> For the complete documentation index, see [llms.txt](https://docs.zama.org/protocol/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.zama.org/protocol/solidity-guides/v0.10/coprocessor.md).
# coprocessor
### Introduction
**FHEVM Coprocessor** provides the execution service for FHE computations.
It includes a **Coprocessor** service [FHEVM-coprocessor](/protocol/solidity-guides/v0.10/coprocessor/docs/getting_started/fhevm/coprocessor/coprocessor_backend.md). The Coprocessor itself consists of multiple microservices, e.g. for FHE compute, input verify, transaction sending, listenting to events, etc.
### Main features
* An **Executor** service for [FHEVM-native](/protocol/solidity-guides/v0.10/coprocessor/docs/getting_started/fhevm/native/executor.md)
* A **Coprocessor** service for [FHEVM-coprocessor](/protocol/solidity-guides/v0.10/coprocessor/docs/getting_started/fhevm/coprocessor/coprocessor_backend.md)
*Learn more about FHEVM Coprocessor features in the* [*documentation*](/protocol/solidity-guides/v0.10/coprocessor/docs.md)*.*\
### Table of Contents
* [Introduction](#introduction)
* [Main Features](#main-features)
* [Getting Started](#getting-started)
* [Generating Keys](#generating-keys)
* [Coprocessor](#coprocessor)
* [Dependencies](#dependences)
* [Installation](#installation)
* [Services Configuration](#services-configuration)
* [tfhe-worker](#tfhe-worker)
* [cli](#cli)
* [host-listener](#host-listener)
* [gw-listener](#gw-listener)
* [sns-worker](#sns-worker)
* [zkproof-worker](#zkproof-worker)
* [transaction-sender](#transaction-sender)
* [Resources](#resources)
* [Documentation](#documentation)
* [FHEVM Demo](#fhevm-demo)
* [Support](#support)
### Getting started
#### Generating keys
For testing purposes a set of keys can be generated as follows:
```
$ cd fhevm-engine/fhevm-engine-common
$ cargo run generate-keys
```
The keys are stored by default in `fhevm-engine/fhevm-keys`.
#### Coprocessor
**Dependences**
* `docker-compose`
* `rust`
* `sqlx-cli` (install with `cargo install sqlx-cli`)
* `anvil` (for testing, installation manual )
**Installation**
```
$ cd fhevm-engine/coprocessor
$ cargo install --path .
```
**Services Configuration**
**tfhe-worker**
```bash
$ tfhe_worker --help
Usage: tfhe_worker [OPTIONS]
Options:
--run-server
Run the API server
--run-bg-worker
Run the background worker
--generate-fhe-keys
Generate fhe keys and exit
--server-maximum-ciphertexts-to-schedule
Server maximum ciphertexts to schedule per batch [default: 5000]
--server-maximum-ciphertexts-to-get
Server maximum ciphertexts to serve on get_cihpertexts endpoint [default: 5000]
--work-items-batch-size
Work items batch size [default: 10]
--tenant-key-cache-size
Tenant key cache size [default: 32]
--maximimum-compact-inputs-upload
Maximum compact inputs to upload [default: 10]
--maximum-handles-per-input
Maximum compact inputs to upload [default: 255]
--coprocessor-fhe-threads
Coprocessor FHE processing threads [default: 8]
--tokio-threads
Tokio Async IO threads [default: 4]
--pg-pool-max-connections
Postgres pool max connections [default: 10]
--server-addr
Server socket address [default: 127.0.0.1:50051]
--metrics-addr
Prometheus metrics server address [default: 0.0.0.0:9100]
--database-url
Postgres database url. If unspecified DATABASE_URL environment variable is used
--coprocessor-private-key
Coprocessor private key file path. Private key is in plain text 0x1234.. format [default: ./coprocessor.key]
```
```bash
$ cli --help
Usage: cli
Commands:
insert-tenant Inserts tenant into specified database
smoke-test Coprocessor smoke test
help Print this message or the help of the given subcommand(s)
Options:
-h, --help Print help
-V, --version Print version
```
For more details on configuration, please check [Coprocessor Configuration](/protocol/solidity-guides/v0.10/coprocessor/docs/getting_started/fhevm/coprocessor/configuration.md)
**host-listener**
```bash
$ host_listener --help
Usage: host_listener [OPTIONS]
