Code-Execution Agent in Python: Full Example

agent-patterns/
└── code-execution-agent/
    └── python/
        ├── main.py
        ├── gateway.py
        ├── agent.py
        ├── context.py
        ├── README.md
        └── requirements.txt

git clone https://github.com/AgentPatterns-tech/agentpatterns.git
cd agentpatterns

cd agent-patterns/code-execution-agent/python
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

export OPENAI_API_KEY="sk-..."
# optional:
# export OPENAI_MODEL="gpt-4.1-mini"
# export OPENAI_TIMEOUT_SECONDS="60"

python main.py

from __future__ import annotations

from typing import Any


def build_request(*, report_date: str, region: str, incident_id: str) -> dict[str, Any]:
    transactions: list[dict[str, Any]] = []
    for idx in range(60):
        is_failed = idx in {7, 34}
        transactions.append(
            {
                "transaction_id": f"txn_{idx + 1:03d}",
                "status": "failed" if is_failed else "paid",
                "chargeback": idx == 34,
                "latency_ms": 150 + (idx % 40) + (25 if is_failed else 0),
            }
        )

    return {
        "request": {
            "report_date": report_date,
            "region": region.upper(),
            "incident_id": incident_id,
            "transactions": transactions,
        },
        "policy_hints": {
            "allowed_languages": ["python", "javascript"],
            "max_code_chars": 2400,
            "exec_timeout_seconds": 2.0,
            "network_access": "denied",
        },
    }

from __future__ import annotations

from typing import Any


def propose_code_execution_plan(*, goal: str, request: dict[str, Any]) -> dict[str, Any]:
    req = request["request"]
    del goal

    code = """
import json
import statistics

payload = json.loads(input())
rows = payload["transactions"]

total = len(rows)
failed = sum(1 for row in rows if row["status"] != "paid")
chargeback_alerts = sum(1 for row in rows if row.get("chargeback") is True)
failed_rate = (failed / total) if total else 0.0

latencies = [float(row["latency_ms"]) for row in rows]
avg_latency = statistics.fmean(latencies) if latencies else 0.0

if latencies:
    sorted_latencies = sorted(latencies)
    p95_idx = int(round((len(sorted_latencies) - 1) * 0.95))
    p95_latency = sorted_latencies[p95_idx]
else:
    p95_latency = 0.0

severity = "P1" if failed_rate >= 0.03 else "P2"
eta_minutes = 45 if severity == "P1" else 20

print(
    json.dumps(
        {
            "failed_payment_rate": failed_rate,
            "chargeback_alerts": chargeback_alerts,
            "incident_severity": severity,
            "eta_minutes": eta_minutes,
            "affected_checkout_share": failed_rate,
            "avg_latency_ms": avg_latency,
            "p95_latency_ms": p95_latency,
            "sample_size": total,
            "incident_id": payload["incident_id"],
            "region": payload["region"],
        },
        separators=(",", ":"),
    )
)
""".strip()

    return {
        "action": {
            "id": "c1",
            "language": "python",
            "entrypoint": "main.py",
            "code": code,
            "input_payload": {
                "incident_id": req["incident_id"],
                "region": req["region"],
                "transactions": req["transactions"],
            },
        }
    }


def compose_final_answer(
    *,
    request: dict[str, Any],
    aggregate: dict[str, Any],
    execution_summary: dict[str, Any],
) -> str:
    req = request["request"]
    metrics = aggregate["metrics"]

    return (
        f"Code execution brief ({req['region']}, {req['report_date']}): incident {req['incident_id']} is "
        f"{metrics['incident_severity']} with failed payments at {metrics['failed_payment_rate_pct']}% and "
        f"{metrics['chargeback_alerts']} chargeback alerts. Affected checkout share is "
        f"{metrics['affected_checkout_share_pct']}%, average latency is {metrics['avg_latency_ms']} ms "
        f"(p95 {metrics['p95_latency_ms']} ms), and ETA is ~{metrics['eta_minutes']} minutes. "
        f"Executed in a separate subprocess boundary (best-effort, not a security sandbox) "
        f"({execution_summary['exec_ms']} ms, {execution_summary['stdout_bytes']} stdout bytes, "
        f"{execution_summary['stderr_bytes']} stderr bytes)."
    )

