).

## Message shape [#message-shape]

```text
policy blocked entity "<entity>" via rule "<rule>" → https://tailrace.dev/docs/reference/errors/POLICY_VIOLATION
```

`decisions` on the error lists each blocked span (entity, boundary, rule, contentHash) - never the raw value.

## Common causes [#common-causes]

1. Default policy (or yours) blocks secret classes (`api_key`, `jwt`, …) at this boundary.
2. Prompt, tool args, or MCP payload still contains a live secret.
3. Streaming `abort` mode hit a complete secret span mid-stream.

## Fixes [#fixes]

1. Remove the secret from the payload, or tokenize upstream and send the token.
2. If you intentionally need the value at a trusted egress, use `tailrace.restore` only at `{ kind: "egress", sink }` - never at model/tool/mcp.
3. Relaxing a secret to `allow` requires `dangerouslyAllowSecrets: true` on the rule (and is almost never correct).

## Safe to catch? [#safe-to-catch]

Yes at integration boundaries - map to the host error. Do not log `decisions` values that might have been attached elsewhere; hashes and entity classes only.