The A2A CLI on Azure: One Client for Container Apps, Agent Framework and Localhost

A developer published a step-by-step guide and open-source repository showing how to run A2A 1.0 agents on Azure and drive them with a single A2A CLI. The setup pairs a Rust agent built on the official A2A Rust SDK with a Microsoft Agent Framework coordinator on Azure OpenAI's gpt-5.4-mini, both deployed to Azure Container Apps behind Entra ID and also runnable locally, with the CLI executing the same commands against all four endpoints and passing 19 of 19 checks. All access uses Entra ID tokens via az login, with no API keys anywhere in the stack.

This article provides a step by step guide to running A2A agents on Azure and driving them with the A2A CLI. A Rust agent on the official A2A Rust SDK runs in Azure Container Apps. A Microsoft Agent Framework agent on an Azure OpenAI model runs in Container Apps behind Entra ID and hands its work to the Rust agent. Both also run on a laptop, and one set of a2a commands checks all four. https://github.com/xbill9/rust-dev/tree/main/a2a-agentframework-azure https://github.com/xbill9/rust-dev/tree/main/a2a-agentframework-azure The A2A CLI drove all four endpoints with the same commands, and 19 of 19 checks passed. Every hop speaks A2A 1.0: the Rust SDK serves it, Agent Framework serves it, and the Agent Framework agent calls the Rust agent with the A2A 1.0 Python client. On Azure the CLI needs one extra flag, an Entra ID bearer token, which az login already provides. Model access, registry pulls and the token all run on Entra ID, with no API key anywhere. | Agent | Where it runs | A2A | Model | |---|---|---|---| | mersenne-agent Rust | laptop, port 8304 | 1.0, JSON-RPC and REST | none | | mersenne-agent same image | Container Apps, 0.25 vCPU, 0.5 GiB | 1.0, JSON-RPC and REST | none | | Agent Framework coordinator | laptop, port 8309 | 1.0, JSON-RPC and REST | gpt-5.4-mini on Azure OpenAI | | Agent Framework coordinator same code | Container Apps, Entra ID auth | 1.0, JSON-RPC and REST | gpt-5.4-mini on Azure OpenAI | a2a CLI ──► Container Apps auth Entra ID token ──► Agent Framework Agent ──Entra ID──► Azure OpenAI gpt-5.4-mini └── find mersenne primes tool └── a2a-sdk 1.x client ──► Container Apps A2A 1.0 ──► mersenne-agent a2a CLI ────────────────────────────────────────────────────────────────────────────────► Container Apps A2A 1.0 The workload is a Lucas-Lehmer test over the first N known Mersenne prime exponents, timed by the agent itself. Every reply carries the line Found first N Mersenne primes in X ms. and a data part with requested , found and elapsed ms . Versions, read from the machine on 2026-11-06: | Component | Version | |---|---| | A2A CLI a2a | v0.3.1 | | a2a-lf / a2a-server-lf Rust SDK, A2A 1.0 | 0.4.2 / 0.5.3 | | agent-framework-core / agent-framework-openai / agent-framework-a2a | 1.24.0 / 1.18.0 / 1.0.0b261030 | | a2a-sdk Python, A2A 1.0 / azure-identity | 1.3.0 / 1.27.0 | | Python / Rust | 3.14.7 / 1.99.1 | | Azure CLI | 2.90.0 | | Model | gpt-5.4-mini 2026-03-17, GlobalStandard | | Region | eastus2 | PATH as a2a : go install github.com/a2aproject/a2a-cli@latest , then rename a2a-cli to containerapp extension, signed in with az login to a subscription where you can create resource groups and Entra ID app registrations a2a version a2a v0.3.1 git clone https://github.com/xbill9/rust-dev && cd rust-dev/a2a-agentframework-azure scripts/deploy-model.py The script creates one resource group in eastus2 holding a container registry, a user-assigned managed identity, a Container Apps environment and an AIServices account with a gpt-5.4-mini deployment. It grants "Cognitive Services OpenAI User" on the account twice: to the signed-in user, for the laptop, and to the managed identity, for the containers. bash $ az group create -n a2a-agentframework-azure-rg -l eastus2 $ az containerapp env create -n a2a-af-env -g a2a-agentframework-azure-rg -l eastus2 --logs-destination none $ az cognitiveservices account create -n a2a-af-openai-defaba -g