Using Pydantic with Gemini 2.5 Flash Lite Preview 09-2025 on OpenRouter
This tutorial explains how to use a Pydantic schema to extract structured data using Gemini 2.5 Flash Lite Preview 09-2025.
Please read this tutorial first to understand the basic setup
Code:
import os
import json
import requests
import datetime
from inputs import get_input_text
from system import system_instruction_1 as system_instruction
from schema import VAERSReport
from dotenv import load_dotenv
import time
load_dotenv()
model_name = 'google/gemini-2.5-flash-lite-preview-09-2025'
api_key = os.getenv("OPENROUTER_API_KEY")
json_schema_text = json.dumps(VAERSReport.model_json_schema(), indent=2)
input_text, sentence_map = get_input_text()
prompt = f"""
Report: {input_text}
JSON Schema:
{json_schema_text}
"""
url = "https://openrouter.ai/api/v1/chat/completions"
headers = {
"Authorization": f"Bearer {api_key}",
"Content-Type": "application/json",
"HTTP-Referer": "https://botflo.com/", # Optional. Site URL for rankings on openrouter.ai.
"X-Title": "LLM Accuracy Comparisons for Structured Outputs", # Optional
}
payload = {
"model": model_name,
"messages": [
{"role": "system", "content": f'{system_instruction}'},
{"role": "user", "content": f'{prompt}'}
],
"reasoning": {
"effort": "high"
}
}
before = time.time()
response_full = requests.post(url, headers=headers, data=json.dumps(payload))
elapsed = time.time() - before
response = response_full.json()
metadata = {
"metrics": {
"elapsed": elapsed,
"usage": response['usage']
},
"text": {
"system_instruction": system_instruction,
"sentence_map": sentence_map,
"json_schema_text": json_schema_text
}
}
response["metadata"] = metadata
response_file_name = f"responses/response_{model_name.replace('/', '-')}.json"
with open(response_file_name, 'w+') as f:
json.dump(response, f, indent=2)
output_text = response.get('choices')[0].get('message').get('content')
print(output_text)
input_file_name = f"inputs/input_{model_name.replace('/', '-')}.txt"
with open(input_file_name, 'w+') as f:
f.write(input_text)
output_file_name = f"outputs/output_{model_name.replace('/', '-')}.txt"
with open(output_file_name, 'w+') as f:
f.write(output_text)LLM Response:
```json
{
"timeline": {
"date_of_vaccination": {
"year": 1999,
"month": 6,
"citations": [
3
],
"explanation": "Vaccination date listed for multiple vaccines administered includes 1999-06-30"
},
"regression_onset_date": {
"year": 2000,
"month": 1,
"citations": [
146,
3,
42,
43
],
"explanation": "Regression onset cited between 21-23 months [146]. Based on age 15.96 months at vaccination (6/30/99) [3], onset occurred approximately 6 months later in January 2000."
},
"diagnosis_date": {
"year": 2001,
"month": 1,
"citations": [
98
],
"explanation": "Evaluation conducted on 1/4/01 where PDD concern was primary focus."
},
"age_at_vaccination_months": {
"value": 15.96,
"citations": [
3
],
"explanation": "Age listed as 1.33 years [3], calculated as 15.96 months."
},
"age_at_diagnosis_months": {
"value": 21,
"citations": [
99
],
"explanation": "Parents became concerned about language delay around 18 months [99]. Regression onset around 21-23 months [146]."
}
},
"developmental_milestones": [
{
"milestone_name": {
"value": "sitting_without_support",
"citations": [
41
],
"explanation": "Subject sat without support at 8 months (6 adjusted for prematurity)"
},
"milestone_type": "adaptive_behavior",
"milestone_age_in_months": {
"value": 8,
"citations": [
41
],
"explanation": "Sat without support at 8 months (6 adjusted)"
},
"milestone_has_regressed": {
"value": true,
"citations": [
110,
132
],
"explanation": "Developmental regression noted"
},
"regression_start_date_in_months": {
"value": 22,
"citations": [
146
],
"explanation": "Regression onset between 21-23 months"
},
"progressed_after_regression": {
"value": false,
"citations": [
162
],
"explanation": "Autism persisted as of July 2002, no mention of regression reversal."
}
},
{
"milestone_name": {
"value": "walking",
"citations": [
41
],
"explanation": "Walked by 12 months (10 adjusted)"
},
"milestone_type": "adaptive_behavior",
"milestone_age_in_months": {
"value": 12,
"citations": [
41
],
"explanation": "Walked by 12 months (10 adjusted)"
},
"milestone_has_regressed": {
"value": true,
"citations": [
110,
132
],
"explanation": "Developmental regression noted"
},
"regression_start_date_in_months": {
"value": 22,
"citations": [
146
],
"explanation": "Regression onset between 21-23 months"
},
"progressed_after_regression": {
"value": false,
"citations": [
162
],
"explanation": "Autism persisted as of July 2002, no mention of regression reversal."
