# Session Report

**Session ID:** 8662e81c-fa81-4ddc-a140-ef6dddcaf381

---

## Step 1: User Turn

### System Prompt

```
You are an expert Haskell and Bash programmer specialized in writing clean, idiomatic, and efficient Haskell code.
When writing Bash code:
- Avoid bash-specific logic but bash-ism are fine.
- Document required shell tools at the top of the bash script.
When writing Haskell code:
- Use modern Haskell practices (base >= 4.14)
- Prefer pure functions and explicit type signatures
- Use standard libraries when appropriate
- Add clear comments for complex logic
- Follow consistent formatting
Use list-files to explore the project structure, read-file to understand existing code, write-file to create or modify files, and check-code to verify your work.
Always compile code before considering the job done.
Your output format may be stored as commit message: hence the first line of your last message should be a summary line.
```

### User Query

# Add PostgREST toolbox configuration support to Agent

Depends-on: #134
Base-branch: main
Final: false

## Summary

Add configuration support for PostgREST toolboxes to the Agent type in `System.Agents.Base`, similar to how OpenAPI toolboxes are currently configured. This enables users to configure PostgREST database APIs directly in their agent JSON configuration files.

## Dependencies

This issue depends on #134 (PostgREST toolbox core implementation) which provides:
- `System.Agents.Tools.PostgREST.Types` with `Config` type
- `System.Agents.Tools.PostgRESToolbox` with initialization functions
- `System.Agents.Tools.PostgREST.Converter` with tool registration

## Proposed Changes

### 1. Add PostgREST Types to `src/System/Agents/Base.hs`

Following the same pattern as `OpenAPIServerDescription` and `OpenAPIToolboxDescription`:

```haskell
-------------------------------------------------------------------------------
-- PostgREST Toolbox Configuration
-------------------------------------------------------------------------------

-- | Configuration for a PostgREST toolbox.
--
-- This describes a PostgREST API to load as a toolbox.
-- PostgREST exposes PostgreSQL databases as REST APIs and provides
-- an OpenAPI/Swagger spec at the root endpoint.
--
-- The toolbox will fetch the spec from 'postgrestSpecUrl' and make
-- all table endpoints available as tools to the agent, with special
-- handling for row filters, pagination, ordering, and column selection.
--
-- Example configuration:
--
-- @
-- {
--   "tag": "PostgRESTServer",
--   "contents": {
--     "specUrl": "http://localhost:3000/",
--     "baseUrl": "http://localhost:3000",
--     "headers": {"Accept-Profile": "myschema"},
--     "token": "${POSTGREST_TOKEN}"
--   }
-- }
-- @
data PostgRESTServerDescription
    = PostgRESTServerDescription
    { postgrestSpecUrl :: Text
    -- ^ URL to fetch the PostgREST OpenAPI specification from
    -- (usually the root endpoint, e.g., "http://localhost:3000/")
    , postgrestBaseUrl :: Text
    -- ^ Base URL for API calls (can be different from spec URL)
    , postgrestHeaders :: Maybe (Map Text Text)
    -- ^ Optional static headers to include in all requests
    -- (e.g., for schema selection via Accept-Profile)
    , postgrestToken :: Maybe Text
    -- ^ Optional Bearer token for JWT authentication
    }
    deriving (Show, Ord, Eq, Generic)

-- | Custom JSON options for PostgRESTServerDescription to use camelCase field names
postgrestServerOptions :: Aeson.Options
postgrestServerOptions = Aeson.defaultOptions
    { Aeson.fieldLabelModifier = dropPrefix "postgrest"
    , Aeson.omitNothingFields = True
    }
  where
    dropPrefix prefix str
        | take (length prefix) str == prefix = drop (length prefix) str
        | otherwise = str

instance ToJSON PostgRESTServerDescription where
    toJSON = Aeson.genericToJSON postgrestServerOptions
    toEncoding = Aeson.genericToEncoding postgrestServerOptions

instance FromJSON PostgRESTServerDescription where
    parseJSON = Aeson.genericParseJSON postgrestServerOptions

-- | Wrapper type for JSON serialization with tag.
-- Similar to OpenAPIToolboxDescription, this allows extensible toolbox types.
data PostgRESTToolboxDescription
    = PostgRESTServer PostgRESTServerDescription
    deriving (Show, Ord, Eq, Generic)

instance ToJSON PostgRESTToolboxDescription where
    toJSON (PostgRESTServer val) =
        Aeson.object
            [ "tag" .= ("PostgRESTServer" :: Text)
            , "contents" .= val
            ]

instance FromJSON PostgRESTToolboxDescription where
    parseJSON = Aeson.withObject "PostgRESTToolboxDescription" $ \v -> do
        tag <- v .: "tag"
        case (tag :: Text) of
            "PostgRESTServer" ->
                PostgRESTServer <$> v .: "contents"
            _ -> fail "expecting PostgRESTServer 'tag'"
```

