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a2a-platform
2026-06-26 19:54:08 +00:00
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{
"schema_version": "2026-06-04",
"language": "python",
"name": "jordan-demo",
"description": "A new A2A agent",
"version": "0.1.0",
"entrypoint": {
"module": "agent",
"class_name": "JordanDemo",
"function": null,
"command": []
},
"skills": [
{
"name": "say_hi",
"description": "Say Hi",
"handler": "say_hi",
"tags": [],
"scopes": [],
"stream": false,
"policy": {
"timeout_seconds": null,
"idempotent": false,
"max_retries": 0,
"cost_class": null,
"allow_scope_expansion": false,
"grant_mode": null,
"grant_allow_patterns": [],
"grant_deny_patterns": [],
"grant_outputs_prefix": null,
"grant_write_prefixes": [],
"grant_ttl_seconds": null,
"grant_run_timeout_seconds": null,
"grant_approval_timeout_seconds": null,
"grant_scope_approval_timeout_seconds": null
},
"input_schema": {
"type": "object",
"properties": {
"name": {
"type": "string"
}
},
"required": [
"name"
],
"additionalProperties": false
},
"output_schema": {
"type": "string"
}
},
{
"name": "ask",
"description": "Ask the starter DeepAgent to answer with tool calls when useful",
"handler": "ask",
"tags": [],
"scopes": [],
"stream": false,
"policy": {
"timeout_seconds": null,
"idempotent": false,
"max_retries": 0,
"cost_class": null,
"allow_scope_expansion": false,
"grant_mode": null,
"grant_allow_patterns": [],
"grant_deny_patterns": [],
"grant_outputs_prefix": null,
"grant_write_prefixes": [],
"grant_ttl_seconds": null,
"grant_run_timeout_seconds": null,
"grant_approval_timeout_seconds": null,
"grant_scope_approval_timeout_seconds": null
},
"input_schema": {
"type": "object",
"properties": {
"prompt": {
"type": "string"
}
},
"required": [
"prompt"
],
"additionalProperties": false
},
"output_schema": {
"type": "string"
}
}
],
"capabilities": {},
"input_modes": [
"application/json"
],
"output_modes": [
"application/json"
],
"required_secrets": [],
"required_env": [],
"consumer_setup": {
"fields": []
},
"runtime": {
"lifecycle": "ephemeral",
"availability": "on_demand",
"state": "none",
"sandbox": "microsandbox",
"resources": {
"cpu": "100m",
"memory": "256Mi",
"gpu": 0,
"max_runtime_seconds": 600
},
"concurrency": 1,
"egress": {
"allow_hosts": [],
"allow_internal_services": [],
"deny_internet_by_default": true
},
"tools_used": [
"deepagents",
"langchain"
],
"llm_provisioning": "platform",
"pricing": {
"price_per_call_usd": 0.0,
"caller_pays_llm": true,
"notes": "Starter agent uses the caller's saved LLM credential via ctx.llm."
},
"wants_cp_jwt": false,
"platform_resources": {
"memory": null,
"databases": []
},
"endpoints": [],
"apt_packages": []
},
"template_lineage": null,
"meta_agent_manifest": null,
"state_schema": null,
"workspace_access": {
"enabled": true,
"max_files": 64,
"allowed_modes": [
"read_only",
"read_write_overlay"
],
"require_reason": false,
"deny_patterns": [],
"require_human_approval": false,
"max_total_size_bytes": 104857600
},
"config_schema": {
"properties": {},
"title": "JordanDemoConfig",
"type": "object"
},
"auth": {
"model": "a2a_pack.auth.NoAuth",
"strategy": "public",
"principal_schema": {
"additionalProperties": false,
"description": "Public agent: no caller identity required.",
"properties": {},
"title": "NoAuth",
"type": "object"
},
"resolver": null,
"required": false
},
"metadata": {
"source": "python-a2a-pack",
"project_manifest": {
"name": "jordan-demo",
"version": "0.1.0",
"entrypoint": "agent:JordanDemo"
}
}
}

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README.md Normal file
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# jordan-demo
A new A2A agent
This project was scaffolded with `a2a init`. It starts as a DeepAgents-backed
A2A agent that uses the caller's saved LLM credential from `ctx.llm`.
