EONYX Headless Mode: Running the Agent Without the TUI

EONYX also runs headless: it does the task and exits.
That is what scripts, pipes and CI need.
Predictable output, JSON events, meaningful exit codes.

1 ▶️ Running it

1.1 The run subcommand

eonyx run "describe what this repository does"
eonyx run -m deepseek-v4-pro --yolo "fix the failing test"

The prompt comes from the arguments or from stdin.
The argument wins.
If it is given, stdin is never read.
So when you pipe, do not repeat the prompt as an argument:

eonyx run "explain the error in the log"                  # prompt from the argument
{ echo "explain the error:"; cat error.log; } | eonyx run # prompt from stdin

Flags: -m/--model, -s/--session <id>, -c/--continue, --yolo, --json, --system-prompt.

1.2 stdout versus stderr

In text mode the streams are separated.
That makes the output easy to pipe.

• stdout — only the model’s final answer, streamed.
• stderr — reasoning, tool activity (→ name, ← result) and the summary line \n[tokens: N in, M out] [session: <id>].

So redirecting the result is safe:

eonyx run "generate a README from the code" > README.draft.md

1.3 Sessions

Headless runs are saved too.
The conversation can be continued.

eonyx run "start refactoring the parser"   # creates a session
eonyx run -c "now add tests"               # continues the most recent one
eonyx sessions                             # list: id, date, message count

2 🤖 For CI and scripts

2.1 –json mode

--json prints NDJSON to stdout, one JSON record per line.
Easy to parse in a pipeline.

eonyx run --json "fix the test" | jq -c 'select(.type=="tool_end")'

Event types: text, reasoning, tool_start (name, input), tool_end (name, result, is_error).
The final result carries text, input_tokens, output_tokens, cached_tokens and session.

2.2 Exit codes

CI has to tell outcomes apart.
So the codes mean something:

eonyx run --yolo "run the linter and fix the findings" || echo "exit $?"

2.3 A CI example

#!/usr/bin/env bash
set -euo pipefail
export DEEPSEEK_API_KEY="$CI_LLM_KEY"

eonyx run --yolo --json "run go test ./... and fix the failing tests" \
  | tee agent.log \
  | jq -r 'select(.type=="result") | .text'

3 📋 Summary