
Sub-agents that work in parallel
At the Ultra effort tier Context deploys bounded sub-agents — read-only explorers or full implementers under the same permissions — that work side by side and report back.
Context indexes your repository, reads the current source before every edit, runs your project’s own tests and tells you exactly what it changed. Local-first, with any OpenAI-compatible model.
v0.1.1 · Free and open source · macOS, Windows and the terminal

Context for macOS · v0.1.1
macOS 26 · Apple silicon
Features

A Tree-sitter index, lexical search, a symbol graph, embeddings and memory are fused for every request and checked against the working tree, so each task starts from the files that matter.

Every patch carries the hash of the text it was written against and is refused if the file changed underneath. Each file touched and command run is recorded.

Point it at OpenAI, a gateway, a self-hosted server or a local runtime. ctx doctor --probe checks what the endpoint really supports, and Context relies only on that.
Plan, edit, validate and recover in one tool loop, then review the result in a native app built for it.

At the Ultra effort tier Context deploys bounded sub-agents — read-only explorers or full implementers under the same permissions — that work side by side and report back.

See every diff the agent made in one place. Stage, commit, branch or open a pull request without leaving the app.

Stable policy and tool schemas come first so provider caches hit; old turns are compacted into checkpoints. ctx context explain shows what the model saw and why.

Three permission profiles, a command classifier that looks through pipes and wrappers, path policy with symlink checks, and credential redaction everywhere.

The same runtime runs as a full-screen terminal UI and as headless ctx run with stable exit codes for CI. Sessions and memories follow you between the app and the terminal.
How it works
Every message goes through the same loop: find the work, gather the code, act through checked tools, validate the result, and remember it for next time.
Fig. 1The task loop
The message is matched against active and recent tasks: continue, refine, start new, refer to earlier work or reverse it.
Path, lexical, symbol, semantic and memory strategies run in parallel, are fused by reciprocal rank, expanded along imports and tests, and re-verified against the working tree.
Stable policy and tool schemas first, then the repository summary, the untrusted repository payload inside explicit delimiters, the retained conversation and the request.
read_file, search_code, find_symbol, apply_patch, execute_command, run_validation and MCP tools. Every call is schema-checked, permission-gated and recorded.
Changes are checked with the project’s own validation commands. A failure starts a bounded recovery cycle with fresh retrieval, and the report never claims a test that no tool observed.
Task state, checkpoints, the event log and episodic memory are saved, so later messages and later sessions build on the work instead of replaying it.
Fig. 2At a glance
10
languages indexed with Tree-sitter
5
retrieval strategies fused per request
3
permission profiles, from ask to bypass
1
data directory shared by the app, TUI and CLI
Download
One Rust runtime behind a native Mac app, a Windows app and a terminal UI. Sessions, tasks, the index and memories follow you between them.

macOS 26 Tahoe or later · Apple silicon

Windows 10 or 11 · x64 .exe or .msi

Builds from source · stable Rust 1.85+
ctx init# writes ~/.context-agent/config.tomlctx doctor --probe# checks what your endpoint supportsctx run "Add a loading indicator to the login button"# in your repo: one task, end to endSet your endpoint and key in config.toml, or export OPENAI_API_KEY, before probing.CLI reference
Pricing
Context itself is free. You pay your model provider directly, or sign in to ModelGateway from the app for one account across many models.
$0forever
Apache-2.0 or MIT, at your option.
Pay as you go
Optional. One sign-in for many models, with usage and billing in the app.
The $10 Context credit can be claimed once per ModelGateway account after a completed card or crypto deposit, and only Context’s own requests can spend it.
The index, history, memories and checkpoints live in ~/.context-agent on your machine, shared by the app, the terminal UI and ctx run.
The model endpoint you configure receives the prompts Context assembles for each request: the code the task needs, with credential files kept out and credential patterns redacted. ctx context explain shows exactly what the model saw and why, and with a local runtime those prompts never leave your machine. If the agent searches the web, only the query goes to a search provider, after credential redaction and, under the default Ask profile, your approval.
Any OpenAI-compatible endpoint: OpenAI, a gateway such as ModelGateway, a self-hosted server or a local runtime. ctx doctor --probe checks what the endpoint actually supports (tool calling, streaming, usage reporting and parallel calls), and Context only relies on what the probe verified.
You decide how much it may do without asking. There are three permission profiles:
A conservative classifier looks through pipes, wrappers and command substitutions to decide what needs approval. Under every profile, denied commands are refused, and file tools follow symlinks and refuse credential files and paths outside the workspace. There is no OS-level sandbox, so pick the profile that matches how far you trust the task.
ctx bundled.ctx.exe and runs natively, without WSL; Git for Windows is recommended.ctx; to use the CLI and terminal UI on their own, build from source with stable Rust 1.85 or later.The Mac app checks for a new release once a day, downloads it in the background and installs it, ctx included, the next time you quit. Check for Updates… in the Context menu checks right away, and Settings → General → Updates turns the automatic parts off.
Yes. ctx run works headless: JSON mode prints events on stderr and the outcome on stdout.
$ ctx run --json --approval auto --timeout 600 \
"Fix the failing tests"The exit codes are stable:
Nothing. Context is free and open source, licensed under Apache-2.0 or MIT at your option. You pay your model provider for what you use, or nothing at all with a local runtime. Signing in with ModelGateway from the app is optional and puts usage and billing in one place; after a first deposit, an account can claim a one-time $10 Context credit.

Get started
Download Context, point it at your repository and describe the change. It will tell you what it did — and what it couldn’t verify.
Also for Windows x64 and the terminal · v0.1.1