agenticrail 0.2.1

AgenticRail SDK — deterministic sequence enforcement for AI agents

agenticrail

AgenticRail Python SDK — deterministic sequence enforcement for AI agents.

Gate every step of your agent workflow before it executes. Cryptographic receipts. Zero enforcement failures.

pip install agenticrail

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What it does

AgenticRail sits beneath your agent and enforces that steps run in the right order, with no skips, no replays, and no re-entry after a sequence is sealed. Every decision — ALLOW, DENY, or HALT — produces a cryptographically signed receipt stored at the edge.

Three verdicts:

• ALLOW — step is clear, your agent code executes
• DENY — enforcement violation (wrong order, replay, sealed), execution blocked
• HALT — hard stop (injection attempt, poison payload detected), execution blocked

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Install

# Core client only
pip install agenticrail

# With LangGraph support
pip install "agenticrail[langgraph]"

# With CrewAI support
pip install "agenticrail[crewai]"

# Everything
pip install "agenticrail[all]"

---

Quick start — any framework

from agenticrail import RailClient

client = RailClient(api_key="DEMO-AGENTICRAIL-PUBLIC-2026")

# RailSequence sends step_order on every call — the gate reads it from each payload
seq = client.sequence(
    sequence_id="my-agent-run-001",
    step_order=["verify_identity", "assess_risk", "execute_transfer", "audit_ledger"],
)

seq.next("verify_identity")    # → ALLOW
seq.next("assess_risk")        # → ALLOW
seq.next("execute_transfer")   # → ALLOW
seq.next("audit_ledger")       # → ALLOW (seals sequence)

# Any out-of-order, replay, or post-seal call raises RailDenied
seq.next("verify_identity")    # → raises RailDenied: SEALED_SEQUENCE

Get a production API key at agenticrail.nz.

---

LangGraph integration

Wrap each node at add_node time. Uses thread_id from LangGraph config as the sequence_id — each graph invocation is isolated.

from langgraph.graph import StateGraph, END
from agenticrail import RailClient
from agenticrail.integrations.langgraph import LangGraphRail

client = RailClient(api_key="YOUR_KEY")
rail = LangGraphRail(
    client,
    step_order=["research", "analyze", "write_report", "review"],
)

builder = StateGraph(AgentState)

# Wrap each node — gate fires before node execution
builder.add_node("research",     rail.wrap("research",     research_fn))
builder.add_node("analyze",      rail.wrap("analyze",      analyze_fn))
builder.add_node("write_report", rail.wrap("write_report", write_report_fn))
builder.add_node("review",       rail.wrap("review",       review_fn))

builder.set_entry_point("research")
builder.add_edge("research",     "analyze")
builder.add_edge("analyze",      "write_report")
builder.add_edge("write_report", "review")
builder.add_edge("review",       END)

graph = builder.compile()

# thread_id → sequence_id: each invocation is independently tracked and verifiable
result = graph.invoke(
    {"query": "EU AI Act compliance checklist"},
    config={"configurable": {"thread_id": "run-2026-001"}},
)

What happens on DENY or HALT: rail.wrap() raises RailDenied inside the node. LangGraph catches unhandled node exceptions and halts graph execution. No subsequent nodes run.

Concurrent runs: Each thread_id is a separate sequence. Concurrent graph invocations with different thread IDs do not interfere — the gate tracks them independently via Durable Objects.

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CrewAI integration

Use guard.kickoff() instead of crew.kickoff(). Step[0] is gated before the crew starts; subsequent steps are gated via a task callback injected between tasks.

from crewai import Crew
from agenticrail import RailClient
from agenticrail.integrations.crewai import CrewRailGuard

client = RailClient(api_key="YOUR_KEY")
guard = CrewRailGuard(
    client,
    step_order=["research_task", "analysis_task", "write_task"],
)

crew = Crew(
    agents=[researcher, analyst, writer],
    tasks=[research_task, analysis_task, write_task],
)

# Drop-in replacement for crew.kickoff()
# Each call generates a fresh sequence_id — each run is independently tracked
result = guard.kickoff(crew, inputs={"topic": "AI governance"})

Note on blocking: CrewAI's task_callback fires synchronously between tasks, so the gate can block task N before task N starts. However, if CrewAI swallows exceptions in callbacks, a denied task may still execute. In that case, guard.kickoff() raises RailDenied after the crew finishes, preserving the denial in the audit trail.