a2a-agentframework-azure-rg -l eastus2 --kind AIServices --sku S0 --custom-domain a2a-af-openai-defaba --yes $ az cognitiveservices account deployment create ... --model-name gpt-5.4-mini --model-version 2026-03-17 --model-format OpenAI --sku-name GlobalStandard --sku-capacity 50 ✅ https://a2a-af-openai-defaba.cognitiveservices.azure.com/ deployment gpt-5.4-mini The account gets a custom subdomain, and every call to the model authenticates with Entra ID. The coordinator holds no key. scripts/start-local.sh php up: 8304 rust agent, 8309 agent framework coordinator - http://localhost:8304 The coordinator is an Agent Framework Agent with one tool, served over A2A 1.0 by agent framework a2a on the a2a-sdk server routes. The same file runs on the laptop and in Container Apps: client = OpenAIChatClient model=MODEL, azure endpoint=os.environ "AZURE OPENAI ENDPOINT" , credential=DefaultAzureCredential , agent = Agent client=client, name=NAME, description=DESCRIPTION, instructions=INSTRUCTIONS, tools= find mersenne primes handler = DefaultRequestHandler agent executor=WholeTextA2AExecutor agent, stream=True , task store=InMemoryTaskStore , agent card=card, return Starlette routes= create agent card routes card , create rest routes handler, path prefix="/rest" , create jsonrpc routes handler, "/" , DefaultAzureCredential picks up az login on the laptop and the managed identity in Azure. The CLI reads both cards and shows each one's protocol version: a2a card get -a http://localhost:8304 a2a card get -a http://localhost:8309 Name: Mersenne Prime Agent Rust Version: 0.1.0 Interfaces: JSONRPC A2A v1.0 http://localhost:8304/jsonrpc HTTP+JSON A2A v1.0 http://localhost:8304/rest Name: Agent Framework Mersenne Coordinator Version: 0.1.0 Interfaces: JSONRPC A2A v1.0 http://localhost:8309/ HTTP+JSON A2A v1.0 http://localhost:8309/rest Agent Framework's A2A package is built on a2a-sdk 1.x, the same protocol version as the Rust agent. The tool sends a data part and reads the Rust agent's structured report straight from the reply: value = Value value.struct value.update {"count": count} request = SendMessageRequest message=Message role=Role.ROLE USER, message id=os.urandom 16 .hex , parts= Part data=value , async with httpx.AsyncClient timeout=60 as http: client = await create client RUST AGENT URL, ClientConfig streaming=False, httpx client=http async for event in client.send message request : task = event.task if event.HasField "task" else None for artifact in task.artifacts if task else : for part in artifact.parts: if part.HasField "data" : report = MessageToDict part.data elif part.HasField "text" : summary = part.text The tool refuses a reply whose requested or found differs from the count the model asked for, and the instructions tell the model to quote the agent's own reply line. The model picks N; the Rust agent does the counting and the timing. Data parts cross a protobuf Struct , so integers arrive as floats and the tool reads them with int . agent-framework-a2a requires a2a-sdk 1.x, and the same machine runs a Strands rig whose a2a-sdk is pinned to 0.3: agent-framework-a2a wheel metadata Requires-Dist Requires-Dist: agent-framework-core =1.22.0,<2 Requires-Dist: a2a-sdk =1.0.0,<2 shared pyenv Python used by the Strands rig a2a-sdk 0.3.26 scripts/start-local.sh installs the coordinator's pinned requirements into build/local-site with pip install --target , and starts the coordinator with PYTHONPATH=build/local-site . The two SDK versions never meet, and the container image installs the same pins. scripts/deploy-rust.py builds docker/agent.Dockerfile , pushes it to the registry and creates a container app with external ingress. The app pulls with the managed identity, which holds AcrPull, so there is no registry password. The script computes the app's address from the environment's default domain before creating it and sets ADVERTISE URL to it, so the card points at Container Apps from the first revision. scripts/deploy-rust.py bash $ docker build --platform linux/amd64 -f docker/agent.Dockerfile -t