PRAXO-CORE Erlang Core

PRAXO-CORE is an embeddable, MIT-licensed agent framework. This package is its native Erlang Core with source tag erlang/v0.4.0. It passes all eleven shared vector groups on Erlang/OTP 29 and includes the native agent loop, memory store, checkpoint allowlist, lexical path policy, context compaction, event sinks, middleware helpers, tool selection, and human-in-the-loop interrupt decisions. It does not call Go or another Core.

• Implementation type: Core.
• Package version: 0.4.0; supported SPEC_VERSION: 0.2.0.
• Hex package name: praxo_core_erlang; OTP application name: praxo_core.
• The Hex package is praxo_core_erlang@0.3.1; 0.2.0 is also published as a backfill.
• Toolchain: Erlang/OTP 29 or newer. JSON uses the OTP json module.

Install

{deps, [{praxo_core_erlang, "0.3.1"}]}.

• Local gate: eleven vector groups, native regression tests, API snapshot, and parity inventory.

Build and Test

From the repository root:

python language/erlang/run-tests.py
python language/erlang/api-snapshot.py --check

Set ERLC and ERL to select the compiler and runtime. The Python runner only launches erlc, erl, and the API checks; the implementation and tests are Erlang. Build output stays under language/erlang/build/ebin/.

To build manually from language/erlang/:

erlc -I src -o build/ebin src/*.erl conformance/*.erl tests/*.erl
erl -noshell -pa build/ebin -eval "praxo_conformance:main()." -s init stop
erl -noshell -pa build/ebin -eval "praxo_tests:run()." -s init stop

Usage

Model = praxo_agent:static_model(<<"hello">>),
Options = praxo_agent:new_agent_options(Model),
{ok, Result, _Options} =
    praxo_agent:run_agent(Options, praxo_models:session(<<"demo">>), <<"hello">>),
io:format("~s~n", [maps:get(output, Result)]).

Public declarations are inventoried in api/0.4.0.txt. This is a source declaration check, not a binary ABI promise. Regenerate it with python api-snapshot.py.

Current Limits

• The verified target is Erlang/OTP 29. Older releases without the json module are not supported.
• No provider adapter, HTTP streaming runtime, plugin host, or persistent session store is provided. The loop is synchronous; tool batches can execute in spawned processes when max_parallel_tools is greater than one.
• Optional cancellation, on_stream, and max_parallel_tools agent options add cooperative cancellation, stream parts, and bounded parallel tool execution. praxo_sse:parse/1 rejects truncated and half-packet streams.
• PII redaction, structured output, per-run call limits, and tool selection are opt-in and integrated into the agent loop.
• Path checks are lexical and do not resolve symlinks or reparse points; they are not an OS containment boundary.
• Model and tool callbacks are caller-supplied functions. Callback exceptions are not converted to contract errors.
• Core-local errors and exception terms are not new shared wire error codes. Passing the vectors does not establish full Core parity or production readiness.

The source is MIT; see LICENSE. Erlang/OTP is a separate toolchain, not vendored code.

See CHANGELOG.md for per-release changes and compatibility notes.

See language policy, parity inventory, SETUP.md, and implementation support.