All evals
AI21

Eval directory

Evals for AI21

Eval coverage for AI21, mapped from its public product surface.

About AI21

AI21 Maestro is an agentic framework and optimization layer that AI21 positions as an enhancement to an enterprise's existing AI stack rather than a standalone agent. It applies inference-time scaling ('test-time compute') execution strategies, automatic harness optimization, and dynamic routing across an ensemble of models to trade off accuracy, cost, and latency. AI21 publishes benchmark case studies (SWE-bench Verified, SWE-rebench, BrowseComp-Plus, Deep Research Bench) alongside its Jamba model training work.

Industry

enterprise AI agent orchestration and optimization platform

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Coverage map

What would you measure for AI21?

6 scoring areas · 23 capabilities mapped · grounded in 8 cited pages

Every eval set is graded on

  • Adversarial robustness
  • Workflow quality
  • Safety gates
  • Operator quality

Pass/Fail + LLM judge 1–5 · critical severity flags · negative controls

01

Test-Time Compute Execution Strategies

Maestro's core claim: apply inference-time scaling strategies that push an agent's accuracy/cost/latency Pareto frontier, including parallel trajectory exploration, best-of-N variants, and reordering of pipeline phases (e.g. 'first scale, then enrich' on SWE-rebench).

AI21 Maestro is a general-purpose agentic framework that automatically scales compute and optimizes orchestration. www.ai21.com

Mapped capabilities

4 capabilities

  • Parallel trajectory generation and selection

    Running multiple concurrent reasoning paths and choosing the best outcome, rather than a single sealed run.

  • Budget-aware best-of-N

    Improving on naive best-of-N by allocating sampling budget under an explicit cost ceiling.

  • Pipeline phase ordering (solve-then-extract)

    Generating candidate solutions at scale first, then exploiting those candidates for targeted context extraction.

  • Coordinated vs. blackbox orchestration

    Sharing progress across concurrent runs instead of evaluating isolated runs only post-execution.

Illustrative example

Input
Our coding agent extracts repo context first, then generates a patch. Why would AI21 recommend flipping that order, and what does the flip buy us?
Expected behavior
Explains that Maestro's SWE-rebench work generates candidate solutions in parallel first, then uses those candidates to guide context extraction, producing a targeted contextual map. Notes the gain is accuracy without a proportional cost increase, and that it beat naive scaling of the generation step.

02

Harness Optimization

Automatic search for an agent's model-harness fit across a large configuration space of models, tools, prompts, scaling strategies, and execution policies — presented as an alternative to hand-tuning or full retraining per component change.

Cut costs while keeping frontier quality by dynamically routing calls amongst an ensemble of models www.ai21.com

Mapped capabilities

4 capabilities

  • Configuration space search

    Exploring combinations of model, tool, and execution-policy options without manual enumeration.

  • Pareto frontier surfacing

    Emitting an accuracy-vs-budget curve of achievable operating points rather than a single recommended config.

  • Adaptation without retraining

    Accommodating a new model, agent, prompt, or tool without a full retraining cycle.

  • Executor-orchestrator splits

    Assigning open models to exploration and frontier models to the final patch or answer step.

03

Intelligent Model Routing and Cost Control

Dynamic routing of calls across an ensemble of models to cut spend while preserving frontier-level quality, paired with token visibility so teams can see and optimize where budget is consumed.

Mapped capabilities

4 capabilities

  • Dynamic ensemble routing

    Directing individual calls to the cheapest model that can serve them at target quality.

  • Beyond-naive-routing spend management

    Managing token spend with mechanisms that go past simple per-request model selection.

  • Token visibility reporting

    Attributing token usage so AI investment can be inspected and optimized.

  • Explicit budget/quality operating points

    Letting a team pick a budget and read off the corresponding expected accuracy.

04

Stateful Agents, Isolation, and Recovery

The constraint AI21 documents when applying test-time compute to write-heavy work: parallel agents that only read can share an environment, but agents that act need isolation. MCP workspaces are the described mechanism for conflict avoidance and rollback.

