Lanser-CLI

Language Server CLI Empowers Language Agents with Process Rewards

Lanser-CLI is a CLI-first orchestration layer that lets coding agents and developers access language server capabilities with deterministic, replayable workflows.

CLI Overview

• lanser def, lanser references, lanser hover, lanser symbols, and lanser diagnostics execute against Pyright to emit deterministic analysis bundles with caching metadata and selector resolution details.
• lanser rename previews rename results with guardrails for dirty worktrees and workspace jail enforcement.
• lanser batch executes multiple orchestrator commands from a JSONL description, writing JSONL responses so agent planners can pipeline definition, reference, diagnostics, or rename stubs.
• lanser schema validate validates JSON payloads against published schema definitions so agents can verify bundles and environment metadata.
• lanser schema validate-batch validates directories of JSON payloads so golden fixtures remain aligned with published schemas during automation.
• lanser schema export writes JSON schema definitions to disk so CI pipelines can vendor deterministic contracts alongside bundle fixtures.
• Pass --trace-file <path> to any command to capture orchestrator metadata and JSON-RPC traffic as JSONL events for replay and auditing.
• lanser trace replay reconstructs recorded operation outputs from a trace log, regenerating the exact JSON envelope produced during the original run.
• lanser trace list enumerates recorded operations with filtering (operation, selector text, exit code, or status) and JSON output so agents can discover replay indexes before reproducing results.
• lanser trace show displays recorded operation metadata so agents can audit payloads before replaying or exporting results, with the same selector and status filtering available for precise targeting.

Tooling

• Pyright 1.1.407 is the primary language server version for development and CI, with compatibility retained for 1.1.406. Supported versions are centralised in lanser.pyright_version and surfaced via the lanser doctor command.

Citation

@article{zhang2025language,
   title   = {Language Server CLI Empowers Language Agents with Process Rewards},
   author  = {Zhang, Yifan and Contributors, Lanser},
   journal = {arXiv preprint arXiv:TBD},
   year    = {2025}
}