haystack_agentmesh 3.4.0

AgentMesh governance components for Haystack pipelines — policy enforcement, trust scoring, and tamper-evident audit trails

haystack-agentmesh

AgentMesh governance components for Haystack pipelines — policy enforcement, trust scoring, and tamper-evident audit trails.

Installation

pip install haystack-agentmesh

With Haystack:

pip install "haystack-agentmesh[haystack]"

Components

GovernancePolicyChecker

Enforces governance policies loaded from YAML files. Checks tool allowlists/blocklists, content patterns, token limits, and rate limits.

from haystack_agentmesh import GovernancePolicyChecker

checker = GovernancePolicyChecker(policy_path="policy.yaml")
result = checker.run(action="search", params={"query": "hello"}, agent_id="agent-1")
# {"decision": "allow", "reason": "All policy checks passed", "passed": True}

Policy YAML example:

allowed_tools:
  - search
  - summarize
blocked_tools:
  - delete_all
blocked_patterns:
  - pattern: "DROP TABLE"
    type: substring
  - pattern: "rm\\s+-rf"
    type: regex
max_tokens: 4096
rate_limit:
  max_calls: 10
  window_seconds: 60

TrustGate

Trust scoring with time-based decay and routing decisions.

from haystack_agentmesh import TrustGate

gate = TrustGate(pass_threshold=0.7, review_threshold=0.4)

gate.record_success("agent-1")
result = gate.run(agent_id="agent-1")
# {"trusted": False, "score": 0.55, "action": "review"}

Actions: pass (trusted), review (marginal), block (below threshold).

AuditLogger

Append-only audit log with SHA-256 hash chain hashing for tamper evidence.

from haystack_agentmesh import AuditLogger

logger = AuditLogger()
result = logger.run(action="search", agent_id="agent-1", decision="allow")
# {"entry_id": "a1b2c3d4e5f67890", "chain_hash": "sha256..."}

assert logger.verify_chain()  # Verify integrity
logger.export_jsonl("audit.jsonl")  # Export for analysis

Pipeline Example

from haystack import Pipeline
from haystack_agentmesh import GovernancePolicyChecker, TrustGate, AuditLogger

pipe = Pipeline()
pipe.add_component("trust_gate", TrustGate())
pipe.add_component("policy_checker", GovernancePolicyChecker(policy_path="policy.yaml"))
pipe.add_component("audit", AuditLogger())

Component Reference

Component	Inputs	Outputs
GovernancePolicyChecker	action: str, params: dict, agent_id: Optional[str]	decision: str, reason: str, passed: bool
TrustGate	agent_id: str, min_score: Optional[float]	trusted: bool, score: float, action: str
AuditLogger	action: str, agent_id: str, decision: str, metadata: Optional[dict]	entry_id: str, chain_hash: str

Development

pip install -e ".[dev]"
pytest tests/ -v

License

Apache-2.0