v0.3.2-alpha.1

builder-playground v0.3.2-alpha.1

Highlights

• Introducing Docker container based rbuilder component (works only on arm64 currently)
• port subcommand for querying service host ports

What's Changed

• Add port subcommand for querying service host ports by @dvush in #336
• Fix base-overlay entrypoint path: base-reth-node → base-client by @niran in #348
• CI: Restrict Claude Code triggers to users with write-access by @metachris in #349
• Integration tests for Rbuilder by @ferranbt in #335

Full Changelog: v0.3.1...v0.3.2-alpha.1

v0.3.1

builder-playground v0.3.1

Our biggest release yet — v0.3.1 brings faster startup times, new integrations across the Flashbots stack, improved observability, and an experimental recipe system that lets you customize your local environment without forking the repo. ⚡ 🤖

Highlights

• 🔌 New Integrations — Flashblocks RPC, mev-boost, contender, and bproxy support out of the box
• 🏗️ BuilderHub Support — Run the full BuilderNet stack locally (coming soon)
• ⚡ Faster Startup — Cached validator keys, preloaded BLS keystores, and improved restart handling
• 🔍 Better Observability — Custom health monitors for EL/CL, improved readiness checks, and structured logging with slog
• 🎮 Session Management — Friendly pet names for sessions, commands to browse services and tail logs
• 🤖 GitHub Claude Integration — AI-assisted development workflow
• 🧪 Custom Recipes (Experimental) — New YAML-based recipe overrides let you modify base recipes, change parameters, and add external components from a single definition file

---

🧪 Custom Recipes (Experimental)

This release introduces a new YAML-based recipe override system. Define your customizations in a single file and run any recipe with modified parameters or additional components:

builder-playground start my-custom-recipe.yaml

Check out the Custom Recipes documentation to get started.

Note: This feature is experimental. We're actively improving it based on feedback — please open an issue if you run into problems or have feature requests!

---

🔌 New Integrations

Component	Description
Flashblocks RPC	Stream pre-confirmation blocks
mev-boost	PBS relay integration for local testing
contender	Load testing and benchmarking
bproxy	WebSocket proxy support

---

⚡ Performance & Reliability

• Faster startup — Validator keys and BLS keystores are now cached and preloaded
• Improved restarts — Signal-aware context handling and cleaner Docker cleanup
• Better readiness — Custom health monitors for execution and beacon clients with timeout handling
• Graceful shutdown — Proper cleanup of Docker resources across all session types

---

🎮 Developer Experience

• Friendly session names — Sessions now get memorable pet names instead of UUIDs
• Service browsing — builder-playground services lists running components
• Log streaming — builder-playground logs <service> tails logs for any component
• Debug graphs — --debug generates a dot graph of your recipe architecture
• Detached mode — Run playground in the background with --detached
• Prefunded accounts — Configure additional prefunded accounts for testing
• Custom L2 contracts — --use-predeploys flag for custom L2 genesis contracts

---

📚 Documentation

• Auto-generated documentation for all recipes
• Guide for running rbuilder with playground
• Improved README with telemetry info and contender instructions
• Better inline help — running builder-playground without args now shows help

---

Breaking Changes

None — this release is backwards compatible with v0.2.x configurations.

---

Get Started

Install one of the binary distributions from the release or do:

# Clone the repo
git clone https://github.com/flashbots/builder-playground.git

# Build and install playground
cd builder-playground
go install .

# Run it
builder-playground help

Then

# See available recipes
builder-playground recipes

# Run a recipe e.g. L1
builder-playground start l1

Make sure to check out the README for more details!