from __future__ import annotations

import ast
import hashlib
import json
import os
import subprocess
import sys
import tempfile
import time
from dataclasses import dataclass
from pathlib import Path
from typing import Any


class StopRun(Exception):
    def __init__(self, reason: str, *, details: dict[str, Any] | None = None):
        super().__init__(reason)
        self.reason = reason
        self.details = details or {}


@dataclass(frozen=True)
class Budget:
    max_seconds: int = 25
    max_code_chars: int = 2400
    exec_timeout_seconds: float = 2.0
    max_stdout_bytes: int = 4096
    max_stderr_bytes: int = 4096


@dataclass(frozen=True)
class Decision:
    kind: str
    reason: str


ALLOWED_IMPORTS = {"json", "statistics"}
# Blocked function calls in generated code.
DENIED_CALL_NAMES = {"exec", "eval", "compile", "__import__", "open"}
# NOTE: heuristic hardening — blocks suspicious attribute names regardless of receiver type.
DENIED_CALL_ATTRS = {"system", "popen", "fork", "spawn", "connect", "request", "urlopen"}
# Blocked global name references in generated code (introspection/indirection primitives).
DENIED_NAME_REFERENCES = {
    "builtins",
    "getattr",
    "setattr",
    "delattr",
    "globals",
    "locals",
    "vars",
    "dir",
}
# Blocked identifier references in generated code (belt-and-suspenders hardening).
DENIED_GLOBAL_NAMES = {"os", "sys", "subprocess", "socket", "pathlib", "importlib"}


def code_hash(code: str) -> str:
    return hashlib.sha256(code.encode("utf-8")).hexdigest()[:16]


def validate_code_action(raw: Any, *, max_code_chars: int) -> dict[str, Any]:
    if not isinstance(raw, dict):
        raise StopRun("invalid_action:not_object")

    action_id = raw.get("id")
    language = raw.get("language")
    entrypoint = raw.get("entrypoint")
    code = raw.get("code")
    input_payload = raw.get("input_payload")

    if not isinstance(action_id, str) or not action_id.strip():
        raise StopRun("invalid_action:id")
    if not isinstance(language, str) or not language.strip():
        raise StopRun("invalid_action:language")
    if not isinstance(entrypoint, str) or not entrypoint.strip():
        raise StopRun("invalid_action:entrypoint")
    if not isinstance(code, str) or not code.strip():
        raise StopRun("invalid_action:code")
    if len(code) > max_code_chars:
        raise StopRun("invalid_action:code_too_long")
    if not isinstance(input_payload, dict):
        raise StopRun("invalid_action:input_payload")

    normalized_entrypoint = entrypoint.strip()
    if "/" in normalized_entrypoint or "\\" in normalized_entrypoint:
        raise StopRun("invalid_action:entrypoint_path")
    if normalized_entrypoint != "main.py":
        raise StopRun("invalid_action:entrypoint_denied")

    return {
        "id": action_id.strip(),
        "language": language.strip().lower(),
        "entrypoint": normalized_entrypoint,
        "code": code,
        "input_payload": input_payload,
    }


def validate_execution_output(raw: Any) -> dict[str, Any]:
    if not isinstance(raw, dict):
        raise StopRun("invalid_code_output:not_object")

    required = {
        "failed_payment_rate",
        "chargeback_alerts",
        "incident_severity",
        "eta_minutes",
        "affected_checkout_share",
        "avg_latency_ms",
        "p95_latency_ms",
        "sample_size",
        "incident_id",
        "region",
    }
    if not required.issubset(set(raw.keys())):
        raise StopRun("invalid_code_output:missing_required")

