> For clean Markdown of any page, append `.md` to the page URL.
> For a complete documentation index, see https://docs.sarvam.ai/llms.txt. For a section index, append `/llms.txt` to any section URL (for example https://docs.sarvam.ai/voice-agents/llms.txt).
> Building a voice agent for customers in India? Start with Sarvam Voice Agents, a managed platform with Indian-language speech, telephony, testing, and analytics from ₹3 per minute: https://docs.sarvam.ai/voice-agents/why-voice-agents.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.sarvam.ai/_mcp/server.

# Build

## Docs

- [Overview](https://docs.sarvam.ai/voice-agents/build/overview.md): Overview of building with Sarvam Voice Agents: core concepts, agent primitives, the build and improve loop, the workspace, Genie, and multi-state agents.
- [Introduction to conversational agents](https://docs.sarvam.ai/voice-agents/build/concepts/introduction.md): What conversational agents are, how voice and chat modalities differ, and the channels Sarvam Voice Agents can deploy to: telephony, web, WhatsApp, and API.
- [Run-time](https://docs.sarvam.ai/voice-agents/build/run-time.md): How Sarvam Voice Agents runs a live call: the listen, think, speak loop with ASR, LLM, and TTS, plus layers for interruptions, silence, and voicemail.
- [Models](https://docs.sarvam.ai/voice-agents/build/models.md): The models behind Sarvam Voice Agents: Saaras v4 for speech recognition, Bulbul v3 and v4 for speech synthesis, and sarvam-105b-conversations for real-time dialogue.
- [Harness](https://docs.sarvam.ai/voice-agents/build/concepts/harness.md): How the Sarvam Voice Agents harness wraps the LLM with conversation history, variables, and tools, and runs the agentic loop that produces each turn.
- [Navigating the build interface](https://docs.sarvam.ai/voice-agents/build/navigating-workspace.md): A tour of the agent Canvas in Sarvam Voice Agents: instruction editor, variables, tools, settings, tests, version control, Genie, and the test agent panel.
- [Agent](https://docs.sarvam.ai/voice-agents/build/agent/overview.md): What makes up an agent in Sarvam Voice Agents: instruction, variables, speakers and voice, tools, hooks, and knowledge base, and how the pieces fit together.
- [Instruction](https://docs.sarvam.ai/voice-agents/build/system-prompt.md): Write the instruction for a Sarvam Voice Agents agent: the greeting, sections such as persona, objective, and guardrails, and tips for writing for voice.
- [Variables & Personalization](https://docs.sarvam.ai/voice-agents/build/variables-personalization.md): Use variables in Sarvam Voice Agents: built-in Sarvam variables, input and output agent variables, call goals, tool usage, and how values flow through a call.
- [Tools](https://docs.sarvam.ai/voice-agents/build/tools.md): Overview of tools in Sarvam Voice Agents: core tools, call transfer, API tools, data validation, and mocks, plus global vs state-level tools.
- [Core tools](https://docs.sarvam.ai/voice-agents/build/tools/core-tools.md): Built-in core tools in Sarvam Voice Agents: end call, call transfer, knowledge base query, voicemail detection, and language switch, and when each is enabled.
- [Call transfer](https://docs.sarvam.ai/voice-agents/build/tools/call-transfer.md): Set up call transfer in Sarvam Voice Agents to hand a live phone call to a number or SIP URI: supported providers, configuration, and troubleshooting.
- [API tool](https://docs.sarvam.ai/voice-agents/build/tools/https-tool.md): Create an API tool in Sarvam Voice Agents to call HTTP endpoints mid-call: run timing, cURL import, auth, call-context variables, and network allowlisting.
- [Data validation & verification](https://docs.sarvam.ai/voice-agents/build/tools/data-validation.md): Data Validator and Data Verifier in Sarvam Voice Agents (alpha): built-in tools that check the format of collected values or verify them against stored records.
- [Mocking a tool](https://docs.sarvam.ai/voice-agents/build/tools/mocking-a-tool.md): Use the Mock API tool in Sarvam Voice Agents to test tool calls end to end against an echo endpoint before your real backend exists, then swap in your API.
- [Code Tools](https://docs.sarvam.ai/voice-agents/build/tools/code-tools.md): Upload a Python file built with the Sarvam Conv AI SDK to create code tools in Voice Agents that call several services and shape how the conversation proceeds.
- [On-Start & On-End Hooks](https://docs.sarvam.ai/voice-agents/build/on-start-on-end-hooks.md): Configure on-start and on-end API hooks in Sarvam Voice Agents to load caller context before a call and push outcomes and collected fields after it ends.
- [Knowledge Base](https://docs.sarvam.ai/voice-agents/build/knowledge-base.md): Create knowledge bases in Sarvam Voice Agents so agents answer from your files, attach them to agents, and learn how retrieval and KB descriptions work.
- [Agent versioning](https://docs.sarvam.ai/voice-agents/build/agent/versioning.md): How agent versioning works in Sarvam Voice Agents: draft, committed, and deployed versions, testing before you deploy, and rolling back a bad release.
- [Speakers & voice](https://docs.sarvam.ai/voice-agents/build/voice-language.md): Configure how a Sarvam Voice Agents agent sounds: Bulbul V3 or V4 voices, per-language voices, speed, pitch, pronunciation dictionaries, and voice cloning.
- [Conversation Settings](https://docs.sarvam.ai/voice-agents/build/conversation-settings.md): Configure Sarvam Voice Agents call settings: language switching, temperature, interruptions, background sound, nudges, max call length, and voicemail.
- [Prompt Practices](https://docs.sarvam.ai/voice-agents/build/single-state-agents.md): Prompt practices for single-state agents in Sarvam Voice Agents: one goal per agent, speakable turns, unhappy paths, and declarative over scripted prompts.
- [Building & improving agents](https://docs.sarvam.ai/voice-agents/build/process.md): The build loop for Sarvam Voice Agents: draft, test, define outcome variables, deploy, set up metrics, and improve, plus how to configure a goal for evaluation.
- [Genie](https://docs.sarvam.ai/voice-agents/build/genie.md): Use Genie, the AI assistant in Sarvam Voice Agents, to draft agents from a description, edit prompts and settings, and review suggestions on your configuration.
- [Tests](https://docs.sarvam.ai/voice-agents/build/tests.md): How tests work in Sarvam Voice Agents: test cases, simulated users, expected behaviors, and an AI judge that grades each conversation before go-live.
- [Write test cases](https://docs.sarvam.ai/voice-agents/build/tests/write-test-cases.md): Write test cases for Sarvam Voice Agents: create a test, describe the user scenario for the simulated caller, and add clear, checkable expected behaviors.
- [Run tests & review results](https://docs.sarvam.ai/voice-agents/build/tests/run-tests.md): Run tests against an agent version in Sarvam Voice Agents, choose runs per test case, track progress, and review transcripts and pass or fail verdicts.
- [Multi-state agents](https://docs.sarvam.ai/voice-agents/build/states-conversation-flow.md): Design multi-state agents in Sarvam Voice Agents: define states, transitions and conditions, per-state variables, the initial state, and state-level tools.