Tool Use / Function Calling Engineer Salary.
Across 81 U.S. cities.
$133,000
national median salary
$103,000 to $169,000. Last updated August 2026.
Government benchmark for this occupation
The US Bureau of Labor Statistics reports a median annual wage of $135,980 for Software Developers (SOC 15-1252) across the United States, based on 1,687,890 employed workers (May 2025 release).
10th percentile
$82,460
25th percentile
$105,210
Median
$135,980
75th percentile
$171,980
90th percentile
$214,670
Workers surveyed
1,687,890
What BLS published in each release
May 2024 release
$133,080
May 2025 release
$135,980
These are two separate published estimates, not a time series. The Bureau of Labor Statistics does not encourage the use of OEWS data for time-series analysis. Differences between releases reflect changes in occupational classification, survey methodology, and the three-year pooled sample as well as any change in pay, so the two figures should not be read as a rate of wage growth.
BLS publishes wages by occupation code, not by job title, so this figure covers every role mapped to Software Developers (SOC 15-1252) rather than Tool Use / Function Calling Engineerspecifically. The national range at the top of this page is Orbyt’s role-level estimate, which is a different thing and is labelled as such.
View the BLS source for SOC 15-1252Highest Paying
$185,000
San Jose, CA
Best Purchasing Power
$139,000
Richmond, VA
Lowest Paying
$102,000
Charleston, WV
The salary figures on this page are computed estimates, not observed wages. Each one is a national role baseline scaled by a Bureau of Economic Analysis Regional Price Parity cost-of-living multiplier (2025 index) and rounded to the nearest $1,000. No published wage percentile is consulted and no wage survey response enters the calculation, so an Orbyt estimate must not be cited as a Bureau of Labor Statistics figure or as measured pay. The published wage data Orbyt holds is Bureau of Labor Statistics Occupational Employment and Wage Statistics, and Department of Labor H-1B Labor Condition Application filings, which record a filed minimum visa base wage rather than market pay. Where BLS publishes a wage for the occupation a role maps to, it is shown on that role's page as a separate benchmark, labelled with its occupation code, metro area and the number of employed workers it covers. Last updated August 2026. This role maps to BLS occupation code 15-1252. Full methodology.
Orbyt estimates the average Tool Use / Function Calling Engineer salary in the United States at $133,000 in 2026, within a range of $103,000 to $169,000. These figures are Orbyt estimates, computed rather than measured, and must not be cited as Bureau of Labor Statistics figures; the published BLS wage for the occupation this role maps to is shown separately on this page. San Jose is the highest of the 81 cities at $185,000, while Richmond offers the best purchasing power after cost-of-living adjustments. Compensation scales with the complexity and reliability of tool integration systems built.
Tool Use / Function Calling Engineer salary by city.
Skills that increase Tool Use / Function Calling Engineer pay.
The skills below command measurable salary premiums for Tool Use / Function Calling Engineers based on job posting data. Learning the top skill here could add $18,620 to your annual compensation.
≈ +$18,620 per year
≈ +$17,290 per year
≈ +$15,960 per year
≈ +$14,630 per year
≈ +$14,630 per year
≈ +$13,300 per year
≈ +$13,300 per year
≈ +$11,970 per year
What you should know.
Compensation scales with the complexity and reliability of tool integration systems built. Engineers who can design robust function calling frameworks with error recovery and multi-step planning earn premiums. Experience with multiple LLM providers and enterprise API ecosystems drives salaries 10% to 18% above median.
Junior tool integration engineers start near $138,000 building basic function schemas. Mid-level engineers designing robust multi-tool orchestration earn $183,000 to $210,000. Principal engineers architecting enterprise tool-use platforms reach $242,000 to $290,000.
Equity at AI platform companies is a significant compensation component. Performance bonuses of 12% to 18% are standard, with some roles offering developer ecosystem growth bonuses tied to platform adoption metrics.
Total compensation breakdown.
Salary by company size
Remote salary adjustment
Remote Tool Use / Function Calling Engineers typically earn $120,000 (10% less than on-site). This reflects location-adjusted pay policies at companies using geographic salary bands. Some companies pay flat national rates regardless of location.
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Common questions about Tool Use / Function Calling Engineer pay.
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