Pure Lsp Set Option

Set / unset a Pure runtime option in the LSP

isOptionSet('X') inside Pure resolves, in the LSP JVM, to Boolean.getBoolean("pure.options.X") — read live on every call (default RuntimeOptions.systemPropertyOptions("pure.options.")). So a Pure option can be flipped at runtime by setting/clearing that system property inside the LSP JVM. The bridge exposes this over HTTP so you don't need to restart the (expensive, ~3-min-boot) engine-scale LSP just to change a flag.

Never curl the bridge; bin/pure-lsp-option (below) uses Python's urllib. See references/lsp-devloop-usage-rules.md.

Endpoints

• POST /set-option {"name": "X"} → System.setProperty("pure.options.X","true") → isOptionSet('X') becomes true.
• POST /unset-option {"name": "X"} → System.clearProperty("pure.options.X") → isOptionSet('X') becomes false.
• Either endpoint also accepts an explicit {"value": true|false}; the path just supplies the default.

Both return {"success": true, "name": "X", "effective": <bool>} where effective is the live isOptionSet value read back immediately after the change — use it to confirm the toggle landed.

Usage

All the HTTP mechanics (building the request body, POSTing to /set-option//unset-option, error handling) are implemented deterministically in bin/pure-lsp-option — run it rather than re-deriving an inline Python call by hand:

pure-lsp-option <set|unset> <NAME> [--value true|false] [--port N]

--port is optional: without it the script resolves $PURE_LSP_PORT, else a running bridge discovered from its sidecar, else 8991. Pass --port <N> explicitly only when several bridges are up and you mean a specific one.

Examples:

pure-lsp-option set   ForceInterpreted                  # bypass mayExecuteLegendTest entirely, even if a backend is up
pure-lsp-option set   PlanLocal                          # plan-gen runs LOCALLY (no longer affects FULL_INTERACTIVE)
pure-lsp-option set   FullInteractiveExec                # FULL_INTERACTIVE model, independent of PlanLocal
pure-lsp-option set   ExecPlan                           # use the plan-gen+execute path at all
pure-lsp-option unset ExecDebug                          # quiet (noDebug) plan-gen

On success it prints the bridge's JSON response line to stdout and exits 0:

{"success": true, "name": "ForceInterpreted", "effective": true}

effective is the live isOptionSet value read back immediately after the change — use it to confirm the toggle landed. Non-zero exit (1 = bad usage, 3 = HTTP/connection error) means the call did not land; the real error is printed to stderr — don't assume the option changed.

The options that matter for execute()/go() routing

These are the flags currently gated in core/pure/protocol/vX_X_X/invocations/execution.pure (legendExecute) and core/pure/router/router_entry.pure (meta::pure::router::execute). Verify against the current source before relying on exact behaviour — they are dev-loop overrides, not long-term protocol:

Notes:

• ForceInterpreted shadows ExecPlan/PlanLocal when set — the whole backend-routing branch is skipped, so it doesn't matter what the other two are set to. Nothing stops you from leaving them set alongside it, just know they have no effect while ForceInterpreted is on.
• PlanLocal is the key to fast Pure iteration: local plan-gen uses the live Pure graph in the LSP session, so a Pure-only edit needs no jar rebuild — only Java execution goes to the backend Server. With PlanLocal unset, the server's own jars decide the plan. It used to also gate FULL_INTERACTIVE/SEMI_INTERACTIVE — that's now the independent FullInteractiveExec flag, which the LSP dev-loop flow sets unconditionally regardless of PlanLocal.
• These are OR-independent system properties; setting one does not clear another. If you want a clean state, explicitly unset the ones you are not using.
• Changing a Pure option requires nothing but the HTTP call — the next go()/execute() reads the new value. (Contrast: editing the legend/setOption handler itself is a Java change to the LSP server and needs a rebuild + restart.)