dbl-gateway 0.6.0

DBL Gateway

dbl-gateway

Deterministic execution boundary for LLM calls.

Accepts declared intents, applies policy, executes permitted calls, and records everything as an append-only event stream.

Part of the Deterministic Boundary Layer architecture.

Model

Every request passes through three surfaces:

Intent  ->  Decision  ->  Execution

Intent accepts and validates the request. Decision evaluates policy and produces a normative verdict (ALLOW / DENY). Execution calls the provider and enforces tool and budget constraints.

Each surface emits one event. Events are append-only, linked by correlation_id, and digested with SHA-256 over canonical JSON.

Only DECISION events are normative. Execution output never feeds back into policy.

Example

POST /ingress/intent
{
  "interface_version": 3,
  "correlation_id": "c-1",
  "payload": {
    "stream_id": "default",
    "lane": "user",
    "actor": "[e-mail]",
    "intent_type": "chat.message",
    "thread_id": "t-1",
    "turn_id": "turn-1",
    "parent_turn_id": null,
    "payload": {
      "message": "hello",
      "thread_id": "t-1",
      "turn_id": "turn-1",
      "declared_tools": ["web.search"],
      "tool_scope": "strict",
      "budget": { "max_tokens": 1024 }
    }
  }
}

The gateway produces three events:

INTENT     what was asked
DECISION   what was allowed  (permitted_tools, enforced_budget)
EXECUTION  what happened     (model output, tool_calls, tool_blocked)

Read them back:

GET /tail?stream_id=default&since=0

Install

pip install dbl-gateway

Or from source:

pip install -e .

Run

export DBL_GATEWAY_DB=./data/trail.sqlite
export DBL_GATEWAY_POLICY_MODULE=dbl_policy.allow_all
export DBL_GATEWAY_POLICY_OBJECT=policy
export OPENAI_API_KEY=sk-...

dbl-gateway serve --host 127.0.0.1 --port 8010

Providers

OpenAI, Anthropic, and Ollama. Configured via environment variables, exposed through GET /capabilities.

What This Is Not

• Not a RAG pipeline.
• Not a workflow engine.
• Not a chat UI.

The gateway does not decide what to do. It decides whether a declared action may execute.

Documentation

Document	Content
ARCHITECTURE.md	Three-surface model, component ownership, invariants
QUICKSTART.md	Setup, first request, reading events
wire_contract.md	Envelope format, tool gating, budget, refs
env_contract.md	All environment variables
CAPABILITIES.md	Runtime capability introspection
INVARIANTS.md	Machine-checkable invariant list
CONTEXT.md	Context resolution and ref classification
HOOKS.md	Pre-commit boundary enforcement
VALIDATION.md	Validation workflow
CHANGELOG.md	Version history

Related Repositories

• deterministic-boundary-layer -- specification and theory
• dbl-observer -- timeline and audit UI
• dbl-chat-client -- event-projection chat UI
• dbl-stack -- one-command full-stack setup

Status

v0.6.0. Core execution, policy gating, tool enforcement, and budget constraints are stable. Wire contract v3.