# A2a Send

> Sends a message to an A2A-compliant agent at a URL or alias. Always runs in blocking mode. Pass --background to return immediately with a task ID instead. Resolves aliases, auth params, and timeout from settings. Tracks tasks in session.

- Skill: `christophe1997/a2a-send` (Agent Skill)
- Install (CLI): `npx skillmds@latest add christophe1997/a2a-send`
- Raw SKILL.md: https://api.skillmd.com/api/skills/christophe1997/a2a-send/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: Christophe1997 (https://skillmd.com/u/christophe1997)
- Updated: 2026-09-10
- Page: https://skillmd.com/skills/christophe1997/a2a-send

---


Parse `$ARGUMENTS` into:
- `URL_OR_ALIAS`: first non-flag token
- `MESSAGE`: all remaining non-flag tokens joined as the message string
- `BACKGROUND`: true if `--background` present, false otherwise
- `STREAM`: true if `--stream` present
- `TIMEOUT`: value after `--timeout` if present (e.g. `60s`, `2m`)
- `TASK_ID`: value after `--task` if present
- `CONTEXT_ID`: value after `--context` if present

## Process

1. **Check prerequisites**: Verify that `a2a` is installed before proceeding:

   ```bash
   if ! command -v a2a &>/dev/null; then
     echo "Error: 'a2a' CLI not found. Install with:"
     echo "  go install github.com/a2aproject/a2a-go/v2/cmd/a2a@latest"
     exit 1
   fi
   ```

2. **Resolve alias, auth, and timeout**: Resolve the URL, auth params, and timeout from settings:

   ```bash
   URL=$(python3 "${CLAUDE_PLUGIN_ROOT}/scripts/a2a-helper.py" resolve "$URL_OR_ALIAS")
   AUTH_ARGS=()
   while IFS= read -r line; do
     AUTH_ARGS+=("$line")
   done < <(python3 "${CLAUDE_PLUGIN_ROOT}/scripts/a2a-helper.py" auth "$URL")
   SETTINGS_TIMEOUT=$(python3 "${CLAUDE_PLUGIN_ROOT}/scripts/a2a-helper.py" timeout "$URL")
   TIMEOUT_VAL="${TIMEOUT:-${SETTINGS_TIMEOUT:-120s}}"
   ```

3. **Report effective timeout**: Inform the user of the effective timeout before sending:
   > Timeout: `<TIMEOUT_VAL>` (from: `--timeout` flag / settings / default 120s)

4. **Build flags array**:
   - If `BACKGROUND`: add `--immediate`
   - If `STREAM`: add `--stream`
   - If `TIMEOUT_VAL` non-empty: add `--timeout "$TIMEOUT_VAL"`
   - If `TASK_ID`: add `--task "$TASK_ID"`
   - If `CONTEXT_ID`: add `--context "$CONTEXT_ID"`

5. **Send the message**:
   ```bash
   a2a send "$URL" "$MESSAGE" "${FLAGS[@]}" "${AUTH_ARGS[@]}"
   ```

6. **Track the task**: Extract the task ID from the output (look for `id:` or `"id":` field). Always track the task:
   ```bash
   python3 "${CLAUDE_PLUGIN_ROOT}/scripts/a2a-helper.py" session add "$TASK_ID" "$URL" \
     --alias "$URL_OR_ALIAS" --message "$MESSAGE"
   ```

7. **Handle output**: Render the result based on mode (see `### Output` below) and handle failures or `input-required` status.

### Output

- **Blocking** (default): show the full response including artifacts. Parse and render text parts directly.
- **Background**: show the task ID and status. Inform the user they can check progress with the status skill.
- **Streaming**: relay output as it arrives.

If the task fails with a timeout error, suggest retrying with a longer value (e.g. `--timeout 300s`) or increasing `timeout:` in `.claude/a2a.local.md`.

If the task status is `input-required`, prompt the user for the required input and offer to continue
the task by running send again with `--task <task-id>`.

## Example Usage

```bash
# Send a message (blocking — waits for response)
/a2a-send https://demo.a2a-protocol.org "Summarize the latest news about AI"

# Send in background — returns task ID immediately
/a2a-send my-agent --background "Run a long analysis job"

# Continue an existing task by passing --task <task-id>
/a2a-send my-agent --task task_abc123 "Here is the additional context you asked for"
```