    failed_rate = raw["failed_payment_rate"]
    if not isinstance(failed_rate, (int, float)) or not (0 <= float(failed_rate) <= 1):
        raise StopRun("invalid_code_output:failed_payment_rate")

    share = raw["affected_checkout_share"]
    if not isinstance(share, (int, float)) or not (0 <= float(share) <= 1):
        raise StopRun("invalid_code_output:affected_checkout_share")

    chargeback_alerts = raw["chargeback_alerts"]
    if not isinstance(chargeback_alerts, int) or chargeback_alerts < 0:
        raise StopRun("invalid_code_output:chargeback_alerts")

    severity = raw["incident_severity"]
    if severity not in {"P1", "P2", "P3"}:
        raise StopRun("invalid_code_output:incident_severity")

    eta = raw["eta_minutes"]
    if not isinstance(eta, int) or eta < 0 or eta > 240:
        raise StopRun("invalid_code_output:eta_minutes")

    sample_size = raw["sample_size"]
    if not isinstance(sample_size, int) or sample_size <= 0:
        raise StopRun("invalid_code_output:sample_size")

    try:
        avg_latency = round(float(raw["avg_latency_ms"]), 2)
    except (TypeError, ValueError):
        raise StopRun("invalid_code_output:avg_latency_ms")
    try:
        p95_latency = round(float(raw["p95_latency_ms"]), 2)
    except (TypeError, ValueError):
        raise StopRun("invalid_code_output:p95_latency_ms")

    return {
        "failed_payment_rate": float(failed_rate),
        "chargeback_alerts": chargeback_alerts,
        "incident_severity": severity,
        "eta_minutes": eta,
        "affected_checkout_share": float(share),
        "avg_latency_ms": avg_latency,
        "p95_latency_ms": p95_latency,
        "sample_size": sample_size,
        "incident_id": str(raw["incident_id"]),
        "region": str(raw["region"]).upper(),
    }


def _static_policy_violations(code: str) -> list[str]:
    lower = code.lower()
    violations: list[str] = []
    input_calls = 0

    if "http://" in lower or "https://" in lower:
        violations.append("network_literal_blocked")

    try:
        tree = ast.parse(code)
    except SyntaxError:
        return ["syntax_error"]

    for node in ast.walk(tree):
        if isinstance(node, ast.Import):
            for alias in node.names:
                module = alias.name.split(".")[0]
                if module not in ALLOWED_IMPORTS:
                    violations.append(f"import_not_allowed:{module}")
        elif isinstance(node, ast.ImportFrom):
            module = (node.module or "").split(".")[0]
            if module not in ALLOWED_IMPORTS:
                violations.append(f"import_not_allowed:{module or 'relative'}")
        elif isinstance(node, ast.Name):
            if node.id.startswith("__"):
                violations.append(f"name_not_allowed:{node.id}")
            elif node.id in DENIED_NAME_REFERENCES:
                violations.append(f"name_not_allowed:{node.id}")
            elif node.id in DENIED_GLOBAL_NAMES:
                violations.append(f"name_not_allowed:{node.id}")
        elif isinstance(node, ast.Attribute):
            if node.attr.startswith("__"):
                violations.append(f"attr_not_allowed:{node.attr}")
            elif node.attr in DENIED_CALL_ATTRS:
                violations.append(f"attr_not_allowed:{node.attr}")
        elif isinstance(node, ast.Call):
            if isinstance(node.func, ast.Name) and node.func.id in DENIED_CALL_NAMES:
                violations.append(f"call_not_allowed:{node.func.id}")
            elif isinstance(node.func, ast.Name) and node.func.id in {"getattr", "setattr", "delattr"}:
                violations.append(f"call_not_allowed:{node.func.id}")
            elif isinstance(node.func, ast.Name) and node.func.id == "input":
                input_calls += 1
            elif isinstance(node.func, ast.Attribute) and node.func.attr in DENIED_CALL_ATTRS:
                violations.append(f"call_not_allowed:{node.func.attr}")