a2aafazuredefaba.azurecr.io/mersenne-agent:20261106T153734Z /home/xbill/rust-dev/a2a-agentframework-azure $ docker push a2aafazuredefaba.azurecr.io/mersenne-agent:20261106T153734Z $ az containerapp create -n a2a-rust-mersenne ... --target-port 8080 --ingress external --registry-identity <identity --cpu 0.25 --memory 0.5Gi --min-replicas 1 --max-replicas 1 --env-vars PORT=8080 HOST=0.0.0.0 ADVERTISE URL=https://a2a-rust-mersenne.braveground-531dbad2.eastus2.azurecontainerapps.io ✅ https://a2a-rust-mersenne.braveground-531dbad2.eastus2.azurecontainerapps.io/.well-known/agent-card.json The commands are the laptop's, with the Container Apps address: scripts/test-cli.sh aca-rust == aca-rust rust agent https://a2a-rust-mersenne.braveground-531dbad2.eastus2.azurecontainerapps.io Interfaces: JSONRPC A2A v1.0 https://a2a-rust-mersenne.braveground-531dbad2.eastus2.azurecontainerapps.io/jsonrpc HTTP+JSON A2A v1.0 https://a2a-rust-mersenne.braveground-531dbad2.eastus2.azurecontainerapps.io/rest ✅ aca-rust card A2A v1.0 ✅ aca-rust send ✅ aca-rust stream ✅ aca-rust rest ✅ aca-rust data-part scripts/deploy-coordinator.py does four things: api://<app id , one delegated scope access as user , version 2 access tokens, and the Azure CLI's client id pre-authorized on that scope docker/coordinator.Dockerfile and pushes it RUST AGENT URL set to the Container Apps Rust agent and AZURE CLIENT ID set to the managed identity scripts/deploy-coordinator.py bash $ az containerapp auth microsoft update -n a2a-af-coordinator -g a2a-agentframework-azure-rg --client-id 67ce79d7-7432-4261-b394-d32c2fc36890 --issuer https://login.microsoftonline.com/<tenant /v2.0 --allowed-audiences api://67ce79d7-7432-4261-b394-d32c2fc36890,67ce79d7-7432-4261-b394-d32c2fc36890 --yes $ az containerapp auth update -n a2a-af-coordinator -g a2a-agentframework-azure-rg --enabled true --unauthenticated-client-action Return401 ✅ https://a2a-af-coordinator.braveground-531dbad2.eastus2.azurecontainerapps.io/.well-known/agent-card.json 401 without a token From the CLI, the coordinator takes one flag beyond the laptop's: a bearer token for the app registration. URL=$ scripts/azure state.py get coordinator url TOKEN=$ scripts/entra-token.py az account get-access-token --resource api://<app id a2a --auth "Bearer $TOKEN" card get -a "$URL" a2a --auth "Bearer $TOKEN" send -a "$URL" --transport rest "Find the first 3 Mersenne primes" Name: Agent Framework Mersenne Coordinator Interfaces: JSONRPC A2A v1.0 https://a2a-af-coordinator.braveground-531dbad2.eastus2.azurecontainerapps.io/ HTTP+JSON A2A v1.0 https://a2a-af-coordinator.braveground-531dbad2.eastus2.azurecontainerapps.io/rest Status: completed 2026-11-06T16:20:22Z Artifacts: msg 0a2ef6a5893a0e6d006aedfe460ca48195931f337d1ca8db4e Found first 3 Mersenne primes in 0.0030ms. 2, 3, 5 The CLI takes the base URL, the card sits at the standard /.well-known/agent-card.json path, and each call gets its own A2A context with no session header. Without a token, and with a malformed one, the card itself answers 401: bash $ curl -s -o /dev/null -w '%{http code}' $URL/.well-known/agent-card.json 401 $ curl -s -o /dev/null -w '%{http code}' -H 'Authorization: Bearer not-a-jwt' $URL/.well-known/agent-card.json 401 With the Azure CLI's client id listed under preAuthorizedApplications for the access as user scope, az account get-access-token --resource api://<app id returns a token for the coordinator with no consent prompt and no client secret. The token's claims, payload only: { "aud": "67ce79d7-7432-4261-b394-d32c2fc36890", "iss": "https://login.microsoftonline.com/40482c55-d00d-4c6d-8903-643d76a74b9c/v2.0", "ver": "2.0", "scp": "access as user", "azp": "04b07795-8ddb-461a-bbee-02f9e1bf7b46" } azp is the Azure CLI. With requestedAccessTokenVersion: 2 the audience is the bare app id and the issuer ends in /v2.0 , so the built-in authentication lists both api://<app id and <app id as allowed audiences and uses the v2 issuer. azure.identity.aio needs aiohttp for managed identity, and nothing in the Agent Framework or