}
},
{
"milestone_name": {
"value": "single_words",
"citations": [
41
],
"explanation": "Started saying a few single words at around age 17 months (15 adjusted)"
},
"milestone_type": "language",
"milestone_age_in_months": {
"value": 17,
"citations": [
41
],
"explanation": "Reported starting single words around 17 months (15 adjusted)"
},
"milestone_has_regressed": {
"value": true,
"citations": [
99,
114
],
"explanation": "Language appeared delayed at 18 months [99], later engaged in limited verbalizations, mostly single word approximations [114]"
},
"regression_start_date_in_months": {
"value": 22,
"citations": [
146
],
"explanation": "Regression onset between 21-23 months"
},
"progressed_after_regression": {
"value": false,
"citations": [
160
],
"explanation": "Autism persisted as of 9/30/02"
}
}
],
"regression_record": {
"pre_regression_language_level": {
"value": "babbling_single_words",
"citations": [
41
],
"explanation": "Reported developing single words around 17 months prior to regression onset."
},
"pre_regression_social_communication_level": {
"value": "reciprocal_interaction",
"citations": [
54,
63
],
"explanation": "General assessments suggested the child was doing well developmentally prior to noticeable delays."
},
"pre_regression_adaptive_behavior_level": {
"value": "moderate_independence",
"citations": [
41
],
"explanation": "Achieved major gross motor milestones (walking) by 12 months (10 adjusted)"
},
"post_regression_language_level": {
"value": "babbling_single_words",
"citations": [
84,
94
],
"explanation": "Language scores were assessed around 15 month equivalent [84] or 12 month developmental age [94] after regression onset."
},
"post_regression_social_communication_level": {
"value": "basic_engagement",
"citations": [
95
],
"explanation": "Socialization scored at 10 month level on Vineland [95]."
},
"post_regression_adaptive_behavior_level": {
"value": "basic_self_help",
"citations": [
95
],
"explanation": "Daily living skills scored at 12 month level on Vineland [95]."
},
"has_language_loss": {
"value": true,
"citations": [
99,
114
],
"explanation": "Concerns about lack of speech started around 18 months, showing regression in flexible phrase speech [99, 114]."
},
"has_social_loss": {
"value": true,
"citations": [
110,
111
],
"explanation": "Parents reported good social behaviors (joint attention, gestures) no longer happening frequently, and decreased interest in playing with others [110, 111]."
},
"has_adaptive_loss": {
"value": true,
"citations": [
127
],
"explanation": "Overall adaptive behavior assessed as Borderline Impaired range relative to age."
},
"has_repetitive_behaviors": {
"value": true,
"citations": [
126,
148
],
"explanation": "Began demonstrating lining up toys and objects shortly before contact, and repetitive language use was noted [126, 148]."
}
},
"early_vaccination_symptoms": {
"had_autism_features": {
"value": false,
"ongoing": false,
"citations": null,
"explanation": "Autism features/regression began 21-23 months after vaccination, not within 30 days."
},
"had_fever": {
"value": false,
"ongoing": false,
"citations": null
},
"had_speech_loss": {
"value": false,
"ongoing": false,
"citations": null,
"explanation": "Language delays emerged much later (around 18 months)."
},
"had_irritability": {
"value": false,
"ongoing": false,
"citations": null
},
"had_eye_contact_loss": {
"value": false,
"ongoing": false,
"citations": null
},
"had_diarrhea": {
"value": false,
"ongoing": false,
"citations": null
},
"had_seizures": {
"value": false,
"ongoing": false,
"citations": null
},
"had_lethargy": {
"value": false,
"ongoing": false,
"citations": null
},
"had_screaming": {
"value": false,
"ongoing": false,
"citations": null,
"explanation": "Screaming due to frustration noted later [82], not acute post-vaccination."
},
"had_behavioral_changes": {
"value": false,
"ongoing": false,
"citations": null
},
"had_rash": {
"value": false,
"ongoing": false,
"citations": null
},
"had_head_banging": {
"value": false,
"ongoing": false,
"citations": null
},
"had_social_withdrawal": {
"value": false,
"ongoing": false,
"citations": null
},
"had_injection_site_reaction": {
"value": false,
"ongoing": false,
"citations": null
},
"had_balance_loss": {
"value": false,
"ongoing": false,
"citations": null
},
"had_appetite_loss": {
"value": false,
"ongoing": false,
"citations": null
},
"had_staring_spells": {
"value": false,
"ongoing": false,
"citations": null
},
"had_hand_flapping": {
"value": false,
"ongoing": false,
"citations": null
},
"had_toe_walking": {
"value": false,
"ongoing": false,
"citations": null
},
"had_gastrointestinal_problems": {
"value": false,
"ongoing": false,
"citations": null
},
"had_hyperactivity": {
"value": false,
"ongoing": false,
"citations": null
},
"had_ear_infections": {
"value": false,
"ongoing": false,
"citations": null,
"explanation": "Otitis media occurred at 9 months, outside the 30-day window."