    if input_calls > 1:
        violations.append("too_many_input_reads")

    return sorted(set(violations))


class CodeExecutionGateway:
    def __init__(
        self,
        *,
        allowed_languages_policy: set[str],
        allowed_languages_execution: set[str],
        budget: Budget,
    ):
        self.allowed_languages_policy = {item.lower() for item in allowed_languages_policy}
        self.allowed_languages_execution = {item.lower() for item in allowed_languages_execution}
        self.budget = budget

    def evaluate(self, *, action: dict[str, Any]) -> Decision:
        language = action["language"]
        if language not in self.allowed_languages_policy:
            return Decision(kind="deny", reason="language_denied_policy")
        if language not in self.allowed_languages_execution:
            return Decision(kind="deny", reason="language_denied_execution")

        violations = _static_policy_violations(action["code"])
        if violations:
            return Decision(kind="deny", reason=f"static_policy_violation:{','.join(violations[:3])}")
        return Decision(kind="allow", reason="policy_pass")

    def execute_python(self, *, code: str, entrypoint: str, input_payload: dict[str, Any]) -> dict[str, Any]:
        if entrypoint != "main.py":
            raise StopRun("invalid_action:entrypoint_denied")

        with tempfile.TemporaryDirectory(prefix="code_exec_agent_") as temp_dir:
            script_path = Path(temp_dir) / entrypoint
            script_path.write_text(code, encoding="utf-8")

            # Minimal hardening for interpreter behavior in this demo boundary.
            proc_env = os.environ.copy()
            proc_env["PYTHONNOUSERSITE"] = "1"
            proc_env["PYTHONDONTWRITEBYTECODE"] = "1"

            started = time.monotonic()
            try:
                proc = subprocess.run(
                    [sys.executable, str(script_path)],
                    input=json.dumps(input_payload),
                    text=True,
                    encoding="utf-8",
                    errors="replace",
                    capture_output=True,
                    timeout=self.budget.exec_timeout_seconds,
                    cwd=temp_dir,
                    env=proc_env,
                )
            except subprocess.TimeoutExpired as exc:
                raise StopRun("code_timeout") from exc

            exec_ms = int((time.monotonic() - started) * 1000)
            stdout = proc.stdout or ""
            stderr = proc.stderr or ""
            # Demo limitation: size caps are checked after process completion.
            stdout_bytes = len(stdout.encode("utf-8"))
            stderr_bytes = len(stderr.encode("utf-8"))
            if stdout_bytes > self.budget.max_stdout_bytes:
                raise StopRun("code_output_too_large")
            if stderr_bytes > self.budget.max_stderr_bytes:
                raise StopRun("code_stderr_too_large")
            if proc.returncode != 0:
                stderr_snippet = stderr.strip().replace("\n", " ")[:200]
                stdout_snippet = stdout.strip().replace("\n", " ")[:200]
                details: dict[str, str] = {}
                if stderr_snippet:
                    details["stderr_snippet"] = stderr_snippet
                if stdout_snippet:
                    details["stdout_snippet"] = stdout_snippet
                raise StopRun(
                    f"code_runtime_error:{proc.returncode}",
                    details=details,
                )

            stdout = stdout.strip()
            if not stdout:
                raise StopRun("invalid_code_output:empty_stdout")

            try:
                payload = json.loads(stdout)
            except json.JSONDecodeError as exc:
                raise StopRun("invalid_code_output:non_json") from exc

            if not isinstance(payload, dict):
                raise StopRun("invalid_code_output:not_object")

            return {
                "payload": payload,
                "exec_ms": exec_ms,
                "stdout_bytes": stdout_bytes,
                "stderr_bytes": stderr_bytes,
            }

from __future__ import annotations

import json
import math
import time
import uuid
from typing import Any

from agent import compose_final_answer, propose_code_execution_plan
from context import build_request
from gateway import (
    Budget,
    CodeExecutionGateway,
    StopRun,
    code_hash,
    validate_code_action,
    validate_execution_output,
)

