# BarunAction-35M candidate-v2 model card

BarunAction-35M is a 35,072,768-parameter local compiler for typed personal-action proposals. It
takes a request, explicit tool schemas, JSON context, and a reference time, then generates one
Action IR v1 JSON object. The reference package hash-verifies the checkpoint, validates inputs and
outputs deterministically, and never invokes a real tool.

Candidate-v2 is useful as a compact structured-generation research model. It is not an autonomous
assistant, safety classifier, permission system, or production-ready executor.

## Model details

| Field | Value |
| --- | --- |
| Model | BarunAction-35M `candidate-v2` |
| Base | `harrrshall/BarunLM-35M` revision `ef3e483a9fd7d906ecf2a7929babeffaf82d1d16` |
| Parameters | 35,072,768 |
| Layers / hidden size | 12 / 448 |
| Attention heads / KV heads | 7 / 1 |
| Attention pattern | three local layers, then one global layer |
| Local window | 256 tokens |
| Feed-forward width | 1,228 |
| Vocabulary | 16,384 byte-level BPE tokens |
| Maximum context | 2,048 tokens |
| Output | Action IR v1 |
| License | Apache-2.0 code and released weights |

The architecture also uses partial RoPE, QK normalization, gated attention outputs, tied
input/output embeddings, and a learned residual selector every four layers. The complete model
configuration is [`barun_config.json`](../barun_config.json).

## Intended use

Appropriate uses include:

- research on compact typed-action generation;
- local proposal compilation for explicitly supplied schemas;
- deterministic parser, schema, and failure-mode experiments; and
- sandboxed demonstrations where external application code owns every permission and side effect.

Do not use the model to directly send messages, edit calendars, modify devices, or call production
services. A real integration needs independent authentication, authorization, confirmation,
identity, rate limiting, audit logging, and tool-specific validation. Valid JSON is not permission
to act.

The package's simulator is in-memory only. It has no calendar, mail, map, contacts, settings,
device-control, or network integration.

## Training summary

Candidate-v2 is a fresh one-epoch, full-parameter, response-only SFT run from the pinned base. It
saw 7,937 Mobile Actions-derived examples exactly once and completed 126 optimizer steps with seed
17, batch size 63, AdamW, peak learning rate `1e-4`, 12 warmup steps, cosine decay, and BF16 CUDA
autocast. Prompt and padding labels were masked; target tokens and one EOS token were supervised.
No row was truncated or dropped.

The run used no synthetic teacher data, distillation, preference pairs, adapters, DPO, or RL. The
exact method, data hashes, optimizer settings, and reproduction path are in
[`docs/training.md`](training.md) and
[`training/candidate-v2-recipe.json`](../training/candidate-v2-recipe.json).

## Evaluation

The released float checkpoint was selected and scored on a grouped 756-row Mobile Actions
development population derived only from public source-training rows. All rows are `CALL` examples
over one seven-tool schema family.

| Model | Exact parameters | Parse valid | Schema valid | Strict AST exact |
| --- | ---: | ---: | ---: | ---: |
| **BarunAction-35M candidate-v2** | **35,072,768** | 756/756 | 755/756 | **602/756 (79.63%)** |
| Qwen2.5-0.5B-Instruct matched baseline | 494,032,768 | 755/756 | 754/756 | 663/756 (87.70%) |

Qwen is 14.09 times larger. BarunAction retains 90.80% of its exact-match rate, but Qwen leads by
61 rows, or 8.07 percentage points. Paired outcomes were 19 BarunAction-only wins, 80 Qwen-only
wins, 583 both correct, and 74 both wrong.

The Qwen model is `Qwen/Qwen2.5-0.5B-Instruct` revision
`7ae557604adf67be50417f59c2c2f167def9a775`: exactly 494,032,768 unique BF16 parameters across
290 tensors, approximately 0.494B—not 500B and not 500 billion. The comparison matched semantic
examples, one training pass, effective batch 63, 126 updates, seed 17, final-checkpoint scoring,
and greedy decoding. It did not match pretraining, prior instruction tuning, tokenizer control
tokens, learning rates, architecture, or prior development-selection budget.

The hypothesis that candidate-v2 would beat this larger matched baseline failed. The useful result
is compactness with substantial retained task accuracy, not an accuracy victory.

Full definitions, per-scenario results, raw continuations, and comparison limitations are in
[`docs/benchmark.md`](benchmark.md), [`docs/evaluation.md`](evaluation.md), and
[`benchmarks/evidence/`](../benchmarks/evidence/).

## Evaluation boundary

The reported score is reused development evidence because the population selected candidate-v2.
The 961 official Mobile Actions evaluation rows were never read, parsed, materialized, trained on,
or scored. No official, hidden, or independent test result is claimed.

Because every development target is `CALL`, the benchmark has zero denominator for false-action,
abstention, clarification, confirmation, unsafe-request, ambiguity, and out-of-scope behavior. A
zero-valued aggregate field with a zero denominator is not a safety measurement.

The result does not establish competence on renamed or unseen schemas, contextual revisions,
disfluencies, prompt injection, broad function calling, or real-world action execution. Calendar
datetime and map argument fidelity are the weakest observed development slices.

