Codex CLI Provider for GSD2

gsd2-provider-codex-cli adds a Codex CLI-backed provider plugin for GSD using @thereaperjay/gsd-provider-api.

What it does

• Registers provider codex-reaper with model IDs in codex-reaper:* namespace
• Uses codex exec --json for request execution (CLI-authenticated runtime)
• Translates Codex JSONL events into GSD provider events (text_delta, tool_call_*, tool_result, completion, error)
• Injects GSD tool registry into Codex per-run through a local Streamable HTTP MCP bridge (mcp_servers.gsd_tools.url=...)
• Runs onboarding/readiness checks via codex --version and codex login status
• Enforces soft/idle/hard timeout handling from supervisor config
• Applies context-write blocking checks to shell write commands and MCP tool arguments before execution
• Writes JSONL activity logs for assistant/tool events in .gsd/activity

Tool Use Behavior

This provider treats Codex tool-like item events as tool activity:

• item.started (command_execution) -> tool_call_start + tool_call_delta
• item.completed (command_execution) -> tool_call_end + tool_result
• other non-message item types -> generic tool_call_* + tool_result

Tool details are derived from the command string and surfaced to GSD status UI.

To keep tool output cleanly separated from assistant chat content, command/tool result payloads are not forwarded as text_delta.

Token / Usage Mapping

On turn.completed, usage fields map as:

• input_tokens -> usage.inputTokens
• output_tokens -> usage.outputTokens
• cached_input_tokens -> usage.cacheReadTokens

If usage is unavailable, the provider emits completion with 0 token counts.

Auth Check

Onboarding and readiness checks require:

1. codex binary available on PATH
2. codex login status indicates logged in

If either check fails, GSD onboarding reports the corrective instruction.

MCP Tool Bridge

This provider starts an in-process MCP server bound to 127.0.0.1 on an ephemeral port and injects it into Codex with per-run config overrides:

• -c mcp_servers.gsd_tools.url="http://127.0.0.1:<port>/mcp"

The bridge merges:

• tools passed in context.tools from GSD
• globally registered tools from @thereaperjay/gsd-provider-api tool registry

Files

• index.ts - extension entrypoint wiring
• info.ts - provider metadata, auth checks, stream translation runtime
• activity-writer.ts - activity JSONL writer for Codex stream events
• mcp-http-tools.ts - local Streamable HTTP MCP bridge for GSD tools
• extension-manifest.json - extension metadata for GSD