For hard blocking (guaranteed pre-execution), use guard.gate() in a custom orchestration loop:

guard.reset()
for step, task_fn in zip(STEP_ORDER, task_functions):
    guard.gate(step)   # raises RailDenied immediately on DENY
    task_fn()

---

API reference

RailClient

client = RailClient(
    api_key="...",       # Required. Bearer token for the wrapper API.
    model_id="agent",    # Optional. Identifies your agent in receipts.
    base_url=None,       # Optional. Defaults to api.agenticrail.nz/v1/evaluate.
    timeout=10,          # Optional. Request timeout in seconds.
)

client.evaluate(sequence_id, step, *, ...)

decision = client.evaluate(
    sequence_id="my-run-001",
    step="verify_identity",
    action_type="CHECK_STATE",     # Optional. Default: CHECK_STATE.
    action="verify user identity", # Optional. Human-readable label.
    inputs={"user_id": "u123"},    # Optional. Metadata attached to receipt.
    step_order=[...],              # Required on every call — gate reads it from each payload.
    raise_on_deny=True,            # Optional. Default True.
)
# decision.decision  → "ALLOW" | "DENY" | "HALT"
# decision.allowed   → True if ALLOW
# decision.pack_id   → SHA-256 receipt hash
# decision.receipt   → full signed receipt dict
# decision.reasons   → list of reason codes on DENY/HALT

client.sequence(sequence_id, step_order)

Returns a RailSequence that tracks step_order state — call .next(step) for each step without managing step_order yourself.

RailDenied

try:
    seq.next("execute_transfer")
except RailDenied as e:
    print(e.decision)   # "DENY" or "HALT"
    print(e.reasons)    # ["SEQUENCE_VIOLATION"]
    print(e.pack_id)    # receipt hash for audit
    print(e.step)       # "execute_transfer"

LangGraphRail

rail = LangGraphRail(
    client,
    step_order=["step_a", "step_b", "step_c"],
    fallback_sequence_id=None,  # Used when thread_id not in config
)
wrapped_fn = rail.wrap("step_a", original_fn, action_type="CHECK_STATE")

CrewRailGuard

guard = CrewRailGuard(
    client,
    step_order=["task_1", "task_2", "task_3"],
    sequence_id=None,    # Optional. Auto-generated per kickoff() call if None.
    action_type="CHECK_STATE",
)
result = guard.kickoff(crew, inputs={...})
guard.gate("task_1")     # Explicit gate for custom loops
guard.reset()            # Reset state for a new run

---

Compliance reports

Every pack_id in a RailDecision is a verifiable receipt. Paste your sequence ID into the report generator or call it programmatically:

curl -X POST https://api.agenticrail.nz/v1/report \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"sequence_id": "my-run-001", "format": "json"}'

Returns: chain proof (Ed25519 signature verification, offline-reproducible; legacy HMAC k1 verified server-side for pre-cutover receipts), enforcement log, AI-written compliance narrative.

Demo sequences (using DEMO-AGENTICRAIL-PUBLIC-2026) are verifiable at report.agenticrail.nz — no auth needed.

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Action types

Type	Use when
CHECK_STATE	Reading or observing state (default)
VALIDATE_INPUT	Verifying inputs before acting
RECORD_RESULT	Writing or committing an outcome
CLARIFY_NEXT_STEP	Asking for clarification
SELECT_NEXT_STEP	Choosing a path
WAIT_FOR_SIGNAL	Pausing for an external trigger
PAUSE_CYCLE	Deliberate suspension
REDUCE_STIMULUS	Backing off

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Links

• API docs: agenticrail.nz/docs
• Interactive demo: agenticrail.nz/demo
• Compliance matrix: agenticrail.nz/compliance — what this actually provides, and what it does not
• Verify a sequence: report.agenticrail.nz

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TUARA KURI LIMITED — trading as AgenticRail. Hokianga, New Zealand.