PRAXO-CORE Erlang Core

PRAXO-CORE is an embeddable, MIT-licensed agent framework. This package is its native Erlang Core with source tag erlang/v0.3.1. 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, and tool selection. It does not call Go or another Core.

• Implementation type: Core.
• Package version: 0.3.1; supported SPEC_VERSION: 0.2.0.
• Hex package name: praxo_core_erlang; OTP application name: praxo_core.
• The latest Hex package is praxo_core_erlang@0.1.1; 0.3.1 is a source release.
• Toolchain: Erlang/OTP 29 or newer. JSON uses the OTP json module.

Install

{deps, [{praxo_core_erlang, "0.1.1"}]}.

• 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/0.3.1.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.