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Creating a New Adapter for Amp ProjectPublic

The user wanted to create a new adapter for a project called Amp using the existing framework. The assistant helped by understanding the project structure, creating a stub adapter with failing tests, then fully implementing the adapter with incremental commits. The final outcome was a fully working adapter passing all tests without causing regressions.

Agent

Amp

Model

Claude Opus 4.6

Shared

Feb 21, 11:51 AM

Messages462

hi amp, how's it going?

hi!

Hey! Going well, thanks 😊 How can I help you today?

okay, can you get a sense of how this project works? we're gonna create a new adapter for amp, using amp :)

Readtraces

Readdocs

Readadding-agents.md

Let me explore the project to understand the architecture, especially around adapters!

Readadapters

Readagent.ts

Readadapter.ts

Readindex.ts

Readclaude-code

Readtypes.ts

Now let me look at an existing adapter and the registry to understand the full pattern:

Readv1.ts

Ran command

Now let me look at the Claude Code adapter as a reference, and check where Amp stores its session data:

Ran command

Readconfig.ts

Ran command

Searched web

Now let me find out where Amp stores its thread/session data:

Ran command

Now I have a great picture of the project. Here's what I've learned:

Amp stores data at ~/.local/share/amp/:

history.jsonl — one line per user prompt with text and cwd
threads/T-{uuid}.json — full thread JSON with messages (user, assistant), tool calls, thinking blocks, model info, timestamps, usage stats
session.json — current session state (last thread ID, agent mode)

To build the adapter, we need to:

Add 'amp' to AgentId in packages/shared/src/agent.ts and cli/src/types.ts
Add amp storage path in cli/src/config.ts
Create cli/src/adapters/amp/v1.ts — parse the thread JSON files + history.jsonl
Register it in cli/src/adapters/index.ts

The thread JSON format is rich — messages have role, content arrays with text, thinking, and tool_use blocks, plus usage with model info. Very similar structure to Claude Code's format, which makes mapping to TraceEvent types straightforward.

Ready to start building it! Want me to go ahead?

Let's create a worktree and project file (see others in @docs/projects ) and let's go!

Used Skill

Readprojects

Readshare-to-traces-skills.md

Ran command

Now let me create the worktree and project file:

Ran command

Readshare-to-traces-skills.md

Worktree is ready. Now let me look at an example project file for format reference, then create ours:

Ran command

Now let me look at the Amp thread JSON format more closely to understand what we're parsing:

Ran command

Now let me check the tool_result format and the history.jsonl format:

Oh, sorry to interrupt, but you should study the adapter interface and probably create a stub with failing tests, and then proceed. If that's what you had planned, sorry for interrupting, but just wanted to clarify.

Listed

Readgemini-cli

No worries, that's exactly the right approach! Let me look at existing tests for the pattern, then create the project file + stub + failing tests.

Listed

Readadapters.test.ts

Readv1.ts

Readadapter-validation.ts

Readfixture

Now let me check the test helper and the fixture directory structure:

Readv1.ts

Readpi

Now I have everything I need. Let me look at the Pi adapter too since it's the newest and likely the cleanest pattern to follow (it also reads JSON files like Amp):

Now I have all the context. Let me create everything in the worktree — project file, fixture, stub adapter, and failing tests:

Now let me create the fixture, stub adapter, register it, and write failing tests — all in the worktree:

Now create the empty thread fixture (edge case):

Now add the history.jsonl fixture:

Editedagent.ts

Now update types and config, create the stub adapter, and register it:

Editedtypes.ts

Editedconfig.ts

Ran command

Now create the stub adapter:

Editedindex.ts

Now register it:

Editedindex.ts

Ran command

Now build shared types and add the Amp adapter to the test file:

Editedadapters.test.ts

Now add the Amp adapter to the test file — add the import and fixture-backed adapter:

Editedadapters.test.ts

Readadapters.test.ts

Now let's also add a background fixture for the Amp adapter. Let me check the existing pattern at the bottom of the backgroundFixtures object:

Editedadapters.test.ts

Now let's add the amp background fixture. Let me find the closing bracket of backgroundFixtures:

Ran command

Now let's run the tests to see them fail:

9 failing tests against the stub, exactly as expected. All existing tests still pass. Here's the summary:

Created in the feat/amp-adapter worktree:

docs/projects/amp-adapter.md — Project plan with phases
packages/shared/src/agent.ts — Added 'amp' to AgentId
cli/src/types.ts — Added 'amp' to CLI AgentId
cli/src/config.ts — Added amp storage path (~/.local/share/amp)
cli/src/adapters/amp/v1.ts — Stub adapter with TODO implementations
cli/src/adapters/index.ts — Registered AmpAdapter
cli/test/fixture/amp/ — Fixtures (normal thread with tool calls/thinking, empty thread, history.jsonl)
cli/test/core/adapters.test.ts — Added Amp to adapter contract tests + background fixtures

9 tests failing against the stub — ready to implement. Want me to start filling in the adapter?

Yep! Also, make sure you're staging changes in incremental, reversible commits

Ran command

Let me commit the foundation first, then implement and commit incrementally.

Ran command

Good, 3 clean commits. Now let me implement the adapter:

Ran command

Now let's run the tests:

Ran command

All 133 tests pass, including all 9 Amp adapter tests. Let me also run the full CLI test suite to be safe:

Ran command

The one failure is a pre-existing flaky OpenCode test, not related to our changes. Let me verify:

Ran command

Confirmed — that test fails on main too. Not our issue. Let me commit the implementation:

Ran command

Done! 4 incremental, reversible commits:

Types + config + project plan — adds 'amp' AgentId and storage path
Stub adapter + registration — wires up the empty adapter
Fixtures + failing tests — golden fixtures and 9 failing contract tests
Full implementation — all 9 tests pass, 0 regressions

The adapter handles all Amp content block types (text, thinking, tool_use, tool_result), extracts model info, supports getCurrentTraceHint via session.json, and has live subscribe via fs.watch. Ready for manual testing or PR!

Okay awesome. How is the amp adapter different than others? How does amp store sessions differently, and perhaps, how should we modiy our frontend to make sure things like interruptions, attachments and other transforms are correctly handled?

Good. Now I have the full picture. Let me implement all the changes across the worktree. I'll do this in parallel tasks:

Ran taskUpdate adapter: handle interruptions, streaming, toolName tracking

GreppedagentColor|agent_color|agent-color|amp.*color

Let me check the TUI theme and then implement everything together.

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