## Input contract

The runtime contract versions are:

- prompt: `barunaction-local-prompt-v1`;
- tool declaration: `barunaction-tool-schema-v1`; and
- result: `barunaction-inference-result-v1`.

Every request must provide:

1. non-empty request text;
2. one or more strict, uniquely named tool declarations;
3. a JSON object for context, including `{}` when empty; and
4. a timezone-aware ISO-8601 `now` value.

Tool declarations specify name, description, typed arguments, required names, whether extra
arguments are allowed, and whether the tool is side-effecting. The validator supports strict JSON
scalars, enums, arrays, and nested objects. Duplicate or unknown schema fields, undeclared required
arguments, non-finite numbers, naive timestamps, and reserved role-token text fail closed.

Empty context is omitted from the rendered prompt. Non-empty context is canonicalized to strict
JSON. The runtime accepts exactly one generated JSON object and performs no Markdown stripping,
substring extraction, coercion, defaulting, or repair.

## Output contract

The four syntactically supported decisions are `CALL`, `CONFIRM`, `CLARIFY`, and `ABSTAIN`; call
modes are `SINGLE`, `SERIAL`, and `PARALLEL`. For example:

```json
{
  "calls": [
    {
      "args": {"query": "Cubbon Park, Bengaluru"},
      "tool": "show_map"
    }
  ],
  "decision": "CALL",
  "mode": "SINGLE"
}
```

The released model was supervised only on `CALL`, so the other decisions are runtime schema
capabilities rather than demonstrated model behavior. Every successfully parsed result still sets
`policy.execution_permitted` to `false`.

## Quick start

```console
python -m venv .venv
source .venv/bin/activate
pip install -e .

barunaction download --output ./models/BarunAction-35M
barunaction verify --checkpoint ./models/BarunAction-35M

barunaction infer \
  --checkpoint ./models/BarunAction-35M \
  --tools examples/barunaction_tools.example.json \
  --context examples/barunaction_empty_context.example.json \
  --now 2026-08-03T20:00:00+05:30 \
  --request "Turn on the flashlight" \
  --device cpu
```

A successful proposal exits with status 0 but does not authorize execution. Input, checkpoint,
generation, parse, or schema failure returns structured JSON and exits with status 2.

Python:

```python
import json

from barunaction import BarunActionCompiler, download_candidate_checkpoint

downloaded = download_candidate_checkpoint("./models/BarunAction-35M")
compiler = BarunActionCompiler(downloaded.path, device="cpu")

with open("examples/barunaction_tools.example.json", encoding="utf-8") as source:
    tools = json.load(source)

result = compiler.infer(
    request="Turn on the flashlight",
    tool_schemas=tools,
    context={},
    now="2026-08-03T20:00:00+05:30",
)
print(result.to_dict())
```

The download and loader both verify the candidate's required hashes.

## Sandboxed demonstration

The weight-free demo exercises strict validation and the in-memory policy boundary:

```console
barunaction demo
```

It loads no model, requires no network, and performs no external side effect. Model quality is not
measured by this demo.

## Checkpoint identity

| File | Bytes | SHA-256 |
| --- | ---: | --- |
| `barun_config.json` | 448 | `9b3a1d71baa95a198744d250f9629231738d942570b8685c44307fd83dd33565` |
| `model.safetensors` | 140,304,464 | `fdb95ccf58a095e0d321be998924318b35ee59a334f6dd97d8726d2cf80021d3` |
| `tokenizer.json` | 1,136,031 | `70ded9605fccd09c2340ca7e225361eab0ae8b4dbbb0d6e26343ab5183979db6` |
| `checkpoint_manifest.json` | 549 | `c743ab7c4d33ae75c6b0aa4547458a961b92766da8fcf85fd148fda2ebb5530a` |

The float package also carries `LICENSE`, `NOTICE`, and `MODEL_CARD.md`. Exact immutable artifact
identities and verification commands are in
[`docs/barunaction-retrieval.md`](barunaction-retrieval.md).

## Int8 derivative

A CPU dynamic-int8 derivative is retained only for Darwin ARM64, PyTorch 2.13.0, and QNNPACK. It
quantizes 87 internal Linear modules; embeddings, norms, attention operations, KV state, and the
tied output head remain floating point. It scored 607/756 on the same development IDs and passed a
frozen retention check, but the small timing smoke was slower than float. No general speed,
portability, or int8-accuracy-improvement claim is made. See
[`docs/int8-quantization.md`](int8-quantization.md).

## Data and license

Candidate-v2 was post-trained on `google/mobile-actions` revision
`e920309bc2acbc2e99a5e3201cf37df2b9fd9151`, licensed CC BY 4.0. Training data is not bundled with
the weights and retains its upstream terms. Code and released model weights are Apache-2.0. See
[`NOTICE`](../NOTICE) and the [data card](barunaction-data-card.md).

## Citation

Use [`CITATION.cff`](../CITATION.cff) or:

```bibtex
@software{harrrshall2026barunaction35m,
  author  = {Harrrshall},
  title   = {BarunAction-35M: A Compact Typed Personal-Action Compiler},
  year    = {2026},
  version = {candidate-v2},
  url     = {https://github.com/harrrshall/barunaction-35m},
  license = {Apache-2.0}
}
```