Everything should be made as simple as possible, but not simpler.
KISS Sorcar is an open-source general-purpose AI agent for long-horizon tasks and AI discovery. It is a simple, local-first, bring-your-own-key AI agent framework. It runs as a VS Code extension and a browser/mobile web app, and offers a Python client API. Your prompts and code are sent directly to the model provider or local endpoint you configure — not through our servers. It supports multi-model workflows just via prompts. All agents run as daemons. Complex AI systems/techniques can be replaced with a paragraph of prompt in KISS Sorcar.
Preferred way to install KISS Sorcar — macOS & Linux, one command, no extra steps.
A side-by-side look at the differences that matter for everyday use.
| Capability | KISS Sorcar | Claude Code | Cursor |
|---|---|---|---|
| Interfaces | VS Code extension + web/mobile app + Python API | CLI + mobile app | Custom VS Code |
| AI Discovery | ✓ simply via prompt | ✗ | ✗ |
| GEPA Prompt Optimization | ✓ simply via prompt | ✗ | ✗ |
| Multiple models from multiple vendors in the same task | ✓ Mix OpenAI, Anthropic, Gemini, Together, Z.AI, Moonshot AI, OpenRouter, Claude Code CLI, and Codex CLI | ✗ Anthropic Claude models only | ✗ One model per task |
| Primary focus | ✓ Quality — rigorous review, end-to-end tests | Speed and developer ergonomics | Speed |
| Core Agents # LoC | ~3000 | Unknown | Unknown |
| Models in bundled catalog | 622 across 9 provider categories | Claude family only | Subset chosen by Cursor |
| Bring your own API key / endpoint | ✓ Yes — keys stay on your machine | ✓ Anthropic key | ⚠ Routed through Cursor backend |
| Open source | ✓ Apache-2.0 | ✗ Proprietary | ✗ Proprietary |
| Price | Free framework; pay only your chosen model provider | Subscription / API usage | Subscription |
| Run on top of Claude Code / Codex CLI | ✓ cc/* and codex/* namespaces |
N/A | ✗ |
| Messaging and communication channels | ✓ 32 third-party channel agents, including Slack, Gmail, Email (IMAP/SMTP), Phone Control, SMS, WhatsApp, and Home Assistant | ⚠ Slack, mobile Remote Control, and research-preview channels for Telegram, Discord, and iMessage; no documented built-in Gmail, WhatsApp, phone-call, or SMS channel | ⚠ Slack and Microsoft Teams Cloud Agent integrations; no documented built-in Gmail, WhatsApp, phone-call, or SMS channel |
| Scheduled automations | ✓ Natural-language cron agent | ✗ | ✗ |
| Wake word for voice interaction | Sorcar | N/A | N/A |
KISS Sorcar ships with a curated set of sample tasks (long-horizon prompts you can drop straight into the VS Code extension or Web app) and promptlet tricks (short reusable directives that steer Sorcar's behaviour by injecting to the prompt). The tasks live in src/kiss/SAMPLE_TASKS.md; the tricks live in src/kiss/INJECTIONS.md. You can add your tasks at ~/.kiss/MY_TASK_TEMPLATES.md and your promptlets at ~/.kiss/MY_INJECTION.md.
Ask Sorcar to walk you through the detailed step-by-step workflow of any algorithm or feature in your codebase, so you can understand it before changing it.
Can you show me the detailed step-by-step workflow of <<your algorithm or feature>>
Modify a specific step of an existing workflow with a precise natural-language instruction — no need to point Sorcar at the file, it will find the right code.
Can you change the step <<specify step>> as follows: <<whatever way you want to change>>
Have Sorcar log you into a Slack workspace using the bundled Slack agent, so it can send and receive messages on your behalf.
Can you authenticate me with the <<workspace name>> workspace on Slack using the Slack agent?
Spin up a named cron job that polls a Slack channel for the latest unanswered messages, runs them as Sorcar tasks in arrival order, and replies with Slack-formatted results.