},
"had_vomiting": {
"value": false,
"ongoing": false,
"citations": null
},
"had_sleep_problems": {
"value": false,
"ongoing": false,
"citations": null
},
"had_encephalopathy": {
"value": false,
"ongoing": false,
"citations": null
}
},
"diagnosis_record": {
"asd_severity": {
"value": 2,
"citations": [
151
],
"explanation": "Autism Treatment Evaluation Checklist rated subject in the 'moderate' autism category."
},
"diagnosis_name": [
{
"value": "Autism",
"citations": [
21,
150
],
"explanation": "Report conclusion states subject is autistic"
},
{
"value": "Mixed Expressive Receptive Language Disorder",
"citations": [
96
],
"explanation": "Psychologist's Dx on 10/9/00"
},
{
"value": "Pervasive Developmental Disorder (rule out)",
"citations": [
130
],
"explanation": "PDD could not be ruled out with the present evaluation."
}
],
"diagnosing_professional": [
{
"value": "Psychologist",
"citations": [
96,
98
],
"explanation": "Evaluations conducted by psychologists"
},
{
"value": "Autism Trainer",
"citations": [
144
],
"explanation": "Evaluated by an autism trainer"
}
]
},
"intervention_record": {
"interventions": [
{
"value": "speech_therapy",
"citations": [
86,
154
],
"explanation": "Speech therapy strongly recommended [86] and recommended later [154]"
},
{
"value": "occupational_therapy",
"citations": [
143,
154
],
"explanation": "Occupational therapy was recommended [143] and later mentioned in recommendations [154]"
},
{
"value": "aba",
"citations": [
154
],
"explanation": "Intensive early intervention using applied behavioral analysis recommended [154]"
},
{
"value": "social_skills",
"citations": [
131,
131
],
"explanation": "Structured interactions w/typical peers [131] recommended to address social skills."
}
],
"is_intervention_ongoing": {
"value": true,
"citations": [
152,
154
],
"explanation": "Intensive intervention recommended to overcome delays."
},
"has_recovery": {
"value": false,
"citations": [
162
],
"explanation": "Autism persisted as of 15July02."
}
},
"birth_record": {
"was_normal_pre_vaccination": {
"value": true,
"citations": [
33
],
"explanation": "Neurobehavioral assessments were appropriate for age throughout hospitalization, suggesting normal development immediately post-birth and early infancy."
},
"apgar_score": [
{
"value": "8 at one minute",
"citations": [
29
],
"explanation": "Aspar scores were 8 and 9 at one and five minutes, respectively."
},
{
"value": "9 at five minutes",
"citations": [
29
],
"explanation": "Aspar scores were 8 and 9 at one and five minutes, respectively."
}
]
},
"behavior_record": {
"repetitive_behaviors": [
{
"value": true,
"citations": [
126
],
"explanation": "Subject recently began demonstrating lining up toys and objects",
"ongoing": true
}
]
},
"heavy_metal_tests": [
{
"metal_type": "lead",
"value": 16.0,
"unit": "ug/L",
"is_elevated": false,
"citations": [
20
]
},
{
"metal_type": "arsenic",
"value": 60.0,
"unit": "ug/L",
"is_elevated": false,
"citations": [
20
]
},
{
"metal_type": "mercury",
"value": 10.0,
"unit": "ug/L",
"is_elevated": false,
"citations": [
20
]
}
],
"comorbidities": [
{
"value": "other",
"citations": [
16
],
"explanation": "Includes various preexisting conditions like bradycardia neonatal, feeding intolerance, GERD, anemia, otitis media, pharyngitis, thrombocytopenia, and viral infection."
}
],
"environmental_exposures": [
{
"value": "unknown",
"citations": [
45
],
"explanation": "Allegation relates to mercury exposure via vaccines, but no confirmed environmental source matching the schema required types was identified."
}
],
"legal_matter": {
"value": true,
"citations": [
22
],
"explanation": "Report received as part of litigation proceedings."
},
"diagnosis_reporting_delay_reason": null
}
```Metrics
{
"elapsed": 34.612513065338135,
"usage": {
"prompt_tokens": 15393,
"completion_tokens": 12205,
"total_tokens": 27598,
"prompt_tokens_details": {
"cached_tokens": 0
},
"completion_tokens_details": {
"reasoning_tokens": 7969,
"image_tokens": 0
}
}
}