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google__adk-docs/docs/agents/workflow-agents/parallel-agents.md
Amaad Martin c75e61f5f3 docs: normalize Typescript to TypeScript across the site (#2079)
The site rendered one language under two names. Tab labels were split
137 `TypeScript` / 53 `Typescript`, with three pages carrying both
spellings at once (custom-agents.md 7/7, patterns.md 1/7,
function-tools.md 4/1), and the language-support badges were split 67/18
the same way. Because pymdownx.tabbed slugifies tab labels to lowercase,
both variants rendered and linked fine, so no link check or build warning
ever flagged it -- it was visible only to readers, as two names for one
SDK.

Every user-visible occurrence is normalized to `TypeScript`, plus the two
inconsistencies that turned up while doing it. 80 changed lines, accounted
for exactly:

  53  tab label       === "Typescript"            -> === "TypeScript"
  18  badge span      lst-typescript">Typescript  -> TypeScript
   3  prose mention   cloud-run.md, mcp-tools.md, workflows/patterns.md
   2  api-reference/index.md card heading and link text
   1  badge div attr  title="...Python and Typescript."
   1  mkdocs.yml nav  Typescript ADK              -> TypeScript ADK
   1  code fence      ```javascript -> ```typescript on a .ts include
   1  artifacts/index.md closing summary sentence
  ---
  80

The first six rows are pure casing: 78 lines that differ from their
originals by nothing but `Typescript` -> `TypeScript`. The last two are
not, and are the reason this is not a `sed`:

llm-agents.md:872 fenced `--8<-- ".../capital_agent.ts"` as ```javascript.
It was the only javascript-fenced `.ts` include in docs/ (the other 189
TypeScript fences are correct), and it cost that one snippet its
TypeScript highlighting.

artifacts/index.md:1084 closed the page by naming languages and got the
list wrong. It described reaching the artifact methods "using Python's
context objects or directly interacting with the `BaseArtifactService` in
Java" -- a two-language enumeration at the end of a page that carries
Python, TypeScript, Go, Java and Kotlin tabs (11/10/10/10/11), and one
that contradicts :556, which correctly names four of them. The
enumeration is dropped rather than extended: the sentence now describes
the two ways to reach these methods -- through the context object, or
through `BaseArtifactService` -- which is what the page actually teaches
and does not rot when a sixth language is added.

docs/api-reference/index.md is included even though the rest of
docs/api-reference/ is generated output that must not be touched. That
tree holds 3,140 generated HTML files and exactly one hand-authored page:
this one. It is Markdown, it is the only api-reference entry mkdocs.yml
lists as `.md` rather than `index.html` (:272, :441), it uses Material
`grid cards` and `:fontawesome-*:` shortcodes, and it carries a
`CONTRIBUTORS:` note citing issues #1716 and #1717. Its TypeScript card
already said "TypeScript" twice in its body text while its heading and
link text said "Typescript"; those two are now consistent with the body.
No generated file is modified.

Not in this change: the broken `SseConnectionParams` sample in
mcp-tools.md (docs-ts/p6c-mcp-ts-sample) and the `@google/adk` example
version bumps (docs-ts/p6b-example-versions). Only the casing of the
prose line above that sample is touched here.

Verified: `mkdocs build` exits 0 with an empty warning set on both main
and this branch, and the two warning sets are identical. A rendered
before/after diff of the whole site shows every `__tabbed_*` id, every
tab radio id and every heading anchor unchanged. Zero `=== "Typescript"`
and zero `lst-typescript">Typescript` remain anywhere in the repo.

Co-authored-by: Amaad Martin <amaadmartin@google.com>
2026-08-05 15:58:49 -07:00

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Markdown

# Parallel template workflow agent
<div class="language-support-tag">
<span class="lst-supported">Supported in ADK</span><span class="lst-python">Python v0.1.0</span><span class="lst-typescript">TypeScript v0.2.0</span><span class="lst-go">Go v0.1.0</span><span class="lst-java">Java v0.2.0</span>
</div>
The ***ParallelAgent*** class is a [template workflow](/agents/workflow-agents/)
agent that executes its sub-agents concurrently. This execution strategy can
dramatically speed up workflows where two or more tasks can be performed
independently. For scenarios prioritizing speed and involving independent,
resource-intensive tasks, this templated workflow facilitates parallel
execution, which can significantly reduce overall processing time. When using
this workflow type, it is important that each sub-agent can operate without
depending on the other sub-agents. This workflow type is particularly beneficial
for operations like multi-source data retrieval or heavy computations, where
parallelization yields substantial performance gains.
As with other templated workflows, the execution of a ***ParallelAgent*** object
is not controlled by an AI model, and is deterministic in how it executes its
sub-agents. The sub-agents specified in the parallel execution set may or may
not utilize AI models, but the overall execution of those sub-agents is
ultimately managed by the ***ParallelAgent*** object you define.
!!! note "Alternative: graph-based workflows"
Starting in ADK 2.0 for Python and Go, templated workflows have been superseded
by more flexible workflow structures, including
[graph-based workflows](/graphs/) and
[dynamic workflows](/graphs/dynamic/).
### How it works
When the `ParallelAgent`'s `run_async()` method is called:
1. **Concurrent Execution:** It initiates the `run_async()` method of *each* sub-agent present in the `sub_agents` list *concurrently*. This means all the agents start running at (approximately) the same time.
2. **Independent Branches:** Each sub-agent operates in its own execution branch. There is ***no* automatic sharing of conversation history or state between these branches** during execution.
3. **Result Collection:** The `ParallelAgent` manages the parallel execution and, typically, provides a way to access the results from each sub-agent after they have completed (e.g., through a list of results or events). The order of results may not be deterministic.
### Independent Execution and State Management
It's *crucial* to understand that sub-agents within a `ParallelAgent` run independently. If you *need* communication or data sharing between these agents, you must implement it explicitly. Possible approaches include:
* **Shared `InvocationContext`:** You could pass a shared `InvocationContext` object to each sub-agent. This object could act as a shared data store. However, you'd need to manage concurrent access to this shared context carefully (e.g., using locks) to avoid race conditions.
* **External State Management:** Use an external database, message queue, or other mechanism to manage shared state and facilitate communication between agents.
* **Post-Processing:** Collect results from each branch, and then implement logic to coordinate data afterwards.
![Parallel Agent](/assets/parallel-agent.png){: width="600"}
### Full Example: Parallel Web Research
Imagine researching multiple topics simultaneously:
1. **Researcher Agent 1:** An `LlmAgent` that researches "renewable energy sources."
2. **Researcher Agent 2:** An `LlmAgent` that researches "electric vehicle technology."
3. **Researcher Agent 3:** An `LlmAgent` that researches "carbon capture methods."
```py
ParallelAgent(sub_agents=[ResearcherAgent1, ResearcherAgent2, ResearcherAgent3])
```
These research tasks are independent. Using a `ParallelAgent` allows them to run concurrently, potentially reducing the total research time significantly compared to running them sequentially. The results from each agent would be collected separately after they finish.
???+ "Full Code"
=== "Python"
```py
--8<-- "examples/python/snippets/agents/workflow-agents/parallel_agent_web_research.py:init"
```
=== "TypeScript"
```typescript
--8<-- "examples/typescript/snippets/agents/workflow-agents/parallel_agent_web_research.ts:init"
```
=== "Go"
```go
--8<-- "examples/go/snippets/agents/workflow-agents/parallel/main.go:init"
```
=== "Java"
```java
--8<-- "examples/java/snippets/src/main/java/agents/workflow/ParallelResearchPipeline.java:full_code"
```