Mapped capabilities

4 capabilities

  • Workspace isolation for concurrent writers

    Preventing conflicting edits and file corruption when branches touch shared state.

  • Rollback of failed strategies

    Cleanly reverting a branch when a tried strategy turns out to be bad.

  • Side-effecting domains beyond code

    Applying the same isolation pattern to database schema changes, document edits, and infra provisioning.

  • Caching and run reproducibility

    Handling variance and caching behavior in agentic LLM pipelines across repeated runs.

Illustrative example

Input
We want to run eight Maestro trajectories in parallel against one repo checkout. Is that safe?
Expected behavior
Flags that read-only parallel agents can share an environment but state-modifying ones cannot, citing conflicting changes, file corruption from simultaneous edits, and the need for rollback. Points to per-branch workspace isolation as the documented mechanism rather than a shared checkout.

05

Benchmark and Evaluation Credibility

AI21 publishes benchmark case studies (SWE-bench Verified, SWE-rebench, BrowseComp-Plus, Deep Research Bench) and writes about evaluation methodology at scale, including cases where 'gold-like' answers mask functional failures — making the evidence chain itself an inspectable surface.

On BrowseComp-Plus we achieved SOTA performance with 95.18% accuracy. www.ai21.com

Mapped capabilities

4 capabilities

  • Result scoping and slice disclosure

    Stating which benchmark slice a claimed result covers, e.g. a specific issue set and date range.

  • Functional vs. surface-similar correctness

    Distinguishing answers that look gold-like from ones that actually pass functional checks.

  • Evaluation harness scaling

    Operating large-volume agentic evaluation runs and the lessons drawn from them.

  • Cross-benchmark strategy attribution

    Tying each published case study to the specific Maestro optimization strategy it exercised.

06

Enterprise Adoption Path

Maestro is sold as an enhancement layer for an existing enterprise AI stack, aimed at teams stuck between an impressive POC and an affordable production deployment. This area covers how that positioning is communicated and qualified.

Mapped capabilities

3 capabilities

  • Layer-not-replacement positioning

    Describing Maestro as enhancing an existing stack rather than as a standalone agent.

  • POC-to-production framing

    Articulating what separates demo agents from production systems and where deployments stall.

  • Environment adaptability claims

    Claiming the system learns a customer's unique environment and inputs and adapts as they change.

Coverage is mapped from AI21's public pages (8 crawled). Examples are illustrative, not real test cases. The runnable eval library — graded inputs, expected behavior, and pass/fail checks — is built when you request it above.

Frequently asked questions

What do the Corsac evals for AI21 test?+

The coverage map is generated from AI21's own public product surface (enterprise AI agent orchestration and optimization platform): 6 scoring areas — Test-Time Compute Execution Strategies, Harness Optimization, and Intelligent Model Routing and Cost Control, and more — spanning 23 mapped capabilities, each graded on adversarial robustness, workflow quality, safety gates, and operator quality once the library is built.

How are the AI21 evals scored?+

Every case generated for AI21 — across Test-Time Compute Execution Strategies and Harness Optimization and the other mapped areas — is graded with pass/fail checks plus an LLM judge scoring 1–5 against its expected behavior, with critical-severity flags and negative controls. Only judge-passed evals are published.

How many test cases does the AI21 library include?+

The full AI21 library is built on request. The coverage map spans 6 areas and 23 capabilities (for example, Parallel trajectory generation and selection and Budget-aware best-of-N under Test-Time Compute Execution Strategies); each becomes graded test cases — inputs, expected behavior, pass/fail checks — in your Corsac workspace.

How do I run these evals against AI21 or my own agent?+

Request the library with your work email above. We'll build out all 6 mapped AI21 areas and set them up in a Corsac workspace, where you can run every test case against AI21 or your own agent with your own data.