Can you create a cron job with a name prefixed with "kiss-" which will check every 3 seconds if there are the latest unanswered messages from /<<user name>> in the channel sorcar using the Slack agent, then it will run the messages as tasks one-by-one in the order of arrival and respond with the result suitably formatted for Slack.
Connect Sorcar to your iMessage account so it can send and receive texts directly from macOS.
Can you authenticate me with the iMessage agent?
Dispatch a one-line SMS to any phone number through Sorcar's messaging agents — no scripting required.
Can you send "Hello from Sorcar!" to 1-800-772-1213?
Walk through the OAuth login flow for Gmail using the bundled Gmail agent, with the browser handling consent and Sorcar storing the token locally.
Can you authenticate me with Gmail using the Gmail agent? Use the user's default browser to prompt the user to log in and obtain the authentication token.
Have Sorcar fact-check a URL for wrong assumptions, cheating, irreproducibility, fraud, AI slop, and security vulnerabilities — verifying every claim and shipping a report.
Can you read <<url>>, and thoroughly and precisely check for **wrong assumptions**, **cheating**, **irreproducibility issues**, **fraud**, **potential for cheating in evaluation**, **AI Slop**, and **security vulnerabilities**? Use the internet extensively and do not believe what people say -- verify it yourself. Do not hesitate to download code and run it to validate results. For security vulnerabilities, create a POC and test it. Create a report.
Let Sorcar search, train, and benchmark candidate models on your data to find the lightest, fastest, cheapest model that hits your target accuracy, recall, and price-per-query.
Sorcar for AI Discovery: Can you AI discover the lightest and fastest AI model that will give the best accuracy and recall on the data at <</path/to/data>> at the cheapest price? Use 'modal' CLI to train your models on GPUs and evaluate if needed. The total budget for Modal.com is $ 1,000. Do not STOP until accuracy/recall reaches 99% and price per query on the model is less than $0.50. Create a report.
Run a command, let Sorcar instrument and monitor its output, then iteratively rewrite the code and apply AI discovery to hit your speed, accuracy, recall, and cost targets.
Sorcar for Optimization: Can you run the command <<command>> and optimize it with respect to the following metrics: <<speed, accuracy, recall, cost>>. Then use AI discovery to optimize. You can add a diagnostic code that prints metrics, such as running time, at a finer granularity. Do not forget to remove the diagnostic code after the optimization is complete. You MUST NOT STOP until the metrics achieve the following values: <<give_concrete_values_for_metrics>>. Create a report.
Run a full GEPA Pareto-frontier prompt-optimization loop over your dataset to evolve the best prompt for a ChatSorcarAgent, with cross-model review and no reward hacking.
Sorcar GEPA Prompt Optimizer: Can you optimize a prompt for a ChatSorcarAgent of the kiss-agent-framework Python library using the following GEPA algorithm on the data at <<url_or_db_file_of_data>> using claude-fable-5? You can find the trajectory events of an agent execution in ~/.kiss/sorcar.db after the agent has finished its execution. Split the dataset into a 50% dev set and a 50% val set. RUN_GEPA: Sample 100 data points from the val set and call it the sval set. Maintain a Pareto frontier in the folder ./pareto, with a sub-folder for each node in the frontier. A node contains a prompt file (prompt.md) and a JSON file, say score.json, containing the list of data points (ids) from the sval set that were correctly predicted by the prompt. When you add a node to the Pareto frontier, make sure that the list of correctly predicted data points is not a subset or equal to an existing list of data points in some node in the frontier. If such a node exists, do not add the new node. After adding a node, remove all nodes whose list of datapoints is a subset or equal to the list of datapoints in the added node. Then run the following algorithm. 