Add dTelecom action provider for decentralized voice services

[fffilimonov]

Description

Adds a new dTelecom action provider for decentralized real-time voice infrastructure (WebRTC, speech-to-text, text-to-speech) with x402 micropayments, plus a complete voice agent example.

dTelecom provides decentralized WebRTC infrastructure — SFU routing, STT, and TTS — paid per-use with USDC via the x402 payment protocol. This provider lets AI agents create voice sessions, manage credits, and build real-time voice applications.

Action Provider — 12 actions

Action	Description
buy_credits	Buy credits with USDC via x402
get_account	Check credit balance and limits
get_transactions	List credit transactions
get_sessions	List active/past sessions
create_agent_session	Bundled WebRTC + STT + TTS session
extend_agent_session	Extend a bundled session
create_webrtc_token	Standalone WebRTC token
extend_webrtc_token	Extend WebRTC token
create_stt_session	Standalone speech-to-text session
extend_stt_session	Extend STT session
create_tts_session	Standalone text-to-speech session
extend_tts_session	Extend TTS session

Voice Agent Example

Standalone example (typescript/examples/dtelecom-voice-agent/):

1. Creates a CDP wallet on Base mainnet
2. Auto-purchases dTelecom credits via x402 if balance is low
3. Creates a bundled voice session (WebRTC + STT + TTS)
4. Starts a server-side voice agent with OpenAI LLM
5. Serves a browser client on localhost:3000 for real-time voice conversation

Files Changed

• typescript/agentkit/src/action-providers/dtelecom/ — provider, schemas, tests, README (5 files)
• typescript/agentkit/src/action-providers/index.ts — barrel export
• typescript/agentkit/package.json — added @dtelecom/x402-client dependency
• typescript/examples/dtelecom-voice-agent/ — example (6 files)
• README.md — protocol logo
• assets/protocols/dtelecom.svg — logo
• typescript/.changeset/dtelecom-voice-provider.md — changeset

Tests

Unit tests: 16 tests covering all 12 actions, network support, and error propagation.

Chatbot: typescript/examples/dtelecom-voice-agent/voice-agent.ts
Network: Base Mainnet
Setup: CDP wallet funded with USDC

Prompt: (voice) "How are you?"

Agent: "I'm doing well, thank you! How can I help you today?"

Prompt: (voice) "Tell me more about Coinbase"

Agent: "Coinbase is one of the largest cryptocurrency exchanges..."

Prompt: (voice) "And what about dTelecom?"

Agent: "dTelecom is a decentralized telecommunications network that provides
real-time communication infrastructure..."

End-to-end voice conversation worked with ~2s latency (STT → LLM → TTS).

Checklist

• Added documentation to all relevant README.md files
• Added a changelog entry

[cb-heimdall]

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