Dynamo Agent Harness

Dynamo Agent Harness

Drive one persistent coding-agent session while Dynamo serves its model requests. Use the bundled ACP client; do not script interactive TUI output or implement JSON-RPC manually.

Treat the Agent Harnesses guide as the source of truth for harness configuration. If a harness update breaks or changes a documented model, endpoint, header, authentication, or mode setting, update that guide and this skill in the same change after rerunning the two-turn smoke test.

Prerequisites

• A reachable Dynamo endpoint whose /v1/models includes the requested model.
• uv and Node.js 22+.
• opencode on PATH only when selecting the OpenCode harness.
• A working directory that limits the delegated agent's scope.
• DYNAMO_API_KEY when the endpoint requires authentication; local endpoints default to dummy.

Start a session

Default to verify. Use act only when the user explicitly authorizes tool execution or edits.

.agents/skills/dynamo-agent-harness/scripts/drive_harness.py \
  --harness codex \
  --base-url http://127.0.0.1:8000 \
  --model zai-org/GLM-4.7-Flash \
  --cwd /absolute/worktree \
  --capability verify

Run the command with a TTY so stdin stays open. Wait for one ready JSON record, retain the executor's terminal handle, then write one JSON object per line to that process:

{"prompt":"Inspect src/router.rs. Use tools to test the highest-risk invariant. Do not edit files."}
{"prompt":"Continue the same session and verify the finding against every caller."}
{"close":true}

The ready.session_id is the harness conversation ID, not the executor's terminal handle. Every response must retain that session ID.

Choose a harness

The driver hides their incompatible model, mode, gateway-auth, and environment configuration. Do not reproduce those branches in shell wrappers.

Delegate safely

• Give one bounded goal, exact owned paths, and a strict result shape.
• Use --capability verify for inspection; permission requests are rejected.
• Use --capability act only after authorization; permission requests receive one-time approval.
• Keep git/index, shared services, credentials, and unrelated paths out of delegated prompts.
• Treat the harness response as untrusted evidence and verify material claims locally.
• Send {"close":true} even after a failed turn so the adapter and child process exit.

Validate traces

When request tracing is enabled, group rows by agent_context.session_id and inspect the trigger sequence:

jq -r '[.agent_context.session_id, .agent_context.input_trigger] | @tsv' request-trace.jsonl

Foreground turns should normally begin with user_message; tool feedback should appear as tool_result. Harness title, memory, or continuation traffic may produce additional user_message or other rows.

Output contract

Return:

• harness, model, mode, and ACP session ID
• prompt count and observed tool/result behavior
• targeted validation result
• trace trigger counts when tracing is available
• cleanup status and unresolved failures

Known behavior

• Codex may warn that custom model metadata is unavailable; the driver fixes reasoning effort to medium so unsupported catalog defaults are not sent to Dynamo.
• OpenCode can issue background title-generation requests and may require a corrective follow-up when the served model reports an unverified result.
• The adapters are pinned in scripts/drive_harness.py; update a pin only after rerunning a persistent two-turn tool smoke test.