`LLMProvisioning.PLATFORM` and `LLMProvisioning.CALLER_PROVIDED` both read that
same `ctx.llm` path. Do not read provider keys, LiteLLM master keys,
`OPENAI_API_KEY`, or `A2A_LITELLM_KEY` directly in agent code, and do not
substitute fake fallback API keys when `ctx.llm.api_key` is empty.
## Durable Files
A2A Cloud workspaces are grant-scoped and backed by MinIO. Files become durable
when your agent uses one of the platform-owned file paths:
- `ctx.workspace` for direct workspace reads and writes
- `ctx.write_artifact(...)` for explicit output artifacts
- `ctx.sandbox` for commands that read or write files in a sandbox
- `ctx.workspace_backend()` for framework file tools such as DeepAgents
DeepAgents has its own built-in file tools (`write_file`, `read_file`,
`edit_file`). Without an A2A backend, those tools write into LangGraph state
only, so files can appear to the agent but never reach MinIO or `/workspace`.
Keep this line when building DeepAgents graphs:
```python
backend = ctx.workspace_backend()
return create_a2a_deep_agent(ctx, backend=backend, tools=[...])
```
Invoke DeepAgents graphs with the starter recursion budget:
```python
state = await graph.ainvoke(
{"messages": [{"role": "user", "content": prompt}]},
config={"recursion_limit": 500},
)
```
The backend respects the caller's grant. In handoffs, generated files should go
through `ctx.workspace_backend()`, `ctx.write_artifact(...)`, or a sandbox helper
so they are mirrored to the caller workspace instead of becoming private virtual
files.
For stable, human-readable paths, write intentional outputs to
`/workspace/outputs/...` or `ctx.write_artifact(...)`. If sandboxed code writes
to process-local paths such as `/tmp/result.csv`, `/root`, or `/app`, the
platform captures changed rootfs files under `outputs/rootfs-captures/...` so
the caller can still download and inspect them.
When a skill needs to run real code, render media, convert files, or call a
CLI that writes outputs, use the workspace-mounted sandbox helpers:
```python
result = await ctx.workspace_shell(
"python script.py --out /tmp/result.txt",
image="python:3.11-slim",
timeout_seconds=120,
)
```
Do not rely on `asyncio.create_subprocess_exec(...)` for durable outputs. A
plain subprocess runs in the agent container, which is not mounted to the
caller workspace; files it creates in `/tmp` or the image filesystem can vanish
after the request. Use the sandbox helpers for any file-producing toolchain.
## DeepAgents Skills
If this project grows reusable workflow knowledge, add source-controlled skill
folders under `skills/<skill-name>/SKILL.md`. The starter's `_seed_runtime_skills`
helper copies those packaged skills into the invocation workspace and passes the
resulting source path to `create_a2a_deep_agent(..., skills=[...])`, which is
how DeepAgents discovers skills with progressive disclosure.
## Run Locally
```bash
python -m pip install -r requirements.txt
a2a dev
a2a test
a2a test --invoke --skill summarize --args-json '{"text":"hello"}'
a2a card
```
`a2a dev` loads `.env.local`, creates `.a2a/workspace/{inputs,outputs}`, serves
the same HTTP invoke/card/MCP endpoints as production, and hot reloads local
code. Files written through `ctx.workspace_backend()` land under
`.a2a/workspace/outputs` before you deploy.
## Auth
The template is public by default (`auth_model = NoAuth`). To require the
caller's app login, declare a typed auth model and resolver in `agent.py`.
Resolvers receive the inbound bearer token and return the principal exposed as
`ctx.auth`.
