feat: add agent skills and use_agent to /strands command

[agent-of-mkmeral]

Summary

Adds a beta agent with its own runner to the /strands command. The beta agent has extended capabilities (skills, sub-agents) while the standard agent remains completely unchanged.

Design: Same pipeline, different agent

/strands <command>        → standard agent (agent_runner.py — UNCHANGED)
/strands beta <command>   → beta agent (beta_agent_runner.py — NEW)

Both go through the same pipeline: parse → run → finalize. The only difference is which runner executes.

Changes to Existing Files

File	Change
agent_runner.py	ZERO changes — identical to main
process-input.cjs	Detect /strands beta ..., set agent_type flag, route modes
action.yml	Read agent_type, conditionally run the right runner + skills setup

New Files

File	Purpose
beta_agent_runner.py	Beta agent runner — imports shared infra from agent_runner.py, adds AgentSkills plugin + use_agent tool
agent-skills/task-adversarial-tester/SKILL.md	Adversarial testing skill
agent-skills/task-release-digest/SKILL.md	Release digest skill with sub-agent orchestration

New Commands

Command	Description
/strands beta	Run the beta agent (default mode based on context)
/strands beta adversarial-test	Break PRs with edge case tests, security holes, and failure modes
/strands beta release-digest	Generate release digests across packages using sub-agents
/strands beta implement	Implement with beta agent (skills + use_agent available)
/strands beta review	Review with beta agent

Existing commands (/strands, /strands implement, /strands review, /strands refine, /strands release-notes) are completely unchanged.

How the beta agent differs from standard

Aspect	Standard	Beta
Runner	agent_runner.py	beta_agent_runner.py
Tools	Standard tools	Standard tools + use_agent
Plugins	None	AgentSkills (SKILL.md format)
Skills dir	Not copied	Copied to working dir
Pipeline	parse → run → finalize	parse → run → finalize (same)
Impact on each other	None	None

Architecture

beta_agent_runner.py imports shared infrastructure from agent_runner.py:

• _get_all_tools() — base tools (beta adds on top)
• _setup_langfuse_telemetry() — telemetry setup
• _get_trace_attributes() — trace attributes
• _send_eval_trigger() — eval triggers
• Model constants (STRANDS_MODEL_ID, etc.)

This means the beta agent automatically inherits any improvements to the shared infra without duplication.

---

Closes the intent from #43. cc @mkmeral

[mkmeral]

I don't want to set up separate workflows. it should be under the same strands command so it works in all repos where we have strands command already

[mkmeral]

@agent-of-mkmeral ☝️

[agent-of-mkmeral]

Reworked per your feedback — everything is now integrated into the existing /strands command. No separate workflows or actions.

What changed

Before (6 new files, 0 modifications):

• Separate /strands-beta command, parser, runner, and actions
• Repos would need to set up new workflows

After (3 modifications, 2 new files):

• process-input.cjs — added adversarial-test and release-digest mode routing
• agent_runner.py — added use_agent tool + AgentSkills plugin (graceful degradation)
• action.yml — checkout and copy agent-skills/ to working directory
• agent-skills/task-adversarial-tester/SKILL.md (new)
• agent-skills/task-release-digest/SKILL.md (new)

How it works

Any repo with /strands already set up gets these automatically:

• /strands adversarial-test — adversarial testing via AgentSkills plugin
• /strands release-digest — release digest with use_agent sub-agents
• All existing commands unchanged

If the AgentSkills plugin or agent-skills/ directory aren't available, the agent works exactly as before — zero risk to existing behavior.

[mkmeral]

no, so i want like a separate agent with it's own runner, sowe can add more tools, plugins to it. but our changes should have no impact to the normal agent.

that said, i want it to use the same pipeline overall, so don't recreate everything. like make agent creation configurable or something. so /strands beta ... is going to through the same pipeline, just to a different agent @agent-of-mkmeral

[agent-of-mkmeral]

Reworked per your feedback @mkmeral — the beta agent now has its own runner, but uses the same pipeline.

What changed in this commit

agent_runner.py — ZERO changes (reverted to main, identical). Normal agent is completely untouched.

beta_agent_runner.py — NEW — Separate runner that:

• Imports shared infra from agent_runner.py (telemetry, trace attributes, tools, model config, eval triggers)
• Adds AgentSkills plugin + use_agent tool on top
• Easy to extend independently — add whatever tools/plugins you want here without touching the normal agent

process-input.cjs — Detects /strands beta ..., strips the prefix, sets agent_type: "beta" in the parsed output. Everything else routes normally.

action.yml — Reads agent_type and conditionally:

• Copies agent-skills/ to working dir (beta only)
• Runs beta_agent_runner.py instead of agent_runner.py (beta only)

The flow

/strands review         → process-input → agent_runner.py      (standard)
/strands beta review    → process-input → beta_agent_runner.py (beta)

Same pipeline (parse → run → finalize). Different agent.

Diff vs main

 action.yml              |  30 ++-   (conditional runner + skills copy)
 task-adversarial-tester  | 108 +++   (new skill)
 task-release-digest      | 107 +++   (new skill)
 process-input.cjs        |  67 ++-   (beta routing)
 beta_agent_runner.py     | 209 +++++ (new runner)
 agent_runner.py          |   0       (UNCHANGED)

5 files changed, 511 insertions, 10 deletions. Zero modifications to agent_runner.py.