Cursor Agent Go: practical setup and workflow

Cursor Agent is the terminal coding agent from Cursor, started with cursor-agent in a Go module. This guide is for Go developers who want concrete setup, working-loop, and verification patterns: project instructions, table-test-first changes, go test -race, and multi-agent worktrees. It skips general AI-agent advice and focuses on what breaks or helps in idiomatic Go.

Why Cursor Agent is a practical Go pair programmer

Go’s strengths align with a coding agent that can run the compiler and tests locally. gofmt removes formatting arguments, go vet catches common mistakes, and go test ./... gives a quick result. That means an agent can fix its own syntax and style errors before you ever see a diff. The module and package structure also gives the agent natural boundaries: code in internal/ is not importable outside the module, and exported APIs usually live in small, explicit interfaces.

The risk is that Go’s static types do not capture everything. Implicit interface satisfaction, goroutine ownership, context cancellation, and error wrapping are design decisions the compiler accepts but a reviewer must check. Cursor Agent handles these well only when you write them down as project rules and ask for small, tested changes.

Project instructions that keep Go code idiomatic

Cursor Agent reads project instructions from AGENTS.md at the repo root or from .cursor/rules. Put one short AGENTS.md in version control. It should contain the exact commands a human contributor runs, the folder layout, and Go-specific boundaries. Do not paste a design document; the agent needs commands and constraints, not history. For CLI mechanics such as starting and stopping sessions, see How to use Cursor CLI: a step-by-step guide.

# AGENTS.md for a Go service

## Commands
- Build: `go build ./...`
- Test: `go test ./...`
- Race: `go test -race ./...`
- Lint: `go vet ./...`
- Format: `gofmt -w .` then `goimports -w .`

## Layout
- `cmd/` entrypoints, one per binary.
- `internal/` application code that must not be imported outside this module.
- `internal/store/`, `internal/api/`, `internal/service/` for layers.

## Go rules
- Do not change existing exported interfaces without showing the diff first.
- New code must use context.Context for I/O and respect cancellation.
- Goroutines must have clear ownership and a shutdown path.
- Table tests for new logic; keep test names in the form `TestFunc/Scenario`.
- Always run `gofmt` and `go vet` before finishing.

The commands are deliberately explicit. go build ./... catches package-level compile errors before tests, go test -race catches data races, and go vet catches weird constructs that tests may miss. The layout section keeps the agent from creating a new top-level package or importing internal/ code where it should not. The rules section names the three Go areas that matter most: interfaces, context/goroutines, and table tests. If a repo is larger, split rule files by package under .cursor/rules and reference them from AGENTS.md.

A review-first loop for Go changes

Use a small pull-request loop. Start with a plan, not the implementation. For each task, the agent should list the packages it will touch, the functions or types it will change, and the tests that prove the behavior. Then ask for the smallest edit. After the edit, have it run gofmt -l ., go test ./..., and go vet ./... and paste the output. Review the diff yourself, especially for exported interfaces, new goroutines, and context plumbing. If the diff is large, ask the agent to split it into steps and stop after the first green test run.

Example prompts for typical Go tasks:

• “Add a GetUser method to internal/store. Keep the existing Store interface stable, accept context.Context, return (User, error), and add a table test for missing ID and invalid ID.”
• “Refactor the worker pool in internal/worker so it stops cleanly when the context is canceled. Do not change the public API. Run go test -race ./internal/worker and go vet ./....”
• “Write a benchmark for the JSON encoding in internal/api and report allocations per call before changing the hot path.”
• “Find every log.Fatal call in cmd/ and replace it with an error return so the package can be tested.”
• “Add request validation to this handler and return 400 with a JSON error body. Show the table test first, then implement.”

These prompts work because they name the package, the constraint, and the verification command. When the agent proposes something broader, ask for a step plan and get a green test after each step.

Trustworthy Go changes and the traps to inspect

Cursor Agent is good at repetitive, test-visible Go work:

• generating table tests for existing functions,
• plumbing context.Context through a call chain,
• wrapping errors with fmt.Errorf("%w: %v", ...) without losing the original,
• splitting long functions into unexported helpers,
• writing benchmarks and reporting allocations.

Watch it closely in these Go-specific places:

• Exported interfaces: adding a method to a concrete type can silently change satisfaction of an interface defined elsewhere.
• Goroutine lifecycles: it may start a goroutine without a sync.WaitGroup, done channel, or shutdown path.
• Context cancellation: it may call context.Background() deep in a handler instead of passing the request context.
• Error handling: it may return raw errors and drop the original wrapped error.
• Dependencies: it may add a third-party module when the standard library already has the feature.
• Formatting: it may forget gofmt, so include gofmt -w . in every task and review the diff after.

Verifying Go changes with go test and go vet

Make verification part of the prompt. The minimum Go command set for agent work is:

If the agent writes new logic, require table tests in the existing style. A useful checkpoint is to have the agent output the test names and a one-sentence scenario before implementing, so you can catch missing edge cases early. Then run the tests yourself: the agent should not be the only one confirming a green suite. For changes around concurrency, always require -race and ask the agent to explain how a goroutine starts and stops.

Parallel Go work with AgentVera and git worktrees

For Go work, best tools to run AI coding agents in parallel matters when you run Cursor Agent alongside other terminal agents. Give each agent its own git worktree so parallel changes do not overwrite the same Go files; the automatic code review links findings to file:line, which is useful for spotting interface breakage or unsynchronized goroutine logic. Checkpoints let you undo a bad refactor and replay the turn, and token budgets stop an agent before it rewrites an entire module. This keeps multi-agent Go work reviewable instead of chaotic.

Wrap-up

Cursor Agent can be a solid Go contributor when you treat it like a careful junior engineer: explicit instructions, small diffs, real tests, and a reviewer who watches interfaces and goroutines. Keep AGENTS.md short, make verification part of every prompt, and use separate git worktrees when several agents edit the same module. That practical setup turns the agent from a code generator into a repeatable Go workflow.