# Pixir Harness Open Beta Developer Preview
Date: 2026-06-09
Pixir Harness is available as an early developer preview. This note records the public
preview scope for source installs and the narrow Hex CLI/ACP distribution path. It does
not define a stable Elixir library contract.
## 0.1.4 Runtime Truth And Fanout Honesty Update
Pixir 0.1.4 keeps the same CLI/ACP-only Hex contract and tightens backend
evidence for terminal Turn and Subagent outcomes:
- terminal Turn failures are persisted as durable evidence instead of being
collapsed into clean completion;
- `wait_agent` reports structured partial outcomes when only some children finish;
- Subagent terminal evidence, stale fanout diagnostics, and runtime-truth gauntlets
make bounded fanout easier to audit;
- ADR 0026 documents the runtime terminal-state and replay contract now exposed in
HexDocs.
This release does not claim a complete scheduler, WorkflowRun runtime, production
SLA, SAAAS surface, or performance superiority.
## 0.1.3 ACP Registry Readiness Update
Pixir 0.1.3 keeps the same CLI/ACP-only Hex contract and adds the pieces needed for
public ACP Registry validation:
- ACP `initialize` now advertises terminal authentication through `pixir login`, while
Pixir still owns OAuth and credential storage outside the ACP stdio channel.
- ACP message projection and diagnostics preserve partial assistant evidence more
honestly when Provider streams end unexpectedly.
- Turn, CLI, Subagent, `wait_agent`, and diagnostics hardening now make fanout failures
and timeouts visible as terminal evidence instead of clean completion.
- Source checkouts include `mix pixir.bench.fanout_gauntlet`, a no-network correctness
gauntlet for direct CLI fanout and parent-led Subagent fanout. It is evidence for
outcome honesty, not a public performance benchmark.
- Source checkouts include the repo-local `bin/diagnose-t3-pixir-projection` helper for
comparing Pixir Log truth, T3 provider logs, and T3 projection storage when a
response is not visible where expected. It is not part of the Hex package surface.
- CI is split into clearer Pixir check gates and the projection diagnostic tests can run
with `uv` or a plain Python runner.
This release is the intended Hex base for the public `npx` ACP Registry wrapper.
## 0.1.1 Runtime Diagnostics Update
Pixir 0.1.1 keeps the same CLI/ACP-only Hex contract and adds local Session diagnostic
surfaces for operators:
- `pixir inspect-replay <session-id> --json` inspects replay continuity from the local
Log.
- `pixir diagnose session <session-id> --json` emits a structured Session diagnostic
verdict for replay, lifecycle, and local evidence review.
- Replay folding now tolerates transparent lifecycle/status Events between matched
`tool_call` and `tool_result` records.
- The escript SIGINT path no longer depends on `Mix.env/0` at runtime.
The repo-local Codex/Pixir operator Skills are intentionally not part of the Hex
package. They remain workflow guidance for this repository, not a public Pixir package
contract.
This is not a stable ecosystem release. The goal is to let early users install Pixir,
run `doctor`, try a first terminal or ACP-driven turn, and report the first
installation, auth, model, and workflow failures with useful evidence.
## What Is Supported
- Source install from `https://github.com/Ranvier-Technologies/pixir-harness`.
- Hex escript installation when the `pixir` package is available, scoped to the same
CLI/ACP runtime.
- Terminal CLI through the installed `pixir` escript or a source-built `./pixir`.
- ChatGPT subscription login through `pixir login`, with `OPENAI_API_KEY` as a fallback.
- Local append-only Session Logs under `.pixir/sessions/`.
- `pixir doctor --json` as the first no-network diagnostic gate.
- ACP over stdio through `pixir acp`.
- Agent Skills, Subagents, Workflows, Session tree inspection, and durable compaction
checkpoints.
- Durable Provider usage accounting for token/cache evidence.
- Initial Image Attachment support through local Session Resources and Provider
projection.
- Provider-hosted Web Search request/evidence plumbing, with opt-in smoke verification.
## What Is Experimental
- Long-running, non-blocking Subagent status and result retrieval in specific clients.
- Workflow partial outcomes and checkpoint bundles as a polished product experience.
- Presenter/client integrations beyond ACP stdio.
- Networked smoke tests for model/provider behavior.
- Skill Context Hydration, which is accepted as a design direction but not yet a public
implemented surface.
## What Is Out Of Scope For This Preview
- Stable public Elixir API.
- Broad package ecosystem or extension API promises.
- MCP server support.
- Packaged T3Code provider.
- Self-update/install channel.
- Production SLA, telemetry, or hosted service guarantees.
## Newcomer Smoke
The expected first-run proof is:
```bash
git clone https://github.com/Ranvier-Technologies/pixir-harness.git
cd pixir-harness
mix deps.get
mix escript.build
./pixir doctor --json
```
Run this smoke against the current checkout or installed package before reporting setup
results. Use `pixir` instead of `./pixir` for package installs.
## Feedback To Capture
When a preview user reports a failure, ask for:
- exact OS and Elixir version;
- command run;
- `pixir doctor --json` output with secrets removed;
- whether they used ChatGPT subscription login or `OPENAI_API_KEY`;
- the relevant `.pixir/sessions/<id>.ndjson` only when safe to share.