Hosted browser/direct invokes that use `LLMProvisioning.PLATFORM` still need an
A2A Cloud session so the runtime can mint a short-lived LLM/workspace grant for
that user. Agent-to-agent handoffs pass that grant explicitly.
```python
from a2a_pack import JWTAuth, OIDCUserInfoAuthResolver
auth_model = JWTAuth
auth_resolver = OIDCUserInfoAuthResolver(
"https://auth.example.com/oauth2/userinfo",
auth_model=JWTAuth,
)
```
For homegrown auth or SAML-backed apps, expose a bearer-token `/me` or
`/introspect` endpoint and use the same resolver contract.
## Deploy
```bash
a2a deploy
```

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a2a.yaml Normal file
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# Project identity for `a2a deploy`. Most metadata (resources, scopes,
# secrets, workspace, etc.) lives on the Python class — this file only
# tells the CLI how to find it.
name: jordan-demo
version: 0.1.0
entrypoint: agent:JordanDemo
expose:
public: true
# Optional platform resources:
# resources:
# memory:
# tiers: [kv, vector]
# namespace: jordan-demo
# databases:
# - name: app
# provider: neon
# engine: postgres
# env:
# url: DATABASE_URL

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"""jordan-demo agent.
Starter stack:
- DeepAgents for tool-calling orchestration
- Caller-provided LLM credentials via ctx.llm
- A tiny model-call middleware hook you can replace with tracing,
routing, rate limits, or policy checks
"""
from __future__ import annotations
import json
from pathlib import Path
from typing import Any
from pydantic import BaseModel
from a2a_pack import (
A2AAgent,
LLMProvisioning,
NoAuth,
Pricing,
RunContext,
WorkspaceAccess,
WorkspaceMode,
skill,
)
from a2a_pack.context import LLMCreds
class JordanDemoConfig(BaseModel):
pass
SYSTEM_PROMPT = """\
You are a compact tool-calling agent.
Use the text_stats tool when the user asks about text, counts, summaries,
or anything where exact length/word numbers would help. Mention tool results
briefly instead of dumping raw JSON.
"""
RUNTIME_SKILLS_DIR = "jordan-demo/.deepagents/skills/"
DEEPAGENTS_RECURSION_LIMIT = 500
class JordanDemo(A2AAgent[JordanDemoConfig, NoAuth]):
name = "jordan-demo"
description = "A new A2A agent"
version = "0.1.0"
config_model = JordanDemoConfig
auth_model = NoAuth
# Hosted generated agents read the caller's saved LLM credential through
# ctx.llm. The platform may proxy that credential through LiteLLM, but agent
# code never reads provider keys, LiteLLM master keys, or OPENAI_API_KEY
# directly.
llm_provisioning = LLMProvisioning.PLATFORM
pricing = Pricing(
price_per_call_usd=0.0,
caller_pays_llm=True,
notes="Starter agent uses the caller's saved LLM credential via ctx.llm.",
)
workspace_access = WorkspaceAccess.dynamic(
max_files=64,
allowed_modes=(WorkspaceMode.READ_ONLY, WorkspaceMode.READ_WRITE_OVERLAY),
require_reason=False,
)
tools_used = ("deepagents", "langchain")
@skill(description="Say Hi")
async def say_hi(self, ctx: RunContext[NoAuth], name: str) -> str:
await ctx.emit_progress(f"llm: {ctx.llm.model} via {ctx.llm.source}")
return f"Hi {name}! This is a2a agent {self.name} v{self.version}."
@skill(description="Ask the starter DeepAgent to answer with tool calls when useful")
async def ask(self, ctx: RunContext[NoAuth], prompt: str) -> str:
creds = ctx.llm
await ctx.emit_progress(f"llm: {creds.model} via {creds.source}")
if not creds.api_key:
return (
"LLM key required. Add an LLM credential in Settings > LLM "
"credentials before running this agent; for local --invoke "
"runs set AGENT_LLM_KEY."
