ezop 0.0.21a0

Ezop SDK - The story of every AI agent

Ezop Python SDK

Ezop tracks the lifecycle of your AI agents — registrations, versions, and runs — so you have full observability across every deployment.

Documentation

Installation

pip install ezop

Configuration

export EZOP_API_KEY=your-ezop-api-key-here
export EZOP_API_URL=http://localhost:13000

---

Usage

Initialize the agent

from ezop import Agent

agent = Agent.init(
    name="customer-support-bot",
    owner="growth-team",
    version="v0.3",
    runtime="langchain",
    description="Handles tier-1 customer support tickets",
    default_permissions=["read:tickets"],
    permissions=["read:tickets", "write:replies"],
    changelog="Switched to new retrieval pipeline",
)

Call Agent.init() once at startup. It is safe to call on every deployment:

• If the agent does not exist, it will be created on the platform.
• If the agent already exists, registration returns the existing agent.
• If a new version is provided, the platform registers it as a new version under the same agent. If the version already exists, version registration is also a no-op.

Track runs

Agent.init() starts a run automatically. Call agent.close() when the invocation is done:

agent = Agent.init(name="my-bot", owner="my-team", version="v1.0", runtime="langchain")

agent.close(
    status="success",
    metadata={"user_id": user_id},
)

Track steps with spans and events

Use span for steps with duration and emit for single points in time:

# span: a record with start_time and end_time
with agent.span("retrieval", metadata={"query": user_input}):
    docs = retriever.search(user_input)

with agent.span("llm.call", metadata={"model": "claude"}):
    result = llm.generate(user_input)

# emit: a single point-in-time event
agent.emit(name="action.selected", category="reasoning")

agent.close(status="success")

Spans can be nested — child spans automatically record the parent's span_id as parent_id, enabling tree reconstruction:

with agent.span("model.prompt") as s1:
    plan = llm.plan(user_input)

    with agent.span("tool.call", metadata={"tool": "stripe.refund"}) as s2:
        refund = stripe.refund(plan.charge_id)
# produces: model.prompt → tool.call (parent_id links them)

Events emitted inside a span are automatically linked to that span via span_id:

with agent.span("llm.call") as s:
    agent.emit(name="token.count", category="llm", metadata={"tokens": 42})
# event.span_id == s.span_id

• Runs — the final outcome of a single agent invocation
• Spans — structured execution steps within a run (e.g. LLM call, retrieval, tool use)
• Events — raw logs inside a span

---

API Reference

agent.init()

Registers the agent and its version with the Ezop platform, and returns an Agent instance.

Parameter	Type	Required	Description
name	str	Yes	Agent name. Together with owner, uniquely identifies the agent on the platform.
owner	str	Yes	Team or user that owns the agent.
version	str	Yes	Version string (e.g. "v1.2.0"). A new version is registered if it does not exist yet.
runtime	str	Yes	Runtime or framework used (e.g. "langchain", "crew", "custom").
description	str	No	Human-readable description of the agent.
default_permissions	list[str]	No	Permissions granted to all versions of this agent by default.
permissions	list[str]	No	Permissions granted to this specific version.
changelog	str	No	Description of what changed in this version.

---

agent.close()

Closes the current run and records its outcome.

agent.close(
    status="success",
    message=None,
    metadata={"user_id": "u-123"},
)

Parameter	Type	Required	Description
status	str	Yes	Final status of the run. One of "success", "failed", "partial", "canceled", "running".
message	str	No	Human-readable message describing the outcome, e.g. a failure reason.
metadata	dict	No	Any arbitrary JSON-serialisable data you want to attach to the run (e.g. user context, request identifiers, feature flags).

---

agent.emit()

Emits an event on the current run. Events capture discrete steps within a run such as LLM calls, tool invocations, or retrieval operations.

agent.emit(
    name="llm.response",
    category="llm",
    type="llm_response",
    subtype="chain_of_thought",  # optional
    span_id="...",               # optional, auto-set inside a span
    iteration_id=1,              # optional, for loop tracking
    input={"prompt": "hello"},
    output={"text": "hi"},
    metadata={
        "model": "claude-sonnet-4-6",
        "usage": {
            "input_tokens": 12,
            "output_tokens": 8,
        },
    },
    error={"message": "..."},    # optional, jsonb
)

Parameter	Type	Required	Description
name	str	Yes	Event name.
category	str	Yes	Top-level category — must be one of the values below.
type	str	No	Specific action type — must match category (see table below).
subtype	str	No	Optional detail layer — see valid values below.
span_id	str	No	Links this event to a span. Auto-set when emitting inside a span context manager.
iteration_id	int	No	Loop iteration counter, useful for agentic loops.
input	any	No	Input passed to this step.
output	any	No	Output produced by this step.
metadata	dict	No	Any arbitrary JSON-serialisable data. For LLM events, include usage.input_tokens and usage.output_tokens for cost tracking (see below).
error	dict	No	Error details as a JSON object, e.g. {"message": "timeout"}.

category values and their valid type values:

category	type values
llm	llm_request, llm_response
tool	tool_call_started, tool_call_completed, tool_call_failed, tool_retry
reasoning	reasoning_step, reasoning_plan, reasoning_reflection, reasoning_decision, reasoning_final
agent	agent_run_started, agent_run_completed, agent_run_failed
memory	memory_query, memory_retrieval, memory_write
system	span_started, span_completed
user	user_input, user_feedback
cost	cost_calculated
error	error_raised

subtype values:

Group	Values
Reasoning patterns	chain_of_thought, react, reflection, self_consistency
Tool subtypes	http, database, filesystem, api
Error subtypes	timeout, rate_limit, validation, tool_error, llm_error

For LLM events, always include token usage and model in metadata to enable cost tracking:

agent.emit(
    name="llm.call",
    category="llm",
    metadata={
        "model": "claude-opus-4-5",
        "usage": {
            "input_tokens": 12,
            "output_tokens": 8,
        },
    },
)

Popular LLMs return token usage in their responses — map it directly.

---

agent.span()

Returns a context manager that tracks a scoped duration as a span record. On enter it creates the span with a start_time; on exit it updates the span with an end_time.

with agent.span("llm.call", metadata={"model": "claude"}) as s:
    result = llm.generate(prompt)

Parameter	Type	Required	Description
name	str	Yes	Span name (e.g. "llm.call", "tool.invoke").
metadata	dict	No	Any arbitrary JSON-serialisable data to attach to the span.

Nested spans automatically propagate context — each child span records the enclosing span's id as its parent_id, enabling tree reconstruction:

model.prompt  (id: A, parent_id: None)
  └── tool.call  (id: B, parent_id: A)
        └── memory.read  (id: C, parent_id: B)

Events emitted inside a span are automatically linked to that span via span_id.

---

Logging

The SDK uses Python's standard logging module under the ezop namespace. To enable logs in your application:

import logging
logging.getLogger("ezop").setLevel(logging.DEBUG)