gate-sdk

Developer SDK for Gatekeeper — tool access control for AI agents.

GateClient is the thing you import. Register tools with execution classes, set a mode (or wire a signal source), call filter() before every agent turn, and the visible manifest shrinks as threat rises. Ships adapters for OpenAI and Anthropic tool formats.

Install

pip install gate-sdk  # once published
# or from source:
pip install -e .[dev]

# framework extras:
pip install gate-sdk[openai]
pip install gate-sdk[anthropic]

Quick example

from gate_sdk import GateClient

client = GateClient(mode=0.0)
client.add_tool("read_file", "read_only")
client.add_tool("deploy",    "high_impact")

result = client.filter()
# mode 0.0 -> both visible

client.mode = 0.85
result = client.filter()
# -> visible=['read_file'], suppressed=['deploy']

Framework adapters

from gate_sdk.adapters.openai import from_openai_tools, to_openai_tools

gate_tools = from_openai_tools(openai_schema, class_map={"deploy": "high_impact"})
client = GateClient(mode=current_threat_level)
client.add_tools(gate_tools)
safe_openai_tools = to_openai_tools(client.filter().visible)

Anthropic adapter mirrors the same API (from_anthropic_tools / to_anthropic_tools).

Mode sources

Pull mode from env, files, callables, or custom signals:

from gate_sdk.signals import StaticSignal, EnvSignal

client = GateClient(mode_source=EnvSignal("GATE_MODE"))
# GATE_MODE=0.8 python agent.py

Middleware and callbacks

client.use(lambda mode, result: log_filter(mode, result) or result)
client.on_suppress(lambda tool, mode: alert(f"{tool.name} suppressed at {mode}"))
client.on_mode_change(lambda old, new: audit_mode_change(old, new))

Envelope signing

env = client.authorize("read_file", signing_key="hmac-key", context_id="sess1")
# env.signature is HMAC-SHA256 over canonical form
assert client.verify(env, "hmac-key")

authorize() raises ValueError on suppressed tools — you can't sign what the gate has hidden.

Export back to framework tools

client.export_openai()     # only visible tools, ready for client.chat.completions
client.export_anthropic()  # only visible tools, ready for messages.create

Tests

pytest tests/

48 tests across client, adapters, signals, middleware, envelope flows, and failure injection.

How it fits

Layer 1 (transport) in Gatekeeper. Depends on gate-keeper (Layer 0). Feeds gate-policy (Layer 2) and gate-compliance (Layer 2) via middleware hooks.

License

Apache-2.0.