GOAL = (
    "Run a safe code task to compute incident metrics from payment transactions "
    "and return an operations-ready summary."
)
REQUEST = build_request(
    report_date="2026-03-07",
    region="US",
    incident_id="inc_payments_20260307",
)

DEFAULT_BUDGET = Budget(
    max_seconds=25,
    max_code_chars=2400,
    exec_timeout_seconds=2.0,
    max_stdout_bytes=4096,
    max_stderr_bytes=4096,
)

DEFAULT_ALLOWED_LANGUAGES_POLICY = {"python", "javascript"}
ALLOWED_LANGUAGES_EXECUTION = {"python"}


def run_code_execution_agent(*, goal: str, request: dict[str, Any]) -> dict[str, Any]:
    run_id = str(uuid.uuid4())
    started = time.monotonic()
    trace: list[dict[str, Any]] = []
    history: list[dict[str, Any]] = []

    hints_raw = request.get("policy_hints")
    hints: dict[str, Any] = hints_raw if isinstance(hints_raw, dict) else {}
    network_access = str(hints.get("network_access", "denied")).strip().lower()
    if network_access not in {"denied", "none", "off"}:
        return {
            "run_id": run_id,
            "status": "stopped",
            "stop_reason": "invalid_request:network_access_must_be_denied",
            "phase": "plan",
            "trace": trace,
            "history": history,
        }

    allowed_policy_raw = hints.get("allowed_languages")
    if isinstance(allowed_policy_raw, list):
        allowed_policy = {
            str(item).strip().lower()
            for item in allowed_policy_raw
            if isinstance(item, str) and item.strip()
        }
    else:
        allowed_policy = set(DEFAULT_ALLOWED_LANGUAGES_POLICY)
    if not allowed_policy:
        allowed_policy = set(DEFAULT_ALLOWED_LANGUAGES_POLICY)

    max_code_chars_raw = hints.get("max_code_chars", DEFAULT_BUDGET.max_code_chars)
    exec_timeout_raw = hints.get("exec_timeout_seconds", DEFAULT_BUDGET.exec_timeout_seconds)
    try:
        max_code_chars = int(max_code_chars_raw)
    except (TypeError, ValueError):
        max_code_chars = DEFAULT_BUDGET.max_code_chars
    try:
        exec_timeout_seconds = float(exec_timeout_raw)
        if not math.isfinite(exec_timeout_seconds):
            raise ValueError
    except (TypeError, ValueError):
        exec_timeout_seconds = DEFAULT_BUDGET.exec_timeout_seconds

    budget = Budget(
        max_seconds=DEFAULT_BUDGET.max_seconds,
        max_code_chars=max(200, min(8000, max_code_chars)),
        exec_timeout_seconds=max(0.2, min(20.0, exec_timeout_seconds)),
        max_stdout_bytes=DEFAULT_BUDGET.max_stdout_bytes,
        max_stderr_bytes=DEFAULT_BUDGET.max_stderr_bytes,
    )

    gateway = CodeExecutionGateway(
        allowed_languages_policy=allowed_policy,
        allowed_languages_execution=ALLOWED_LANGUAGES_EXECUTION,
        budget=budget,
    )

    def stopped(stop_reason: str, *, phase: str, **extra: Any) -> dict[str, Any]:
        payload = {
            "run_id": run_id,
            "status": "stopped",
            "stop_reason": stop_reason,
            "phase": phase,
            "trace": trace,
            "history": history,
        }
        payload.update(extra)
        return payload