1. pick a node from the Pareto frontier with probability 0.5 a. sample a minibatch of 5 datapoints from the dev set b. run the agent with the prompt from the node on the minibatch c. If the agent incorrectly predicts for some datapoints, analyze and reflect on the trajectory events of the agent on those datapoints available at ~/.kiss/sorcar.db and propose a new prompt that will fix the mistakes made by the agent on datapoints incorrectly predicted d. if the agent predicts correctly on the minibatch, then evaluate it on the sval set and create the list of datapoints on which the agent with the new prompt predicts correctly. e. Add the new prompt and the list of datapoints to the Pareto frontier 1. Pick two nodes from the Pareto frontier randomly with the remaining probability. a. Sample a minibatch of 5 datapoints from the dev set b. Merge the prompts from the two nodes into a new prompt. c. If the agent predicts correctly on the minibatch with the new prompt, then evaluate it on the sval set and create the list of datapoints on which the agent with the new prompt predicts correctly. d. Add the new prompt and the list of datapoints to the Pareto frontier 1. Repeat steps 1 and 2 until there is no change in the prompt after 3 iterations. END_RUN_GEPA Repeat RUN_GEPA until there is no change in the prompt after 3 iterations. At each step, keep track of the best prompt, which has the maximum number of successfully predicted data points, in ./pareto/optimal.md. MAKE SURE THAT YOU DO NOT DO REWARD HACKING OR CHEATING IN THE AGENT YOU ARE IMPLEMENTING TO FIT DATA. YOUR SOLUTION MUST GENERALIZE BEYOND THE DATA PROVIDED. Use internet search extensively at every step. Do not worry about budget. Create an HTML report with diagrams and illustrations in ./reports and open it in the user's default browser. Do NOT STOP until you cannot improve the accuracy and recall after three consecutive rollouts. Use gpt-5.6-sol model (not codex) for a thorough review of the work done at every step by the other model.
A one-liner to invoke gepa.py on the HotpotQA dataset with gpt-4o-mini as both the task model and the optimizer.
Can you run gepa.py on hotpotqa using gpt-4o-mini as both models?
Use Claude Fable as the implementer and GPT-5.6 Sol as a read-only reviewer/debugger — capped at 50% of the task budget and told not to invent new problems — so missed code, missing wirings, and silent bugs are caught before they ship.
Use 'claude-fable-5' model for all tasks, including software development. Use 'gpt-5.6-sol' (not codex) for a thorough read-only review and debugging of the other model's work. Thoroughly check whether the other model has missed any code or wiring or introduced any bugs. Use at most 50% of task budget in gpt-5.6-sol for reviewing and debugging, and ask the model to not invent new problems. Use the model names literally without hallucinating new model names.
Codify suspected invariant breaks as end-to-end tests with 100% coverage first, then let Sorcar fix the offending code so the invariant holds forever.
Reproduce any violation of the invariant by writing end-to-end tests with 100% coverage. Then fix the issue.
Point Sorcar at a file of instructions and have it follow them to carry out the task — handy for reusable runbooks and playbooks. Replace @ with the path to your file.
Can you use the instructions in the file @ to perform the task?
Paste the merge-conflict message after this trick and let Sorcar analyse the diff and resolve the conflict for you.
Can you check the following message for a merge conflict and help me fix it?
Have Sorcar drive your default browser with computer use to complete logins and OAuth flows itself, asking for your help only when it is stuck on a login or CAPTCHA.
You MUST use the user's default browser and computer use to authenticate using claude-fable-5 as the model. Do all the steps on user's behalf and ask user's help ONLY if you are stuck on login or captcha.
The same implement-and-review pattern with Kimi K3 as a lower-cost implementer and GPT-5.6 Sol as the read-only reviewer, capped at 50% of the task budget.
Use 'openrouter/moonshotai/kimi-k3' model for all tasks, including software development. Use 'gpt-5.6-sol' (not codex) for a thorough read-only review and debugging of the other model's work. Thoroughly check whether the other model has missed any code or wiring or introduced any bugs. Use at most 50% of task budget in gpt-5.6-sol for reviewing and debugging, and ask the model to not invent new problems. Use the model names literally without hallucinating new model names.
