Workspace
Read, edit, grep, glob, semantic search, LSP diagnostics, and notebooks.
→A sharper way to
work with agents.
Arc is a high-performance coding agent that stays inside VS Code. It routes work across models, uses the tools your repository demands, and keeps every change visible.
Trace the checkout regression, fix it, and verify the payment tests.
Called
Searched for payment session callers
Read src/checkout/session.ts
Edited src/checkout/session.ts
Diff
src/checkout/session.ts
-84return createSession(cart);
+84return createSession(cart, idempotencyKey);
Verified payment tests · 12 passed
0.20 MBExtension size
150+Built-in providers
4 tiersModel registry
NativeVS Code workflows
Small footprint.
Serious machinery.
Capability should not require a hundred-megabyte extension or a second place to work. Arc optimizes its dependency tree, leans on native VS Code APIs, and ships the agentic stack in 0.20 MB.
Less extension.
More attention on code.
Arc's tiny extension footprint leaves more room for the code, tools, and models that do the work.
- Arc
- 0.20 MB(Reference size)
- Cline
- 10.18 MB(50.9 times larger than Arc)
- Roo Code
- 30.11 MB(150.6 times larger than Arc)
- Kilo Code
- 102.36 MB(511.8 times larger than Arc)
- Continue
- 111.48 MB(557.4 times larger than Arc)
Hover me
Use the right model.
Not just one model.
Start with a capable default. Arc delegates routine work downward to cheaper models and hands hard problems upward, preserving the plan and conversation as control moves between agents.
- Multi-provider failover
- Weighted load balancing
- BYOK across 150+ providers
- Per-task model and tier pinning
- Lower cost
- FreeLookup and routine tasks
- LightFocused implementation
- DefaultPrimary session ownerActive
- HeavyAmbiguous, difficult work
- Deeper reasoning
Enough context to do the work.
Arc does not stop at text generation. It operates across the same surfaces you use to understand, change, and validate software.
Execution
Shell processes, OS sandboxing, browser automation, and post-edit verification.
→Coordination
Subagents, full handoffs, per-file locks, persistent plans, and session resume.
→Extensibility
MCP tools, resources, prompts, custom skills, rules, modes, and memory.
→Follow the whole process.
A complex task can move through search, language intelligence, execution, delegation, edits, browser checks, and verification without hiding the path it took.
Replace the polling dashboard with a live event stream, preserve reconnect behavior, and verify it in the browser.
Called
Thought for 4.8 seconds
Planned implementation
- ✓Map the polling and reconnect paths
- ✓Implement the event stream hook
- Verify reconnect and rendering behavior
Searched for dashboard polling and reconnect logic
Read src/dashboard/useMetrics.ts
Found references to createPollingClient
Ran dashboard tests
Command
pnpm test dashboard --run
Output
18 passed · 1 failed
Error: reconnect resumes duplicate stream
Error: reconnect resumes duplicate stream
Asked a subagent to inspect stream lifecycle edge cases
Read server event contract
Found stale EventSource retained across retries
Handed off for implementation
Claude Sonnet 5→GPT-5.6 Sol
Preserve the reconnect contract while replacing the transport.
Edited src/dashboard/useMetrics.ts
Diff
src/dashboard/useMetrics.ts
-42const timer = setInterval(refresh, 5000);
+42const stream = connectMetrics({ signal });
+43stream.onmessage = applyMetricEvent;
Checked problems · 0 diagnostics
Verified tests and reconnect behavior in the browser
Trust is a system property.
Agentic work needs more than a permission dialog. Arc makes containment, recovery, and evidence part of the execution path.
Pre-write secret scanning
Keys and tokens are caught before content reaches the filesystem.
Content-addressed checkpoints
Changed files are hashed, deduplicated, restorable, and garbage-collected.
Tamper-evident audit logs
Exported JSONL traces are SHA-256 hash-chained and independently verifiable.
Constrained modes
Per-mode write globs define exactly where an agent is allowed to make changes.
Audit exports are SHA-256 hash-chained and can be checked independently with arc audit verify session.jsonl.
An agent is a tool.
You are still the engineer.
Not a remote replacement for your editor. Arc stays where the code, diagnostics, and diffs already are.
Not an opaque cloud router. Configure providers and keys directly, with granular proxy controls.
Not a terminal hidden behind a GUI. Modes and context are visible controls, not hidden slash commands.
Not another autocomplete engine. Arc focuses on deliberate tasks that you can inspect and review.
Keep the agent close.
Keep control closer.
code --install-extension khrotu.arc-code