### 2. Update the `Agent` type

Add the `postgrestToolboxes` field to the `Agent` record:

```haskell
data Agent
    = Agent
    { slug :: Text
    , apiKeyId :: Text
    , flavor :: Text
    , modelUrl :: Text
    , modelName :: Text
    , announce :: Text
    , systemPrompt :: [Text]
    , toolDirectory :: FilePath
    , mcpServers :: Maybe [McpServerDescription]
    , openApiToolboxes :: Maybe [OpenAPIToolboxDescription]
    , postgrestToolboxes :: Maybe [PostgRESTToolboxDescription]  -- ^ NEW
    , extraAgents :: Maybe [ExtraAgentRef]
    }
    deriving (Show, Ord, Eq, Generic)

-- Update agentOptions to include the new field
agentOptions :: Aeson.Options
agentOptions = Aeson.defaultOptions
    { Aeson.fieldLabelModifier = id
    , Aeson.omitNothingFields = True
    }
```

### 3. Update Initialization in `src/System/Agents/AgentTree.hs`

Add trace event for PostgREST:

```haskell
data Trace
    = AgentTrace Runtime.Trace
    | McpTrace McpServerDescription McpTools.Trace
    | OpenAPITrace OpenAPIToolboxDescription OpenAPIToolbox.Trace
    | PostgRESTTrace PostgRESTToolboxDescription PostgREST.Trace  -- ^ NEW
    | DataLoadingTrace FileLoader.Trace
    | ConfigLoadedTrace AgentConfigTree
    | CyclicReferencesWarning [[AgentSlug]]
    | ReferenceValidationTrace ReferenceValidationTrace
    deriving (Show)
```

Add configuration conversion function:

```haskell
-- | Convert PostgREST toolbox description to toolbox configuration.
postgrestDescToConfig :: PostgRESTServerDescription -> PostgREST.Config
postgrestDescToConfig desc =
    PostgREST.Config
        { PostgREST.configUrl = postgrestSpecUrl desc
        , PostgREST.configBaseUrl = postgrestBaseUrl desc
        , PostgREST.configHeaders = Maybe.fromMaybe Map.empty (postgrestHeaders desc)
        , PostgREST.configToken = postgrestToken desc
        }
```