Route each subtask to the best cheap model — following ./ROUTING.md when it exists — and have Sorcar rewrite the routing strategy after every task so token cost falls without degrading quality.
If ./ROUTING.md exists, use the instructions in the file for model routing. Otherwise, use the best model from ~/.kiss/MODEL_INFO.json for various subtasks. Search the internet extensively to figure out which model is best yet cheap for each subtask. Here are some hints, but the internet has better knowledge: claude-fable-5 and openrouter/moonshotai/kimi-k3 — best for SWE work; gpt-5.6-sol — best for reviewing; openrouter/qwen/qwen3.8-max, openrouter/x-ai/grok-4.6, openrouter/z-ai/glm-5.2-max, openrouter/deepseek/deepseek-v4-pro-0813 — for SWE tasks when budget is low; and gpt-5.6-luna and openrouter/deepseek/deepseek-v4-pro-0813 for review when budget is low. Irrespective of whether ./ROUTING.md exists or not, after the task completes, based on your experience in completing the task, create or update the model routing strategy (as text) in ./ROUTING.md that reduces token cost while not degrading the quality of the work.
Read the research behind KISS Sorcar — the system, how it built itself, how it wrote its own paper, and the systems, defenses, and test generators it produced.
Introduces KISS Sorcar and the underlying KISS Agent Framework: a deliberately minimal, open-source agent runtime designed for long-horizon tasks, rigorous review, multi-model orchestration, and AI discovery.
A case study of building KISS Sorcar with KISS Sorcar itself. Over 44 days the developer issued 3,099 tasks through the system's own interface; we analyze the SQLite usage log and surface nine recurring human–AI collaboration patterns.
A nine-day, hundred-task chronicle of KISS Sorcar drafting, citing, compiling, and debugging its own research paper — doubling as a stress test of the agent itself.
A larger-than-memory key-value store in dependency-free C++17 that outperforms Microsoft's FASTER on skewed YCSB-A under a hard memory budget — designed, implemented, and tested almost entirely by KISS Sorcar through natural-language tasks, and verified by independent audits.
A defense against backdoored patches from LLM program-repair agents: a confidence-gated intent-alignment judge with capability-diff reasoning, evaluated on a five-CWE-family corpus and under adaptive attack — with an honestly reported partial-defense result.
Improves LLM-based commit-directed test generation over the Cleverest baseline with a fixed-budget three-model portfolio, sanitizer-signature-grounded oracles, and shell-free execution.
Write-ups of real optimization and discovery runs performed end-to-end by KISS Sorcar, with reproducible numbers.
Rewires the multithreaded file-mode pipeline of lz4 v1.10.0 to reach 1.88–2.57× the throughput of the stock CLI at level -1 (3,810 vs 1,519 MB/s at 32 threads), with compressed output byte-identical to upstream at every tested level. Includes head-to-head runs against pigz, pzstd, and zstd -T. Done in about 7½ hours of agent wall-clock time.
Makes an upstream DuckDB development tree faster on five suites — TPC-H sf1, TPC-DS sf1, IMDB/JOB, h2oai group/join, and ClickBench — with verified geometric-mean speedups of 1.152–1.237× per suite over the stock release build and a largest single-query win of ~1.73×. Three of the five suites were held out from all profile training.
Reconstructs the two benchmark families from Phylo’s Biomni × TusoAI blog — perturbation-response prediction (Replogle, Adamson, Norman) and pgBoost-style enhancer–gene linking — then runs an AI-discovery loop until one evolved method scores at least 99/100 on every task. Code and full protocol at github.com/ksenxx/biomni_tuso.
Speeds up the SQLite 3.54.0 development trunk on speedtest1, kvtest, TATP (OLTP), and the Star Schema Benchmark (OLAP), reaching a verified geometric-mean speedup of 1.59×. Full source published at github.com/ksenxx/sqlite-optimized.