    phase = "plan"
    try:
        if (time.monotonic() - started) > budget.max_seconds:
            return stopped("max_seconds", phase=phase)

        raw_plan = propose_code_execution_plan(goal=goal, request=request)
        action = validate_code_action(raw_plan.get("action"), max_code_chars=budget.max_code_chars)
        generated_code_hash = code_hash(action["code"])

        trace.append(
            {
                "step": 1,
                "phase": "plan_code",
                "action_id": action["id"],
                "language": action["language"],
                "code_hash": generated_code_hash,
                "chars": len(action["code"]),
                "ok": True,
            }
        )
        history.append(
            {
                "step": 1,
                "action": "propose_code_execution_plan",
                "proposed_action": {
                    "id": action["id"],
                    "language": action["language"],
                    "entrypoint": action["entrypoint"],
                    "code_hash": generated_code_hash,
                },
            }
        )

        phase = "policy_check"
        decision = gateway.evaluate(action=action)
        trace.append(
            {
                "step": 2,
                "phase": "policy_check",
                "decision": decision.kind,
                "reason": decision.reason,
                "allowed_languages_policy": sorted(allowed_policy),
                "allowed_languages_execution": sorted(ALLOWED_LANGUAGES_EXECUTION),
                "ok": decision.kind == "allow",
            }
        )
        history.append(
            {
                "step": 2,
                "action": "policy_check",
                "decision": {
                    "kind": decision.kind,
                    "reason": decision.reason,
                },
            }
        )
        if decision.kind != "allow":
            return stopped(f"policy_block:{decision.reason}", phase=phase)

        if (time.monotonic() - started) > budget.max_seconds:
            return stopped("max_seconds", phase="execute")

        phase = "execute"
        execute_trace = {
            "step": 3,
            "phase": "execute_code",
            "language": action["language"],
            "code_hash": generated_code_hash,
            "ok": False,
        }
        trace.append(execute_trace)
        try:
            execution = gateway.execute_python(
                code=action["code"],
                entrypoint=action["entrypoint"],
                input_payload=action["input_payload"],
            )
            validated = validate_execution_output(execution["payload"])
        except StopRun as exc:
            execute_trace["error"] = exc.reason
            details = exc.details if isinstance(exc.details, dict) else {}
            stderr_snippet = str(details.get("stderr_snippet", "")).strip()
            stdout_snippet = str(details.get("stdout_snippet", "")).strip()
            if stderr_snippet:
                execute_trace["stderr_snippet"] = stderr_snippet
            if stdout_snippet:
                execute_trace["stdout_snippet"] = stdout_snippet
            history.append(
                {
                    "step": 3,
                    "action": "execute_code",
                    "status": "error",
                    "reason": exc.reason,
                    **({"stderr_snippet": stderr_snippet} if stderr_snippet else {}),
                    **({"stdout_snippet": stdout_snippet} if stdout_snippet else {}),
                }
            )
            raise

        execute_trace["stdout_bytes"] = execution["stdout_bytes"]
        execute_trace["stderr_bytes"] = execution["stderr_bytes"]
        execute_trace["exec_ms"] = execution["exec_ms"]
        execute_trace["ok"] = True
        history.append(
            {
                "step": 3,
                "action": "execute_code",
                "result": validated,
            }
        )

        aggregate = {
            "report_date": request["request"]["report_date"],
            "region": request["request"]["region"],
            "incident_id": request["request"]["incident_id"],
            "metrics": {
                "incident_severity": validated["incident_severity"],
                "failed_payment_rate": round(validated["failed_payment_rate"], 6),
                "failed_payment_rate_pct": round(validated["failed_payment_rate"] * 100, 2),
                "chargeback_alerts": validated["chargeback_alerts"],
                "eta_minutes": validated["eta_minutes"],
                "affected_checkout_share": round(validated["affected_checkout_share"], 6),
                "affected_checkout_share_pct": round(validated["affected_checkout_share"] * 100, 2),
                "avg_latency_ms": validated["avg_latency_ms"],
                "p95_latency_ms": validated["p95_latency_ms"],
                "sample_size": validated["sample_size"],
            },
        }
        execution_summary = {
            "language": action["language"],
            "code_hash": generated_code_hash,
            "exec_ms": execution["exec_ms"],
            "stdout_bytes": execution["stdout_bytes"],
            "stderr_bytes": execution["stderr_bytes"],
        }
        answer = compose_final_answer(
            request=request,
            aggregate=aggregate,
            execution_summary=execution_summary,
        )