Add initialization function for PostgREST toolboxes (similar to `initializeOpenAPIToolboxes`):

```haskell
-- | Initialize PostgREST toolboxes and return their tool registrations.
--
-- This function takes PostgREST toolbox descriptions, initializes each toolbox,
-- and registers all tools. If any toolbox fails to initialize, an error is returned.
initializePostgRESToolboxes ::
    Tracer IO Trace ->
    [PostgRESTToolboxDescription] ->
    IO (Either LoadingError [ToolRegistration])
initializePostgRESToolboxes tracer descriptions = do
    results <- mapM initializeOne descriptions
    case concatEithers results of
        Left [] -> pure $ Left $ OtherError "Unknown PostgREST initialization error"
        Left (err : _) -> pure $ Left err  -- Return first error
        Right allTools -> pure $ Right $ concat allTools
  where
    initializeOne :: PostgRESTToolboxDescription -> IO (Either LoadingError [ToolRegistration])
    initializeOne desc@(PostgRESTServer srvDesc) = do
        let config = postgrestDescToConfig srvDesc
        initResult <- PostgREST.initializeToolbox (contramap (PostgRESTTrace desc) tracer) config
        case initResult of
            Left err ->
                pure $ Left $ PostgRESTInitError (postgrestSpecUrl srvDesc) (show err)
            Right toolbox -> do
                regResult <- registerPostgRESTools toolbox
                case regResult of
                    Left err ->
                        pure $ Left $ PostgRESTInitError (postgrestSpecUrl srvDesc) err
                    Right tools ->
                        pure $ Right tools

    concatEithers :: [Either a b] -> Either [a] [b]
    concatEithers eithers =
        let (lefts, rights) = Either.partitionEithers eithers
         in if null lefts then Right rights else Left lefts
```

Add new error constructor:

```haskell
data LoadingError
    = AgentLoadingError FileLoader.InvalidAgentError
    | ReferenceError ReferenceError
    | OpenAPIInitError Text String  -- ^ Description and error message
    | PostgRESTInitError Text String  -- ^ NEW: Description and error message
    | OtherError String
    deriving (Show)
```

Update the agent initialization functions to include PostgREST toolboxes:

```haskell
initAgentTreeAgentDeferred :: ...
initAgentTreeAgentDeferred tracer keys modifyPrompt agentToTool' helperAgents _extraSlugs rootDir (AgentDescription desc) = do
    case (lookup desc.apiKeyId keys, OpenAI.parseFlavor desc.flavor) of
        (_, Nothing) -> pure $ Left ("could not parse flavor " <> Text.unpack desc.flavor)
        (Nothing, _) -> pure $ Left ("could not find key " <> Text.unpack desc.apiKeyId)
        (Just key, Just flavor) -> do
            mcpToolboxes <- traverse startMcp (Maybe.fromMaybe [] desc.mcpServers)
            
            -- Initialize OpenAPI toolboxes
            openApiToolsResult <- initializeOpenAPIToolboxes tracer (Maybe.fromMaybe [] desc.openApiToolboxes)
            
            -- Initialize PostgREST toolboxes (NEW)
            postgrestToolsResult <- initializePostgRESToolboxes tracer (Maybe.fromMaybe [] desc.postgrestToolboxes)
            
            case (openApiToolsResult, postgrestToolsResult) of
                (Left err, _) -> pure $ Left (show err)
                (_, Left err) -> pure $ Left (show err)  -- NEW
                (Right openApiToolRegs, Right postgrestToolRegs) -> do
                    Runtime.newRuntime
                        desc.slug
                        desc.announce
                        (contramap AgentTrace tracer)
                        key
                        (OpenAI.Model flavor ...)
                        (rootDir </> desc.toolDirectory)
                        [agentToTool' rt | rt <- helperAgents]
                        mcpToolboxes
                        (openApiToolRegs ++ postgrestToolRegs)  -- ^ Combined tool registrations
```

Similarly update `initAgentTreeAgent`.

### 4. Update Runtime in `src/System/Agents/Runtime/Runtime.hs`

No changes needed - the Runtime already accepts a list of pre-initialized tool registrations (`[ToolRegistration]`). The PostgREST tools will be passed alongside OpenAPI tools.

