WorkBench

July 1, 2026 · View on GitHub

WorkBench Revisited (2026)

WorkBench Revisited re-evaluates 24 models released between 2023 and 2026.

Outcome composition by model

Outcome composition by model. Each model's 690 WorkBench tasks split into correct, failed-but-harmless, and harmful side effect, ordered by task completion. GPT-4 is the original 2024 result; the others are 2026 runs.

The best agent on WorkBench in March 2024, GPT-4, completed 43% of tasks and took an unintended harmful action on 26% of them. In June 2026 the best agent, Claude Fable 5, completes 98% and takes a harmful action on just 1.9%. Three things stand out:

Capability and safety have improved together rather than trade off. On Workbench, the models that finish the most tasks also do the least unintended damage.
Basic mistakes persist. Several classes of error have been eliminated, but frontier models still occasionally cause irreversible harm, such as sending an email to the wrong person.
Open-weight models have collapsed costs for a performance level that was previously only accessible to proprietary models, while frontier costs have stayed relatively stable.

The 2026 release also includes data and code quality improvements, new model scores, and analysis of agent progress since 2024. Read the full write-up in retro/main.pdf.

All 2026 per-task results are committed under data/results/ (gzipped CSVs plus _meta.json sidecars), and every figure in retro/figs/ reads its numbers from retro/data/model_results.json, which scripts/evals/generate_results_summary.py derives from those results via the same scoring pipeline as workbench-evaluate. No correctness or safety number is hand-maintained; the dollar costs in the cost figure are estimated from run traces by scripts/evals/estimate_model_costs.py (traces are not committed for size reasons).

About WorkBench

WorkBench - the first open-source benchmark for evaluating agent performance on realistic workplace tasks. Created by MindsDB. Special thanks to Jorge Torres, Adam Carrigan, and the rest of the MindsDB team for their support. Check out the paper here - https://arxiv.org/abs/2405.00823

WorkBench full pipeline

Figure 1: The WorkBench pipeline. Tasks are generated from templates over five sandbox databases, executed by an agent with 26 read/write tools, and graded by comparing the sandbox's final state against the ground truth.

Installation

Requires Python 3.12+ and uv.

git clone https://github.com/olly-styles/WorkBench.git
cd WorkBench
uv sync --frozen

Usage

All five sandbox databases, task-outcome pairs, and pre-computed inference results are provided in the data directory. Three console scripts are registered by pyproject.toml and can be invoked via uv run:

Script	Purpose
`workbench-evaluate`	Compute metrics over existing results in `data/results/`
`workbench-inference`	Run a model against a task file and write a fresh results CSV
`workbench-generate-data`	Regenerate sandbox databases and task/outcome pairs from scratch

Batch and analysis scripts (multi-model inference runs, cost estimates, plotting) live in scripts/.

Evaluation

All pre-computed inference results are committed under data/results/, so the evaluation numbers in the paper can be reproduced without running inference.

uv run workbench-evaluate
uv run workbench-evaluate --all_tools

Note that results are not provided for the all_tools variant of GPT3.5 and LLama2-70B as the prompt does not fit into the context window for these models.

Ground truth is versioned: the original March 2024 runs are scored against the pre-correction snapshot in data/processed/tasks_and_outcomes/v1/, while current runs use the top-level data/processed/tasks_and_outcomes/ files (v2, which include the 2026 ground-truth corrections). workbench-evaluate picks the right version per results file from the ground_truth_version field in its _meta.json sidecar; runs without a sidecar predate the corrections and default to v1. This keeps published numbers reproducible after ground-truth fixes.

Data generation

All generated data is committed under data/. Regenerating overwrites the committed files, so the command requires --force:

uv run workbench-generate-data --force

This regenerates the five sandbox databases (data/processed/*.csv) and the per-domain task/outcome files (data/processed/tasks_and_outcomes/*.csv).

Inference

Pre-computed inference results are provided in the data directory. To run inference yourself, you need an OpenRouter API key. All LLM calls use the OpenAI-compatible chat-completions API, so no provider-specific SDKs are required.

Create a .env file in the project root:

OPENROUTER_API_KEY=your-openrouter-key
# Optional — direct-provider keys. When present, a model's native provider is
# used directly so calls bill that vendor's credits instead of OpenRouter.
OPENAI_API_KEY=your-openai-key
ANTHROPIC_API_KEY=your-anthropic-key
GEMINI_API_KEY=your-google-key

Routing. Each model has a native provider (OpenAI, Anthropic, Google, or OpenRouter). If that provider's direct key is set, the call goes straight to the vendor (api.openai.com, api.anthropic.com, Gemini's OpenAI-compatible endpoint) and bills its credits; otherwise it falls back to OpenRouter with OPENROUTER_API_KEY. OpenRouter-only models (Qwen, Llama, Mixtral) always use OpenRouter. The chosen route is logged at the start of each run and recorded in the run's _meta.json (provider, base_url, model_id).

Run inference for a specific model and task file

uv run workbench-inference \
    --model_name claude-sonnet-4.6 \
    --tasks_path data/processed/tasks_and_outcomes/email_tasks_and_outcomes.csv

Useful flags:

--tool_selection {all,domains} — pass every tool to the model on every task (all, default) or only the tools relevant to the task's domain (domains).
--workers N — number of parallel workers; tasks are dispatched via a thread pool, with per-thread sandbox state.
--structured_outputs — use the model's native tool-calling API instead of ReAct text parsing.
--act_without_confirmation — append a system-prompt suffix telling the model to act without asking the user to confirm.
--log_traces — also write the full per-task LLM trace as JSON alongside the results CSV.
--resume — resume the most recent matching run: keep rows with an empty error and only re-run missing or errored tasks.

The available model names are the keys of MODEL_REGISTRY in src/evals/agent.py. Current entries include claude-fable-5, gpt-5.4, gpt-5-nano, claude-sonnet-4.6, gemini-3-flash, gemini-2.5-flash, gemini-3.1-flash-lite, qwen-3.5-flash, deepseek-v4-pro, mistral-small-2603, mistral-medium-3-5, plus the original-paper models (gpt-4, gpt-3.5, claude-2, llama2-70b, mixtral-8x7b).

Run inference for all domains and models

uv run scripts/inference/generate_all_results.py

Run inference for a new agent

The agent layer was rewritten to call OpenRouter directly (no LangChain). To experiment with a new agent there are three entry points, all in src/evals/agent.py:

Different prompt, same agent — edit PREFIX, SUFFIX, or ACT_WITHOUT_CONFIRMATION_SUFFIX, or change build_system_prompt.
New model — add an entry to MODEL_REGISTRY mapping a friendly name to a ModelConfig(model_id, supports_temperature, provider) whose model_id is the OpenRouter slug (e.g. openai/...) and whose provider is openai, anthropic, google, or openrouter. Direct providers strip the slug prefix automatically; see "Routing" above.
A different agent loop entirely — implement an alternative to run_agent (ReAct text parsing) or run_agent_structured (native tool calling) and dispatch to it from src/evals/inference.py:_run_single_task.

Development

Install pre-commit hooks to run linting, formatting, type checking, and tests automatically before each commit:

uv run pre-commit install