)
graph = self._build_deep_agent(ctx=ctx, creds=creds)
state = await graph.ainvoke(
{"messages": [{"role": "user", "content": prompt}]},
config={"recursion_limit": DEEPAGENTS_RECURSION_LIMIT},
)
await ctx.emit_progress("deepagent finished")
return _last_message_text(state)
def _build_deep_agent(
self,
*,
ctx: RunContext[NoAuth],
creds: LLMCreds,
) -> Any:
# Lazy imports keep `a2a card` usable before local dependencies are
# installed. `a2a deploy` installs requirements.txt during the build.
from a2a_pack.deepagents import create_a2a_deep_agent
from langchain.agents.middleware import wrap_model_call
from langchain_core.tools import tool
@tool
def text_stats(text: str) -> str:
"""Return exact word, character, and line counts for text."""
words = [part for part in text.split() if part.strip()]
return json.dumps(
{
"characters": len(text),
"words": len(words),
"lines": len(text.splitlines()) or 1,
}
)
@wrap_model_call
async def log_model_call(request: Any, handler: Any) -> Any:
messages = request.state.get("messages", [])
print(
"[middleware] model_call "
f"model={creds.model} source={creds.source} messages={len(messages)}"
)
return await handler(request)
backend = ctx.workspace_backend()
skill_sources = _seed_runtime_skills(backend, ctx)
# create_a2a_deep_agent resolves provider:model strings with
# langchain.init_chat_model from ctx.llm, preserving LiteLLM routing,
# provider-specific extra body, and runtime model overrides.
return create_a2a_deep_agent(
ctx,
creds=creds,
backend=backend,
skills=skill_sources or None,
tools=[text_stats],
middleware=[log_model_call],
system_prompt=SYSTEM_PROMPT,
)
def _runtime_skills_root(ctx: RunContext[Any]) -> str:
workspace = getattr(ctx, "_workspace", None)
prefixes = tuple(getattr(workspace, "write_prefixes", ()) or ())
if not prefixes:
outputs_prefix = getattr(workspace, "outputs_prefix", None)
prefixes = (outputs_prefix or "outputs/",)
prefix = str(prefixes[0]).strip("/")
return f"/{prefix}/{RUNTIME_SKILLS_DIR}" if prefix else f"/{RUNTIME_SKILLS_DIR}"
def _seed_runtime_skills(backend: Any, ctx: RunContext[Any]) -> list[str]:
"""Copy packaged DeepAgents skills into the invocation workspace.
DeepAgents loads skills from its backend, while source-controlled
``skills/`` folders live in the image. This bridge lets generated agents
ship reusable SKILL.md bundles without giving up durable A2A workspace
files.
"""
root = Path(__file__).parent / "skills"
if not root.exists():
return []
runtime_skills_root = _runtime_skills_root(ctx)
uploads: list[tuple[str, bytes]] = []
for path in root.rglob("*"):
if path.is_file():
rel = path.relative_to(root).as_posix()
uploads.append((runtime_skills_root + rel, path.read_bytes()))
if uploads:
backend.upload_files(uploads)
return [runtime_skills_root]
return []
def _last_message_text(state: dict[str, Any]) -> str:
messages = state.get("messages") or []
if not messages:
return json.dumps(state, default=str)
content = getattr(messages[-1], "content", None)
if isinstance(content, str):
return content
if isinstance(content, list):
parts: list[str] = []
for item in content:
if isinstance(item, dict):
text = item.get("text") or item.get("content")
if text:
parts.append(str(text))
elif item:
parts.append(str(item))
return "\n".join(parts) if parts else json.dumps(content, default=str)
return str(content or messages[-1])

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requirements.txt Normal file
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# a2a-pack is auto-installed by the deploy build.
# These starter deps power the DeepAgents tool-calling example in agent.py.
deepagents>=0.5.0
langchain>=0.3
langchain-openai>=0.2
langgraph>=0.6