        trace.append(
            {
                "step": 4,
                "phase": "finalize",
                "ok": True,
            }
        )
        history.append(
            {
                "step": 4,
                "action": "finalize",
            }
        )

        return {
            "run_id": run_id,
            "status": "ok",
            "stop_reason": "success",
            "outcome": "code_execution_success",
            "answer": answer,
            "proposed_action": {
                "id": action["id"],
                "language": action["language"],
                "entrypoint": action["entrypoint"],
                "code_hash": generated_code_hash,
            },
            "aggregate": aggregate,
            "execution": execution_summary,
            "trace": trace,
            "history": history,
        }
    except StopRun as exc:
        return stopped(exc.reason, phase=phase)


def main() -> None:
    result = run_code_execution_agent(goal=GOAL, request=REQUEST)
    print(json.dumps(result, indent=2, ensure_ascii=False))


if __name__ == "__main__":
    main()

{
  "run_id": "5506a01d-01a1-47e8-88c9-24eb0d1dff39",
  "status": "ok",
  "stop_reason": "success",
  "outcome": "code_execution_success",
  "answer": "Code execution brief (US, 2026-03-07): incident inc_payments_20260307 is P1 with failed payments at 3.33% and 1 chargeback alerts. Affected checkout share is 3.33%, average latency is 167.0 ms (p95 187.0 ms), and ETA is ~45 minutes. Executed in a separate subprocess boundary (best-effort, not a security sandbox) (25 ms, 269 stdout bytes, 0 stderr bytes).",
  "proposed_action": {
    "id": "c1",
    "language": "python",
    "entrypoint": "main.py",
    "code_hash": "47a5c01dd74664c7"
  },
  "aggregate": {
    "report_date": "2026-03-07",
    "region": "US",
    "incident_id": "inc_payments_20260307",
    "metrics": {
      "incident_severity": "P1",
      "failed_payment_rate": 0.033333,
      "failed_payment_rate_pct": 3.33,
      "chargeback_alerts": 1,
      "eta_minutes": 45,
      "affected_checkout_share": 0.033333,
      "affected_checkout_share_pct": 3.33,
      "avg_latency_ms": 167.0,
      "p95_latency_ms": 187.0,
      "sample_size": 60
    }
  },
  "execution": {
    "language": "python",
    "code_hash": "47a5c01dd74664c7",
    "exec_ms": 25,
    "stdout_bytes": 269,
    "stderr_bytes": 0
  },
  "trace": [
    {
      "step": 1,
      "phase": "plan_code",
      "action_id": "c1",
      "language": "python",
      "code_hash": "47a5c01dd74664c7",
      "chars": 1229,
      "ok": true
    },
    {
      "step": 2,
      "phase": "policy_check",
      "decision": "allow",
      "reason": "policy_pass",
      "allowed_languages_policy": ["javascript", "python"],
      "allowed_languages_execution": ["python"],
      "ok": true
    },
    {
      "step": 3,
      "phase": "execute_code",
      "language": "python",
      "code_hash": "47a5c01dd74664c7",
      "ok": true,
      "stdout_bytes": 269,
      "stderr_bytes": 0,
      "exec_ms": 25
    },
    {
      "step": 4,
      "phase": "finalize",
      "ok": true
    }
  ],
  "history": [{...}]
}