## Example Agent Configuration

Users can configure PostgREST toolboxes in their agent JSON:

```json
{
  "slug": "db-agent",
  "apiKeyId": "main-key",
  "flavor": "OpenAIv1",
  "modelUrl": "https://api.openai.com/v1",
  "modelName": "gpt-4-turbo",
  "announce": "an agent that can query the company database",
  "systemPrompt": [
    "You are a database assistant.",
    "Use the available database tools to answer user queries."
  ],
  "toolDirectory": "tools",
  "mcpServers": [],
  "openApiToolboxes": [],
  "postgrestToolboxes": [
    {
      "tag": "PostgRESTServer",
      "contents": {
        "specUrl": "http://localhost:3000/",
        "baseUrl": "http://localhost:3000",
        "headers": {
          "Accept-Profile": "public"
        },
        "token": "${POSTGREST_JWT}"
      }
    }
  ],
  "extraAgents": []
}
```

## Testing Strategy

1. **Unit tests** in `test/AgentConfigTests.hs`:
   - Parse `PostgRESTServerDescription` from JSON
   - Round-trip serialization/deserialization
   - Error handling for missing required fields

2. **Integration tests**:
   - Initialize agent with PostgREST toolbox configuration
   - Verify tools are registered with correct names
   - Verify trace events are emitted

## Files to Modify

| File | Changes |
|------|---------|
| `src/System/Agents/Base.hs` | Add `PostgRESTServerDescription`, `PostgRESTToolboxDescription`, update `Agent` type |
| `src/System/Agents/AgentTree.hs` | Add `PostgRESTTrace`, `postgrestDescToConfig`, `initializePostgRESToolboxes`, update `LoadingError`, update `initAgentTreeAgent*` |
| `app/Main.hs` | Add trace serialization for `PostgRESTTrace` in `toJsonTrace` (optional) |

## Backward Compatibility

The `postgrestToolboxes` field is optional (`Maybe`), so existing agent configurations without this field will continue to work without modification.

## Tradeoffs

1. **Separate vs Unified Toolbox Description**: 
   - **Chosen**: Separate `PostgRESTToolboxDescription` type
   - **Rationale**: PostgREST has different semantics than generic OpenAPI (row filters, pagination structure). Keeping them separate allows future PostgREST-specific options.
   - **Alternative**: Could extend OpenAPI description, but this would clutter the OpenAPI path with PostgREST-specific handling.

2. **Tool Name Prefix**:
   - PostgREST tools use `postgrest_` prefix (e.g., `postgrest_localhost_get_users`)
   - This distinguishes them from `openapi_` prefixed tools

## Future Enhancements (Out of Scope)

- Environment variable substitution in configuration (e.g., `"token": "${POSTGREST_TOKEN}"`)
- Multiple schema selection (PostgREST can expose multiple schemas)
- Connection pooling configuration
- Retry/backoff configuration for failed requests





---
Please mention issue #135 in the commit message.



### Available Tools

- **bash_grep-files** (`bash_grep-files`)
  - Description: Search for a pattern in files using 'git grep'
- **bash_check-code** (`bash_check-code`)
  - Description: Check Haskell code by compiling or testing
- **bash_write-file** (`bash_write-file`)
  - Description: Write content to a file
- **bash_list-files** (`bash_list-files`)
  - Description: List all files in the project
- **bash_read-file** (`bash_read-file`)
  - Description: Read the contents of a file

---

## Step 2: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Let me start by exploring the project structure to understand the codebase and then implement the changes described in the issue.
</details>

### Response



### Tool Calls

- **bash_list-files**

---

## Step 3: User Turn



---

## Step 4: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Let me look at the main files I need to modify:
1. `src/System/Agents/Base.hs` - Add PostgREST types and update Agent type
2. `src/System/Agents/AgentTree.hs` - Add initialization functions

Let me first read these files to understand the current structure.
</details>

### Response



### Tool Calls

- **bash_read-file**
- **bash_read-file**

---

## Step 5: User Turn



---

## Step 6: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Now let me look at the PostgREST toolbox implementation to understand the types and interfaces I need to use:
</details>

### Response

Let me also look at the PostgREST toolbox files to understand the types and interface:

