Enterprise Inference Hooks: Real-Time DLP Before Every Claude Prompt
Anthropic has shipped inference hooks in beta for all Claude Enterprise organisations — a vendor-agnostic inspection layer that intercepts every governed prompt before the model sees it. The organisation's AI security or DLP server receives the full conversation transcript via a signed HTTPS POST, returns an allow or deny verdict within 5 seconds, and Claude either proceeds or halts. Denied prompts never reach the model.
How it works
When inference hooks are configured, every covered request follows this path:
- Claude receives the user's message but pauses before inference.
- Anthropic sends a
POSTto the organisation's configured endpoint with the transcript, signed using the Standard Webhooks spec (webhook-id/webhook-timestamp/webhook-signatureheaders, HMAC-SHA256). - The AI security server inspects the content and returns a compact JSON verdict.
- Claude either generates a response (allow) or returns a denial message (deny).
# Allow verdict
{ "action": "allow" }
# Deny verdict — deny_reason shown to user; reference_id logged
{
"action": "deny",
"deny_reason": "This request contains regulated financial data. Please remove account numbers before continuing.",
"reference_id": "dlp-event-20260809-00421"
}
Scope and limits
- Covered surfaces: claude.ai chat, Claude Cowork, and Claude Code sessions for Enterprise orgs.
- Not covered: Amazon Bedrock or Google Cloud deployments; voice mode; system prompts; raw file bytes and images (text content of attachments is included).
- Timeout: 5,000 ms default (configurable 1–10,000 ms); one automatic retry after 100 ms on connection failure only.
- Failure mode: configurable as "block the request" (fail-closed) or "allow the request" (fail-open).
- Source IPs:
160.79.106.0/24;User-Agent: anthropic-dlp/1. - Request schema fields:
type(always"prompt"today),request_id,tenant_id,actor(user id + email),source.application(claude-aiorclaude-code),messages,session_id,model.
Rollout controls
Inference hooks ship with three safeguards designed for phased enterprise deployments:
- Shadow mode: hooks receive the request and return verdicts, but Claude ignores denials — lets you measure false-positive rates before enforcement goes live.
- Rollout percentage: inspect 0–100% of requests, so you can start with a small traffic slice and increase gradually.
- Role-based exclusions: custom roles (e.g. IT admins, security analysts) can be exempted from inspection.
- Circuit breaker: sustained hook failures automatically stop enforcement; an admin must manually re-enable. Every denial is recorded in the Compliance Activity Feed.
The inference hooks endpoint is fully vendor-agnostic: any organisation can implement the HTTPS endpoint themselves or use a security vendor that supports the Standard Webhooks spec. The system prompt, file bytes, and images are never sent to your hook server, so your DLP logic sees only the text conversation — the same transcript a human reviewer would read. Start with shadow mode on 5–10% of traffic, tune your rules, then raise rollout percentage and switch to enforcement.