---

Full Changelog (90+ PRs)

What's Changed

• Create LICENSE by @ferranbt in #171
• Enable revert protection on op-rbuilder by @ferranbt in #178
• Add bootnode by @ferranbt in #147
• Add Flashblocks rpc by @ferranbt in #179
• Add flashblocks url to cli by @SozinM in #180
• add mev-boost support by @faheelsattar in #184
• run contender by @zeroXbrock in #185
• add docs related to flag by @faheelsattar in #190
• feat: enable ws on native reth by @diyahir in #187
• Add bproxy and websocket proxy by @SozinM in #193
• add --contender.arg flag by @zeroXbrock in #195
• variable contender targets by @zeroXbrock in #196
• add contender flag info to readme by @zeroXbrock in #197
• feat: update services, closes #203 by @gpevnev in #207
• Update the chain configuration to match the keys in use so safe head can advance by @niran in #201
• chore: update images / base overlay by @danyalprout in #208
• feat: add network readiness by @gpevnev in #210
• ignore .DS_Store by @zeroXbrock in #209
• Make el client listens on all interfaces for P2P (instead of 127.0.0.1) by @maoueh in #220
• fix(ci/cd): use macos-latest for osx artifacts by @julio4 in #226
• refactor: use maps.Copy for cleaner map handling by @jishudashu in #189
• Unify components and recipes by @ferranbt in #227
• Add detached mode by @ferranbt in #214
• Add BuilderHub logical unit component by @ferranbt in #233
• Use context cancel in complete ready by @ferranbt in #237
• CI: use faster warpbuild runners by @metachris in #240
• chore: codeowners by @metachris in #242
• Add a signal-aware main context by @canercidam in #248
• Pull images in playground itself instead of docker-compose to have visibility on pull actions by @ferranbt in #232
• Update readme with telemetry info by @ferranbt in #249
• 'playground version' command, and better Makefile by @metachris in #245
• Add unit test for BuilderHub component by @ferranbt in #238
• docs: improved readme introduction paragraph by @metachris in #241
• Add unit tests for the rest of recipes by @ferranbt in #239
• format code, 'make lint' works now, and is run in CI by @metachris in #250
• Use config directly on runtime by @ferranbt in #251
• Do not return docker-compose output on ctx cancelled by @ferranbt in #252
• feat: add chain-monitor by @julio4 in #225
• Improve restarts by @canercidam in #247
• Clean the docker runtime by @ferranbt in #254
• Enable changing l1 recipe default block time by @maoueh in #222
• add contender instructions to readme by @zeroXbrock in #253
• docs/contender instructions 2 by @zeroXbrock in #255
• Use human friendly random pet names for session ID by @canercidam in #256
• Generate debug dot graph before the validation by @ferranbt in #212
• Added possibility to have a secondary el on the host by @maoueh in #219
• Cleaning all or specific playground sessions by @canercidam in #258
• Commands to list services and output logs by @canercidam in #257
• Add trace timer by @ferranbt in #261
• Adding possibility to add more prefunded accounts by @maoueh in #221
• Move logic to functions in artifact generation by @ferranbt in #262
• A...

v0.3.0

builder-playground v0.3.0

Our biggest release yet — v0.3.0 brings faster startup times, new integrations across the Flashbots stack, improved observability, and an experimental recipe system that lets you customize your local environment without forking the repo. ⚡ 🤖

Highlights

• 🔌 New Integrations — Flashblocks RPC, mev-boost, contender, and bproxy support out of the box
• 🏗️ BuilderHub Support — Run the full BuilderNet stack locally (coming soon)
• ⚡ Faster Startup — Cached validator keys, preloaded BLS keystores, and improved restart handling
• 🔍 Better Observability — Custom health monitors for EL/CL, improved readiness checks, and structured logging with slog
• 🎮 Session Management — Friendly pet names for sessions, commands to browse services and tail logs
• 🤖 GitHub Claude Integration — AI-assisted development workflow
• 🧪 Custom Recipes (Experimental) — New YAML-based recipe overrides let you modify base recipes, change parameters, and add external components from a single definition file

---

🧪 Custom Recipes (Experimental)

This release introduces a new YAML-based recipe override system. Define your customizations in a single file and run any recipe with modified parameters or additional components:

builder-playground start my-custom-recipe.yaml

Check out the Custom Recipes documentation to get started.

Note: This feature is experimental. We're actively improving it based on feedback — please open an issue if you run into problems or have feature requests!