### Tool Calls

- **bash_read-file**
- **bash_read-file**
- **bash_read-file**

---

## Step 7: User Turn



---

## Step 8: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Now I have a good understanding of the codebase. Let me also check if there's an `app/Main.hs` file that might need updates:
</details>

### Response

Now let me check the Main.hs file and also look at any existing tests to understand the structure better:

### Tool Calls

- **bash_read-file**
- **bash_read-file**

---

## Step 9: User Turn



---

## Step 10: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Now I have a good understanding of the codebase. Let me implement the changes:

1. First, I'll modify `src/System/Agents/Base.hs` to add the PostgREST types and update the Agent type
2. Then, I'll modify `src/System/Agents/AgentTree.hs` to add the Trace, initialization functions, and update the agent initialization

Let me start by implementing the changes:
</details>

### Response

Now I have a complete understanding of the codebase. Let me implement the changes as specified in the issue. I'll start with the `Base.hs` file:

### Tool Calls

- **bash_write-file**

---

## Step 11: User Turn



---

## Step 12: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Now let me update the AgentTree.hs file to add PostgREST support:
</details>

### Response

Now let me update the `AgentTree.hs` file to add PostgREST support:

### Tool Calls

- **bash_write-file**

---

## Step 13: User Turn



---

## Step 14: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Now I need to check if there's a registration function for PostgREST tools in the PostgREST.Converter module. Let me look at the imports more carefully.
</details>

### Response

Now let me check if the `registerPostgRESTools` function exists in the Converter module:

### Tool Calls

- **bash_read-file**

---

## Step 15: User Turn



---

## Step 16: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

I see that the `registerPostgRESTools` function is not exported from `PostgREST.Converter`. Looking at the OpenAPI toolbox, let me check where `registerOpenAPITools` is defined and see if I need to add a similar function for PostgREST.
</details>

### Response

Let me check where `registerOpenAPITools` is defined:

### Tool Calls

- **bash_grep-files**

---

## Step 17: User Turn



---

## Step 18: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Let me look at the ToolRegistration module to understand how to add the PostgREST registration function:
</details>

### Response



### Tool Calls

- **bash_read-file**

---

## Step 19: User Turn



---

## Step 20: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

I see that the `registerPostgRESTools` and `registerPostgRESTool` functions are already defined in `ToolRegistration.hs`. Now let me compile the code to see if there are any issues:
</details>

### Response

Good, the `registerPostgRESTools` function is already defined in `ToolRegistration.hs`. Now let me try to compile the code:

### Tool Calls

- **bash_check-code**

---

## Step 21: User Turn



---

## Step 22: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

The code compiles with warnings. Now I need to fix the warnings by:

1. Adding the `postgrestToolboxes` field to the Agent initialization in `app/Main.hs` (the Initialize command)
2. Adding a pattern match for `PostgRESTTrace` in the `toJsonTrace` function in `app/Main.hs`
3. Fixing the pattern matches in `CLI/TraceUtils.hs` to handle `PostgRESTTrace`
4. Fixing test files to include the new field

Let me fix the issues:
</details>

### Response

The code compiles, but there are some warnings. Let me fix the missing pattern matches and field initializations. First, let me update `app/Main.hs`:

### Tool Calls

- **bash_read-file**

---

## Step 23: User Turn



---

## Step 24: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

I need to update `app/Main.hs` to:
1. Add the missing `postgrestToolboxes = Nothing` field to the Agent initialization
2. Add a pattern match for `PostgRESTTrace` in the `toJsonTrace` function

Let me fix these issues:
</details>

### Response

I need to update `app/Main.hs` to fix the warnings. Let me make the necessary changes:

### Tool Calls

- **bash_write-file**

---

## Step 25: User Turn



---

## Step 26: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Now let me also update the `CLI/TraceUtils.hs` file to handle the `PostgRESTTrace` pattern:
</details>

### Response

Now let me update `CLI/TraceUtils.hs` to handle the `PostgRESTTrace` pattern:

### Tool Calls

- **bash_read-file**

---

## Step 27: User Turn



---

## Step 28: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

I need to update this file to add the `PostgRESTTrace` pattern. Let me fix it:
</details>

### Response



### Tool Calls

- **bash_write-file**

---

## Step 29: User Turn



---

## Step 30: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Now let me also update the test file to include the new field. Let me look at the test file to make the necessary updates.
</details>

### Response

Now let me update the test file to include the new `postgrestToolboxes` field:

### Tool Calls

- **bash_write-file**

---

## Step 31: User Turn



---

## Step 32: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

Now let me compile again to check if all warnings have been resolved:
</details>

### Response

Now let me compile again to verify everything works correctly:

### Tool Calls

- **bash_check-code**

---

## Step 33: User Turn



---

## Step 34: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

The code compiles successfully. Let me run the tests to make sure everything passes:
</details>

### Response

The code compiles successfully. Let me run the tests to make sure everything passes:

### Tool Calls

- **bash_check-code**

---

## Step 35: User Turn



---

## Step 36: LLM Turn

### Thinking Process

<details>
<summary>Click to expand reasoning</summary>

All 135 tests passed! Let me provide a summary of the changes made to implement the PostgREST toolbox configuration support.
</details>

### Response

All 135 tests pass. Let me provide a summary of the changes made:

## Summary

I have successfully implemented PostgREST toolbox configuration support for the Agent type in `System.Agents.Base`, similar to how OpenAPI toolboxes are configured. Here's what was changed:

### Changes Made

1. **`src/System/Agents/Base.hs`** - Added PostgREST types:
   - `PostgRESTServerDescription` - Configuration for a PostgREST server (specUrl, baseUrl, headers, token)
   - `PostgRESTToolboxDescription` - Wrapper type with tag-based JSON serialization
   - Added `postgrestToolboxes` field to the `Agent` record

2. **`src/System/Agents/AgentTree.hs`** - Added initialization support:
   - Added `PostgRESTTrace` constructor to the `Trace` type
   - Added `PostgRESTInitError` constructor to the `LoadingError` type
   - Added `postgrestDescToConfig` function to convert descriptions to toolbox configs
   - Added `initializePostgRESToolboxes` function for toolbox initialization
   - Updated `initAgentTreeAgent` and `initAgentTreeAgentDeferred` to initialize PostgREST toolboxes alongside OpenAPI toolboxes

3. **`app/Main.hs`** - Fixed pattern matches and field initialization:
   - Added `postgrestToolboxes = Nothing` to the Initialize command's agent
   - Added `PostgRESTTrace` pattern match in `toJsonTrace` function

4. **`src/System/Agents/CLI/TraceUtils.hs`** - Added pattern matches:
   - Added `PostgRESTTrace` patterns to `tracePrintingTextResponses` and `traceUsefulPromptHandle`

5. **`test/Main.hs`** - Updated tests:
   - Added `postgrestToolboxes = Nothing` to all test agent constructions

### Backward Compatibility

The `postgrestToolboxes` field is optional (`Maybe [PostgRESTToolboxDescription]`), so existing agent configurations without this field will continue to work without modification.

### Example Configuration

Users can now configure PostgREST toolboxes in their agent JSON:

```json
{
  "slug": "db-agent",
  "apiKeyId": "main-key",
  "flavor": "OpenAIv1",
  ...
  "postgrestToolboxes": [
    {
      "tag": "PostgRESTServer",
      "contents": {
        "specUrl": "http://localhost:3000/",
        "baseUrl": "http://localhost:3000",
        "headers": {
          "Accept-Profile": "public"
        },
        "token": "${POSTGREST_JWT}"
      }
    }
  ]
}
```

The implementation follows the same patterns as OpenAPI toolbox configuration, providing a consistent experience for users configuring external toolboxes. Issue #135 is addressed.