a2a-sdk dependency tree installs it. The same requirements without the pin, in a clean python:3.14-slim-trixie container: aiohttp dist-info dirs installed: 0 ImportError: aiohttp package is not installed coordinator/requirements.txt pins aiohttp==3.14.5 . A shared Python on a laptop that already has aiohttp from another package hides the gap, so the clean container is the place to check it. Agent Framework's OpenAI client streams a reply as text deltas, then sends one more update holding the whole text under the same message id. One streamed reply, every text update: 1 msg 02d7537ef107 'Found' 2 msg 02d7537ef107 ' first' ... 21 msg 02d7537ef107 ' 7' 22 msg 02d7537ef107 'Found first 4 Mersenne primes in 0.0026ms.\n2, 3, 5, 7' last update repeats everything streamed before it under the same message id: True A2AExecutor appends every update to one artifact, which leaves the reply in the task twice. WholeTextA2AExecutor lets the closing update replace the artifact, so streaming clients see the deltas and the finished task holds the reply once, as a single text part: python class WholeTextA2AExecutor A2AExecutor : async def handle events self, item, updater, streamed artifact ids=None, default artifact id=None : if isinstance item, AgentResponseUpdate : key = item.message id or default artifact id or "" text = "".join c.text for c in item.contents if c.type == "text" and c.text so far = self. streamed.get key, "" if text and so far and text == so far: del self. streamed key if streamed artifact ids is not None: streamed artifact ids.discard key next add artifact replaces elif text: self. streamed key = so far + text await super .handle events item, updater, streamed artifact ids, default artifact id a2a --auth "Bearer $TOKEN" send -a "$URL" -o json "Find the first 10 Mersenne primes" "artifacts": { "artifactId": "msg 0df9fa92840724f8006aedfe47b9208195b7c9c1698118b7c1", "parts": { "text": "Found first 10 Mersenne primes in 0.0549ms.\n2, 3, 5, 7, 13, 17, 19, 31, 61, 89" } } The coordinator checks in the next step require the reply line exactly once, and the timing script counts a call only when it appears once. scripts/test-cli.sh all starts the laptop agents and runs one set of checks against each endpoint. Each Rust agent gets card A2A v1.0 , send, stream, REST and a data part. Each coordinator gets card A2A v1.0 , send, stream and REST, and the Container Apps coordinator also gets a request with no token, which must answer 401. scripts/test-cli.sh all == local rust agent http://localhost:8304 ✅ local card A2A v1.0 ✅ local send ✅ local stream ✅ local rest ✅ local data-part == local agent framework coordinator http://localhost:8309 ✅ local card A2A v1.0 ✅ local send ✅ local stream ✅ local rest == aca-rust rust agent https://a2a-rust-mersenne.braveground-531dbad2.eastus2.azurecontainerapps.io ✅ aca-rust card A2A v1.0 ✅ aca-rust send ✅ aca-rust stream ✅ aca-rust rest ✅ aca-rust data-part -- without a token expect 401 ✅ aca-coordinator rejects no token 401 == aca-coordinator agent framework coordinator https://a2a-af-coordinator.braveground-531dbad2.eastus2.azurecontainerapps.io ✅ aca-coordinator card A2A v1.0 ✅ aca-coordinator send ✅ aca-coordinator stream ✅ aca-coordinator rest The Container Apps coordinator checks ask for 7, 11 and 3 primes. All three reached the Container Apps Rust agent, and the coordinator's log shows each one: INFO:coordinator:rust agent https://a2a-rust-mersenne.braveground-531dbad2.eastus2.azurecontainerapps.io: Found first 7 Mersenne primes in 0.0059ms. INFO:coordinator:rust agent https://a2a-rust-mersenne.braveground-531dbad2.eastus2.azurecontainerapps.io: Found first 11 Mersenne primes in 0.0339ms. INFO:coordinator:rust agent https://a2a-rust-mersenne.braveground-531dbad2.eastus2.azurecontainerapps.io: Found first 3 Mersenne primes in 0.0039ms. scripts/cli-bench.py starts one a2a process per call and times it, so wall time includes starting the CLI, fetching the card, TLS on Azure and the reply. Targets take turns, one call each per round, so drift during the run lands