---

🔌 New Integrations

Component	Description
Flashblocks RPC	Stream pre-confirmation blocks
mev-boost	PBS relay integration for local testing
contender	Load testing and benchmarking
bproxy	WebSocket proxy support

---

⚡ Performance & Reliability

• Faster startup — Validator keys and BLS keystores are now cached and preloaded
• Improved restarts — Signal-aware context handling and cleaner Docker cleanup
• Better readiness — Custom health monitors for execution and beacon clients with timeout handling
• Graceful shutdown — Proper cleanup of Docker resources across all session types

---

🎮 Developer Experience

• Friendly session names — Sessions now get memorable pet names instead of UUIDs
• Service browsing — builder-playground services lists running components
• Log streaming — builder-playground logs <service> tails logs for any component
• Debug graphs — --debug generates a dot graph of your recipe architecture
• Detached mode — Run playground in the background with --detached
• Prefunded accounts — Configure additional prefunded accounts for testing
• Custom L2 contracts — --use-predeploys flag for custom L2 genesis contracts

---

📚 Documentation

• Auto-generated documentation for all recipes
• Guide for running rbuilder with playground
• Improved README with telemetry info and contender instructions
• Better inline help — running builder-playground without args now shows help

---

Breaking Changes

None — this release is backwards compatible with v0.2.x configurations.

---

Get Started

Install one of the binary distributions from the release or do:

# Clone the repo
git clone https://github.com/flashbots/builder-playground.git

# Build and install playground
cd builder-playground
go install .

# Run it
builder-playground help

Then

# See available recipes
builder-playground recipes

# Run a recipe e.g. L1
builder-playground start l1

Make sure to check out the README for more details!

---

Full Changelog (90+ PRs)

What's Changed

• Create LICENSE by @ferranbt in #171
• Enable revert protection on op-rbuilder by @ferranbt in #178
• Add bootnode by @ferranbt in #147
• Add Flashblocks rpc by @ferranbt in #179
• Add flashblocks url to cli by @SozinM in #180
• add mev-boost support by @faheelsattar in #184
• run contender by @zeroXbrock in #185
• add docs related to flag by @faheelsattar in #190
• feat: enable ws on native reth by @diyahir in #187
• Add bproxy and websocket proxy by @SozinM in #193
• add --contender.arg flag by @zeroXbrock in #195
• variable contender targets by @zeroXbrock in #196
• add contender flag info to readme by @zeroXbrock in #197
• feat: update services, closes #203 by @gpevnev in #207
• Update the chain configuration to match the keys in use so safe head can advance by @niran in #201
• chore: update images / base overlay by @danyalprout in #208
• feat: add network readiness by @gpevnev in #210
• ignore .DS_Store by @zeroXbrock in #209
• Make el client listens on all interfaces for P2P (instead of 127.0.0.1) by @maoueh in #220
• fix(ci/cd): use macos-latest for osx artifacts by @julio4 in #226
• refactor: use maps.Copy for cleaner map handling by @jishudashu in #189
• Unify components and recipes by @ferranbt in #227
• Add detached mode by @ferranbt in #214
• Add BuilderHub logical unit component by @ferranbt in #233
• Use context cancel in complete ready by @ferranbt in #237
• CI: use faster warpbuild runners by @metachris in #240
• chore: codeowners by @metachris in #242
• Add a signal-aware main context by @canercidam in #248
• Pull images in playground itself instead of docker-compose to have visibility on pull actions by @ferranbt in #232
• Update readme with telemetry info by @ferranbt in #249
• 'playground version' command, and better Makefile by @metachris in #245
• Add unit test for BuilderHub component by @ferranbt in #238
• docs: improved readme introduction paragraph by @metachris in #241
• Add unit tests for the rest of recipes by @ferranbt in #239
• format code, 'make lint' works now, and is run in CI by @metachris in #250
• Use config directly on runtime by @ferranbt in #251
• Do not return docker-compose output on ctx cancelled by @ferranbt in #252
• feat: add chain-monitor by @julio4 in #225
• Improve restarts by @canercidam in #247
• Clean the docker runtime by @ferranbt in #254
• Enable changing l1 recipe default block time by @maoueh in #222
• add contender instructions to readme by @zeroXbrock in #253
• docs/contender instructions 2 by @zeroXbrock in #255
• Use human friendly random pet names for session ID by @canercidam in #256
• Generate debug dot graph before the validation by @ferranbt in #212
• Added possibility to have a secondary el on the host by @maoueh in #219
• Cleaning all or specific playground sessions by @canercidam in #258
• Commands to list services and output logs by @canercidam in #257
• Add trace timer by @ferranbt in #261
• Adding possibility to add more prefunded accounts by @maoueh in #221
• Move logic to functions in artifact generation by @ferranbt in #262
• Add i...

