Interactive REPL

Spall includes an embedded REPL shell that keeps the registry resident in memory and lets you issue multiple commands without the ~50-200ms spec-load overhead on each call.

Starting the REPL

spall repl

spall REPL — type 'help' for commands, 'quit' or 'exit' to leave.
spall> 

Commands Inside the REPL

Any input that is not a special command is parsed as a normal spall command (without the spall prefix):

spall> api list
Registered APIs:
  petstore             https://petstore.swagger.io/v2/swagger.json

spall> petstore get-pet-by-id 1
{ ... }

spall> petstore get-pet-by-id 1 --spall-output csv
id,name,status
1,Rex,available

Special Commands

Ctrl-C interrupts the current prompt without exiting. Ctrl-D sends EOF and exits.

REPL History

Command history is saved to ~/.cache/spall/repl_history (or your platform equivalent) across sessions. Use the Up arrow to recall previous inputs.

When to Use It

The REPL is useful for:

• Interactive API exploration — tab-like speed without tab-like setup.
• Poking at an API while debugging — no repeated spec fetches.
• Batch scripting small exploratory sequences without shell function wrappers.

Request Chaining

The REPL supports pipe syntax to chain requests, passing the JSON response from one stage into the next via JMESPath expressions:

spall> petstore get-pet-by-id 1 | update-pet --id id --status status

Each stage after the first is a chain expression: operation --arg jmespath_expr .... The response from stage N-1 becomes the input for stage N.

If a pipe stage fails, the REPL prints a structured error showing the stage number, the failing expression, and a debug suggestion.

Limitations

• The REPL uses rustyline for line editing. Complex multi-line JSON payloads should be written to a file and passed with @file.
• OAuth2 PKCE interactive flows are not yet implemented inside the REPL.

Next Steps

• CLI Reference
• Request History