on every target alike. Every reply is checked, and the statistics come from the script results/summary-20261106.txt . N=10 and 20 calls per target throughout. scripts/cli-bench.py --targets local-rust,aca-rust --reps 20 --n 10 local-rust ok 20/20 wall median 10.5 ms min 7.9, max 12.3 compute median 0.02268 ms aca-rust ok 20/20 wall median 164.2 ms min 143.4, max 199.9 compute median 0.02985 ms scripts/cli-bench.py --targets local-coordinator,aca-coordinator --reps 20 --n 10 local-coordinator ok 20/20 wall median 1836.0 ms min 1374.5, max 4833.5 aca-coordinator ok 20/20 wall median 1891.2 ms min 1581.2, max 4372.4 The Rust agent's own compute time is a fraction of a millisecond on both machines, so the 153.7 ms between the laptop and Container Apps medians is the network and TLS. A coordinator call is an Azure OpenAI call plus a nested A2A call to a Rust agent. The Container Apps coordinator's median sits 55.2 ms above the laptop's, and both ranges span more than a second: the model call sets the time, and where the coordinator runs moves it by less than the spread between calls. make teardown bash $ az ad app delete --id 67ce79d7-7432-4261-b394-d32c2fc36890 $ az group delete -n a2a-agentframework-azure-rg --yes $ az cognitiveservices account purge -n a2a-af-openai-defaba -g a2a-agentframework-azure-rg -l eastus2 deleted a2a-agentframework-azure-rg Everything except the app registration lives in one resource group, so one delete removes it. The app registration lives in Entra ID and is deleted first. The script then purges the AIServices account, so no soft-deleted copy is left behind. Afterwards: bash $ az group exists -n a2a-agentframework-azure-rg false $ az cognitiveservices account list-deleted --query " .name" The Container Apps and model addresses shown in this article belong to that deployment and no longer resolve. make deploy recreates all three steps under new addresses, and make test-cli T=all checks them again. | Endpoint | CLI flags beyond the laptop's | A2A | Median wall time, N=10 | |---|---|---|---| | Rust, laptop 🥇 | none | 1.0 | 10.5 ms | | Rust, Container Apps 🥈 | none, HTTPS address | 1.0 | 164.2 ms | | Agent Framework, laptop | none | 1.0 | 1836.0 ms | | Agent Framework, Container Apps | --auth with an Entra ID token | 1.0 | 1891.2 ms | For an agent with no model in it, Container Apps is the short path: one container app with external ingress, a public HTTPS address and no client changes. Every call costs the network trip, 153.7 ms here, on top of a computation that takes a fraction of a millisecond. For an agent built around a model, the same Container Apps environment hosts it behind Entra ID with built-in authentication and no code in the agent. The CLI adds one flag, and az login supplies the token. The model call sets the response time, wherever the agent runs. For talking to any of them, the A2A CLI is the one client. With Agent Framework on A2A 1.0, the agents talk to each other with the Python SDK and the laptop talks to all of them with the CLI, over one protocol version end to end. The goal of this article was to show that the A2A CLI drives the same agents on a laptop and on Azure Container Apps with the same commands. The key to the solution was A2A 1.0 on every hop, Entra ID for every credential, and one set of checks run against every endpoint. The results were: a2a-sdk 1.x client WholeTextA2AExecutor , or each reply lands in the task twice aiohttp pinned; nothing else installs it Scope: one laptop 13th Gen Intel Core i7-1360P, Linux , one Azure region eastus2 , one replica of each app at 0.25 vCPU and 0.5 GiB, one model gpt-5.4-mini , measured on 2026-11-06. Timing used N=10 with 20 calls per target, one run per comparison. Every Azure figure includes the trip from the laptop. Both apps kept one replica running, so cold starts were not measured; cost, gRPC, task commands, push notifications and load were not tested. The strategy for running A2A agents on Azure and driving them with the A2A CLI was validated with an incremental step by step approach.