An independent rebuild-and-reproduce audit of the sqlite-optimized repository: builds cleanly from scratch, no code or wiring missing, and the claimed benchmark results reproduce. A companion piece to the SQLite optimization post.
Talks, demos, and case studies on doing real software engineering with KISS Sorcar.
Two names. One principle. A nod to a Bengali magician.
KISS Agent Framework is a deliberately small agent runtime organized around the KISS principle — "Keep it Simple, Stupid."
KISS Sorcar is named after P. C. Sorcar, the legendary Bengali magician, evoking the idea of an agent that performs feats that appear magical yet are grounded in disciplined engineering. Note: Sorcar also means government in Bengali.
Pick the install path that fits you — full source, Python package, or the VS Code extension. All you need is at least one API key from a major LLM provider. The one-line install script below is the recommended way to install the full KISS Sorcar stack.
Preferred way to install the full KISS Sorcar stack. Works on macOS and Linux (x86_64, aarch64, arm64). Installs or checks every tool needed to run KISS Sorcar and build/install the VS Code extension — one command, no extra steps.
For just the Python package — the kiss-web daemon, the Python client API, and the messaging-agent entry points. KISS Sorcar requires Python 3.13+.
Provide at least one model backend through environment variables:
You can also set API keys, a custom model endpoint, and custom HTTP headers in the Settings panel of the VS Code extension or web app — or per task via the Python API’s model_config option.
To install only the KISS Sorcar extension, open Visual Studio Code, search for KISS Sorcar in the extension marketplace, install it, and relaunch VS Code.
Press ESC if you do not have a specific API key ready, but configure at least one model backend before running tasks.
sorcar.run Python API.¶
The kiss-web daemon serves every client — the VS Code sidebar, the remote web/mobile app, and your own Python scripts. Call kiss.server.sorcar.run to launch a task on the daemon and block until it finishes: pick any model with model=, cap spend with max_budget=, continue a chat with chat_id=, and hand the agent your own tools with tools=.
Full reference (the kiss-web daemon, chat-client features, every run() option, skills, and MCP discovery): Full client reference →
KISS Sorcar includes 32 third-party channel agents that act on messaging services, mailboxes, and devices on your behalf, plus two infrastructure agents: an A2A agent (kiss-a2a) exposing Sorcar over the agent-to-agent protocol and an OpenAI-compatible server (kiss-oai) that serves Sorcar behind an OpenAI-style HTTP API. It also ships a Govee smart-home CLI for controlling IoT lights (on/off, brightness, color, and color temperature) via the Govee Developer API. These agents live in src/kiss/agents/third_party_agents/.
A Govee smart-home CLI for controlling IoT lights — on/off, brightness, color, and color temperature — directly via the Govee Developer API.
KISS Sorcar ships a catalog of 622 models across 9 provider categories, with built-in prices, context lengths, and capability flags (fc function calling, gen generation, emb embedding). The source of truth is src/kiss/core/models/MODEL_INFO.json.
cc/*)13codex/*)9Across all bundled providers, the catalog currently reports:
See the full per-provider model list in the README, including the cc/* and codex/* namespaces that let KISS Sorcar run on top of the Claude Code and Codex CLIs.
Contributions in the form of issues are welcome. KISS Sorcar should be able to help implement and review them.
Report bugs, request features, or share ideas. Each issue becomes a candidate task KISS Sorcar can pick up and work on.
Drop an issue link into a Sorcar task and it will draft a fix, run tests, and self-review before opening a PR.
KISS Sorcar is released under a permissive open-source license.
Use it for anything — personal, commercial, research, education. See LICENSE for the full text.
Apache License 2.0If you use KISS Sorcar in your research, please cite:
@misc{sen2026kisssorcar,
title = {KISS Sorcar: A Stupidly-Simple General-Purpose and Software Engineering AI Assistant},
author = {Sen, Koushik},
year = {2026},
eprint = {2604.23822},
archivePrefix = {arXiv},
primaryClass = {cs.SE},
url = {https://arxiv.org/abs/2604.23822}
}