Gooo first program

Produce an actual Gooo source edit and its execution/replay records. The compiler generates Go to execute supported bodies. Use a local shell, Git and Go toolchain selection on macOS or Linux; keep the user's existing files, changes and branch.

Run the current tutorial

Run each command from the repository root in the same shell. Stop on a failed command and retain its diagnostic before changing the source or setup.

1. Read the selected checkout. Reuse an existing kimjooyoon/gooo-go-ports checkout, or obtain a reviewed revision in a new task directory. Read its AGENTS.md, examples/learn-gooo/README.md, both .gooo files in that directory and learn-gooo.workspace.json. Follow that checkout's pins. The example imports Clamp and InRange from limits.gooo into main.gooo.

2. Set up the matching compiler. This current-source workflow targets Go 1.27.3. Bootstrap may download Go and the pinned compiler source, then build the compiler:

   export GOTOOLCHAIN=go1.27.3
   export GOWORK=off
   ./tools/bootstrap.sh

   If a matching compiler is already available, validate its version --build --json record using this checkout's tools/bootstrap-check.go before skipping bootstrap. Substitute that executable's absolute path for ./.gooo below. Selecting Go alone does not establish a matching compiler. Keep the user's global agent settings unchanged.

3. Save the original execution in a fresh directory.

   gooo_trial_dir="$(mktemp -d "${TMPDIR:-/tmp}/gooo-first-program.XXXXXX")"
   ./.gooo version --build --json > "$gooo_trial_dir/compiler-build.json"
   ./.gooo package execute --json --inputs examples/learn-gooo/inputs.json \
     learn-gooo.workspace.json > "$gooo_trial_dir/before.json"

   Inspect result.runtime.traces[].deliveries[].actual. The supplied score 75 returns score: 75, remaining: 25, in_range: true and label: "sensor: high". A declaration check or saved generated Go is not an execution.

4. Make the requested source change. For the first tutorial edit, replace the single if score >= 60 condition in examples/learn-gooo/main.gooo with if score >= 80. Keep the four input rows unchanged. Use the user's requested change instead if they specified one.

5. Execute the edit and replay that new record.

   ./.gooo package execute --json --inputs examples/learn-gooo/inputs.json \
     learn-gooo.workspace.json > "$gooo_trial_dir/after.json"
   ./.gooo package replay --json --receipt "$gooo_trial_dir/after.json" \
     --inputs examples/learn-gooo/inputs.json learn-gooo.workspace.json \
     > "$gooo_trial_dir/replay.json"

   For the supplied edit, score 75 changes to sensor: low; its other three fields and the other three supplied examples stay unchanged. Inspect the actual result. Keep the original record; it is not replay evidence for an edit.

6. Compare and report the saved result. For this exact threshold-60 to threshold-80 edit and the four supplied inputs, a checkout containing cmd/check-tutorial-change can check the three records together:

   go run ./cmd/check-tutorial-change \
     --before "$gooo_trial_dir/before.json" \
     --after "$gooo_trial_dir/after.json" \
     --replay "$gooo_trial_dir/replay.json" \
     --compiler-build "$gooo_trial_dir/compiler-build.json" \
     > "$gooo_trial_dir/comparison.json"

   The comparison checks typed fields, source digests, compiler identity and the edited replay's parent. It does not capture Git revision or support other source edits/input sets; for those, inspect the actual records directly. Report what ran, the source change, observed four-field results, compiler identity and paths of the retained records. Preserve the first failure instead of calling an incomplete attempt successful.

Interpretation and limits

Input-only records report OBSERVED: finite execution observations, not independent expected-output verification or a proof for all inputs. The saved comparison is an unsigned consistency check, not execution authentication.

This example uses signed 64-bit integers and limits Text inputs and each returned Text field to 1,024 UTF-8 bytes. Adding the label suffix can exceed the output limit even when the input fits. Preserve the requested domain; do not truncate values or replace Gooo behavior with handwritten Go.

The browser tutorial runs a fixed compiled program. Use native execution to verify a source edit. For work beyond this example, read the checkout's language and porting guides before promising support. The fixed API-policy Action cannot load this edited tutorial or arbitrary policies. These records authorize no live API effects.

Other starting points

Read only the guidance needed for the actual task:

• Reproduce the older snapshot: use the archived installation procedure for e1e279a, compiler 83928fa, Go 1.27.2 and the matching v0.6.32-dev archive. Verify its checksum and build identity using that snapshot's validator. It is a separate reproduction, not a Go 1.27.3 compiler.
• Diagnose an already configured optional ADK failure: if gooo_discover_capability reports SOURCE_LOWER_FAILED without a useful location, follow the single diagnostic-only check. Preserve the original failure and source; this does not resume execution or change the checkout's pin.
• Try API automation after the tutorial: the cooldown-facts trial has its own pinned setup. Keep this tutorial and its receipts; cooldown facts do not authorize retries.