> For the complete documentation index, see [llms.txt](https://developer.harness.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.harness.io/harness-platform/use-harness-platform/variables-and-expressions.md).

# Variables & Expressions

{% content-ref url="/pages/CqqTStRBIGfRSOQpFbHd" %}
[Fixed values, runtime inputs, and expressions](/harness-platform/use-harness-platform/variables-and-expressions/runtime-inputs.md)
{% endcontent-ref %}

{% content-ref url="/pages/871488GBDhkFLd84N9cM" %}
[Use runtime input](/harness-platform/use-harness-platform/variables-and-expressions/runtime-input-usage.md)
{% endcontent-ref %}

{% content-ref url="/pages/zyYWsgchmVnnX6htxxVs" %}
[Define variables](/harness-platform/use-harness-platform/variables-and-expressions/add-a-variable.md)
{% endcontent-ref %}

{% content-ref url="/pages/tUiFRZ5SdqvDB97hJdLq" %}
[Use Harness expressions](/harness-platform/use-harness-platform/variables-and-expressions/harness-variables.md)
{% endcontent-ref %}

{% content-ref url="/pages/QlbRH0PbGAXEFMHMYJ6S" %}
[Built-in Variables List](/harness-platform/use-harness-platform/variables-and-expressions/harness-expressions-reference.md)
{% endcontent-ref %}

{% content-ref url="/pages/Wj1vSqbmpKDcVMe2qA1Q" %}
[Branch-scoped build numbers](/harness-platform/use-harness-platform/variables-and-expressions/branch-build-sequence-id.md)
{% endcontent-ref %}

{% content-ref url="/pages/L5U76RlKIAlW738WdQiB" %}
[Use Java string methods](/harness-platform/use-harness-platform/variables-and-expressions/expressions-java-methods.md)
{% endcontent-ref %}

{% content-ref url="/pages/YicqzrwsYg2iNePUV8fW" %}
[Use JSON parser tools and JEXL](/harness-platform/use-harness-platform/variables-and-expressions/expression-v2.md)
{% endcontent-ref %}

{% content-ref url="/pages/wyhUXEl6iYK42MumV3yz" %}
[Output variables with chained pipeline](/harness-platform/use-harness-platform/variables-and-expressions/chained-pipeline-output-variables.md)
{% endcontent-ref %}

{% content-ref url="/pages/tJkzIwxaIgve43MazNsM" %}
[Variables and Expressions FAQ's](/harness-platform/use-harness-platform/variables-and-expressions/variables-and-expressions-faqs.md)
{% endcontent-ref %}