Fixed-order calls#
Call the LLM (optionally) while invoking multiple sub-functions in an order hard-coded in Python.
When to use#
- Research pipeline: survey → find gaps → generate ideas
- Paper pipeline: draft → review → revise
- Data pipeline: collect → clean → analyze
- Any multi-step task whose step order is known ahead of time
Design points#
- Use the
@agentic_functiondecorator - Call multiple sub-
@agentic_functions in a fixed order exec()is optional: skip it (pure chaining), or call it multiple times (each call creates one exec child node)- Data flows between sub-functions through plain Python variables
- One function may call
exec()multiple times AND call any number of other@agentic_functions
Example: no exec, pure chaining#
from openprogram import agentic_function
@agentic_function(input={
"task": {"description": "Research topic."},
})
def research_pipeline(task: str, runtime=None) -> dict:
"""Run the full research pipeline: survey, find gaps, generate ideas."""
survey = survey_topic(topic=task, runtime=runtime)
gaps = identify_gaps(survey=survey, runtime=runtime)
ideas = generate_ideas(gaps=gaps, runtime=runtime)
return {"survey": survey, "gaps": gaps, "ideas": ideas}
Example: one exec call to summarise#
@agentic_function(input={
"task": {"description": "Research topic."},
})
def research_pipeline(task: str, runtime=None) -> str:
"""Run the full research pipeline and summarise the results."""
survey = survey_topic(topic=task, runtime=runtime)
gaps = identify_gaps(survey=survey, runtime=runtime)
ideas = generate_ideas(gaps=gaps, runtime=runtime)
return runtime.exec(content=[
{"type": "text", "text": (
f"Survey:\n{survey}\n\n"
f"Gaps:\n{gaps}\n\n"
f"Ideas:\n{ideas}"
)},
])
Session DAG#
Each call is one node; the caller edge points at the orchestrator:
research_pipeline
├── survey_topic ← step 1
├── identify_gaps ← step 2
└── generate_ideas ← step 3
Passing data between steps#
Sub-functions hand data to each other through Python variables — no LLM involved:
survey = survey_topic(topic=task, runtime=runtime)
gaps = identify_gaps(survey=survey, runtime=runtime)
The return value of survey_topic goes straight in as the input argument of
identify_gaps.
Inserting Python processing between steps#
survey = survey_topic(topic=task, runtime=runtime)
# plain Python processing in between
key_points = extract_key_points(survey)
filtered = [p for p in key_points if p["relevance"] > 0.5]
gaps = identify_gaps(survey="\n".join(filtered), runtime=runtime)
Error handling#
The primary mechanism is exception propagation: when a sub-function raises,
its DAG node is recorded with status='error' and the exception re-raises
into the orchestrator. Catch it there with a plain try/except:
try:
survey = survey_topic(topic=task, runtime=runtime)
except Exception as e:
return {"error": f"Survey failed: {e}"}
gaps = identify_gaps(survey=survey, runtime=runtime)
Optionally, if a sub-function reports failure in-band (returning an error string instead of raising), check the value:
survey = survey_topic(topic=task, runtime=runtime)
if not survey or "error" in survey.lower():
return {"error": "Survey failed", "survey": survey}
gaps = identify_gaps(survey=survey, runtime=runtime)
Versus "LLM-selected calls"#
| Fixed-order calls | Tool calling / next-step decision | |
|---|---|---|
| Who decides the call order | Python code | The LLM |
| How many sub-functions run | Several, all of them | Tool loop: many, across rounds; decision menu: one |
| Flexibility | Fixed pipeline | Varies with the task |
Last updated · 2026-08-13