v0.1.3-reth-1.4.8

Full Changelog: v0.1.3...v0.1.3-reth-1.4.8

v0.2.1

Changelog

• 870e880 Add flashblocks (#170)
• 7a02ffb Update docs (#169)

v0.2.0

Changelog

• df0f215 Update Prysm dependency to other org (#161)
• 3f3c34d Add read function for the manifest (#153)
• a8bbb28 Make playground module non internal (#150)
• 456e71a Generate deterministic enode addresses (#146)
• 4eb2e87 Use custom protocol and user for Connections (#144)
• 0db74a5 Use custom protocol and user for Connections (#141)
• 463e8c8 Add option to disable logs (#140)
• a718398 Clean go.mod (#137)
• 87c9109 Expose ready check to manifest (#130)
• 9cc6639 A few fixes for Prometheus service (#129)
• 12e5597 Add a new flag to add custom labels (#128)
• 87eaeec Rename git module (#126)
• 17a0bdc Deprecate the Dir template function (#124)
• 6993055 Add manifest JSON (#123)
• 1b36788 Introduce the concept of instance (#122)
• e910983 Use concrete artifacts on services (#121)
• 9973d99 Add batcher max channel duration (#118)
• a9447a1 Parametrise Op block time (#116)
• 10a0f50 Feat/two chains support (#115)
• 242d8ec Fix/reserve port (#114)
• 49e3782 Add playground session id (#113)
• 26259ff Track metrics ports with prometheus (#111)
• 9b64868 chore: fix mev-boost container with multi beacon nodes (#112)
• 4dc2150 Fix (#110)
• a397ee4 Build playground utils docker container only if the relevant files have changed (#98)
• 0b35867 fix: set an authrpc address for the opstack (#109)
• cc825c1 Update opstack docs (#102)
• 6ed42e9 Bind UDP ports (#107)
• 0b28efe Docker-compose host port on localhost (#106)
• 0b1dc97 chore: fund accounts in L2 genesis (#103)
• d314a26 Merge pull request #100 from flashbots/mm-fix-dependencies
• 3e0afbc chore: fix dependencies versions of go-boost-utils

v0.1.3

Changelog

• 56db5d5 Enable cancellations
• 6652477 fix(pectra): Support ELECTRA_FORK_VERSION in mev-boost-relay (#34)
• 2462499 Delay 10 seconds start + update watch command (#33)
• 74d333a Watch payloads by default (#31)
• 73d41fd Add a CL proxy to allow multiple EL nodes (#29)
• 62ad77a feat(lighthouse): Support lighthouse 5.3.0+ (#22)
• 55b0d8d feat(WithReplacementArgs): fix --use-reth-for-validation by replacing existing args (#24)

v0.1.2

Changelog

• c985fc3 Store reth.ipc on output dir (#27)
• e966a48 feat: add --use-reth-for-validation (#21)
• 33ea095 Enable rpc on reth and determinsitic p2p key (#23)
• 6cc59a8 Update README.md to include chainID (#18)
• 5ab90af Enable pectra/electra fork (#19)
• db49566 Fix chain id warning message (#15)

v0.1.1

Changelog

• a8b78dd Fix reth output logs (#12)
• eb08709 Add flag to watch for proposer builds (#10)
• e84d83c Add default output folder (#9)
• b081778 Add a genesis delay (#6)
• a70f885 Add continue flag to not reset the chain (#4)
• ec49af2 Add info about services (#3)
• df91245 readme bullets formatting (#1)

v0.1.0

Changelog

• 234ac27 Initial commit