Options:
--url [default: ws://0.0.0.0:8746]
--ignore-tfhe-events
--ignore-acl-events
--acl-contract-address
--tfhe-contract-address
--database-url
--start-at-block Can be negative from last block
--end-at-block
-h, --help Print help
-V, --version Print version
```
**gw-listener**
```bash
$ gw_listener --help
Usage: gw_listener [OPTIONS] --gw-url --input-verification-address --kms-generation-address
Options:
--database-url
--database-pool-size
[default: 16]
--verify-proof-req-database-channel
[default: event_zkpok_new_work]
--gw-url
-i, --input-verification-address
--kms-generation-address
--error-sleep-initial-secs
[default: 1]
--error-sleep-max-secs
[default: 10]
--health-check-port
[default: 8080]
--metrics-addr
Prometheus metrics server address [default: 0.0.0.0:9100]
--health-check-timeout
[default: 4s]
--provider-max-retries
[default: 4294967295]
--provider-retry-interval
[default: 4s]
--log-level
[default: INFO]
--host-chain-id
--get-logs-poll-interval
[default: 1s]
--get-logs-block-batch-size
[default: 100]
--service-name
gw-listener service name in OTLP traces [default: gw-listener]
--catchup-kms-generation-from-block
Can be negative from last processed block
-h, --help
Print help
-V, --version
Print version
```
**transaction-sender**
```bash
$ transaction_sender --help
Usage: transaction_sender [OPTIONS] --input-verification-address --ciphertext-commits-address --multichain-acl-address --gateway-url
Options:
-i, --input-verification-address
-c, --ciphertext-commits-address
-m, --multichain-acl-address
-g, --gateway-url
-s, --signer-type
[default: private-key] [possible values: private-key, aws-kms]
-p, --private-key
-d, --database-url
--database-pool-size
[default: 10]
--database-polling-interval-secs
[default: 1]
--verify-proof-resp-database-channel
[default: event_zkpok_computed]
--add-ciphertexts-database-channel
[default: event_ciphertexts_uploaded]
--allow-handle-database-channel
[default: event_allowed_handle]
--verify-proof-resp-batch-limit
[default: 128]
--verify-proof-resp-max-retries
[default: 6]
--verify-proof-remove-after-max-retries
--add-ciphertexts-batch-limit
[default: 10]
--allow-handle-batch-limit
[default: 10]
--allow-handle-max-retries
[default: 2147483647]
--add-ciphertexts-max-retries
[default: 2147483647]
--error-sleep-initial-secs
[default: 1]
--error-sleep-max-secs
[default: 300]
--txn-receipt-timeout-secs
[default: 10]
--required-txn-confirmations
[default: 0]
--review-after-unlimited-retries
[default: 30]
--provider-max-retries
[default: 4294967295]
--provider-retry-interval
[default: 4s]
--health-check-port
[default: 8080]
--metrics-addr
Prometheus metrics server address [default: 0.0.0.0:9100]
--health-check-timeout
[default: 4s]
--log-level
[default: INFO]
--gas-limit-overprovision-percent
[default: 120]
--graceful-shutdown-timeout
[default: 8s]
--service-name
service name in OTLP traces [default: txn-sender]
--metric-host-txn-latency
Prometheus metrics: coprocessor_host_txn_latency_seconds [default: 0.1:60.0:0.1]
--metric-zkproof-txn-latency
Prometheus metrics: coprocessor_zkproof_txn_latency_seconds [default: 0.1:60.0:0.1]
-h, --help
Print help
-V, --version
Print version
```
When using the `private-key` signer type, the `-p, --private-key ` option becomes mandatory.
When using the `aws-kms` signer type, standard `AWS_*` environment variables are supported, e.g.:
* **AWS\_REGION**
* **AWS\_ACCESS\_KEY\_ID** (i.e. username)
* **AWS\_SECRET\_ACCESS\_KEY** (i.e. password)
* etc.
### Resources
#### Documentation
Full, comprehensive documentation is available here: .
#### FHEVM Demo
A complete demo showcasing an integrated FHEVM blockchain and KMS (Key Management System) is available here: .
### Support
🌟 If you find this project helpful or interesting, please consider giving it a star on GitHub! Your support helps to grow the community and motivates further development.
[](https://github.com/zama-ai/fhevm/)
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